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led driver series for lcd back light white led driver for medium sized a nd large sized lcd back light bd9470a efv ? bd9 470a fm general description BD9470AEFV and bd9470afm are high efficiency driver for white led. t hey are designed for large sized lcd. bd 9470aefv and bd9470afm are built - in dcdc converter that supply appropriate voltage for light source . BD9470AEFV and bd9470afm are also built - in protection function for abnormal state such as ovp: over voltage protection, ocp: over current limit protection of dcdc, scp: short circuit protection, open detection of led string . t hus they are used for conditions of large output voltage and load conditions. features ? 6ch led constant current driver ? led maximum output current 250ma ? individual pwm dimming modulation allowed for leds ? 2% led current accuracy (when each led is set to 130ma) ? built -in led feedback voltage automatic adjustment circuit according to led current ? built -in start - up circuit independent of pwm light modulation ? built - in vout ? fb voltage maintenance function when pwm=low 0% ? built -in led current stabilization circuit while scanning operation is performed ? built -in vout discharge circuit w hile shutdown ? built -in led protection (open / short protection) ? individual detection and individual led off for both open and short circuit ? adjustable led short - circuit protection threshold ? pwm - independent led protection ? vout over voltage protection (ovp) and reduced voltage protection (scp) circuit ? built -in failure indication function ? built -in iset pin short - circuit protection cir c uit key specification s ? vcc supply voltage range: 9.0v 35.0v ? led minimum output current: 40 ma ? led maximum output current: 25 0ma ? dcdc oscillation frequency: 15 0khz(rt=100kohm) ? operation circuit current: 6ma(typ.) ? operating temperature range : - 40 85 applications led driver for tv, monitor and lcd back light package w ( typ.) x d(typ.) x h(max.) hsop - m28 18.50mm x 9.90mm x 2.41mm htssop-b28 9.7 0mm x 6.4 0mm x 1.00 mm typical application circuit figure 3. typical application circuit figure 1. hsop - m28 figure 2. htssop - b28 stb vcc reg58 gnd fb ss rt led6 pwm4 pwm6 dcdc_gnd n iset cs pwm1 pwm2 lsp pwm3 pwm5 fail ovp led5 led4 led_gnd led3 led2 led1 uvlo vin stb pwm fail product structure silicon monolithic integrated circuit this product is not designed protection against radioactive rays 1/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 14 ? 001 datashee t
b d9470afm ? BD9470AEFV 1. specification for bd9470a efv ? bd9470a fm absolute maximum ratings (ta = 25 c) parameter symbol rating unit ovp detect voltage (dcdc stop) vcc - 0.3~36 v led1~ 6 pin voltage led1~ 6 - 0.3~40 v stb ? fail ? uvlo ? ovp pin voltage stb,fail ,uvlo,ovp - 0.3~ 36 v iset ? fb ? ss ? cs ? n ? reg58 ? rt pin voltage iset ? fb ? ss ? cs ? n ? reg58 ? rt - 0.3~7 v pwm1~6 ? lsp pwm1~6 ? lsp - 0.3~16 power dissipation (hsop-m 28)*1 pd 5208 mw power dissipation (htssop-b28)*2 pd 4700 mw operating temperature range topr -40 +85 storage temperature ra nge ts t g -55 +150 m aximum junction temperature tjmax +150 *1 decreases - 41.7 mw/ c at ta=25 c or higher (when mounting a four - layer 70.0mmx70.0mmx1.6mm board) *2 decreases - 37.6 mw/ c at ta=25 c or higher (when mounting a four - layer 70.0mmx70.0mmx1.6m m board) recommended operating rating s parameter symbol rating unit s upply voltage vcc 9.0 35.0 v led1 -4 pin minimum output current iled_min 40 ma *1 led1 -4 pin maximum output current iled_max 2 50 ma *1*2*3 lsp input voltage range vlsp 0.3 2 .5 v dc/ dc oscillation frequency fsw 100 500 khz min. on - duty for pwm light modulation pwm_min 30 s *1 the amount of current per channel *2 if led makes significant variations in its reference voltage vf, the driver will increase power dissipation, resulting in a rise in package temperature. to avoid this problem, design the board with thorough consideration given to heat radiation measures . *3 the led current can be set up to 250ma pin con f iguration ( top view ) outline dimension diagrams/sign diagrams lot no. bd9470afm bd9470a efv lot no. figure 4. pin con f iguration top view figure 5. outline dimension diagrams/sign diagrams gnd led6 pwm4 pwm6 iset pwm1 pwm2 pwm3 pwm5 fail ovp led5 led4 led_gnd 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 stb vcc reg58 fb ss rt dcdc_gnd n cs lsp led3 led2 led1 uvlo 7.ss 1.reg58 2.cs 3.n 4.dcdc_gnd 5.rt 6.fb 8.iset 9.pwm1 10.pwm2 11.pwm3 12.pwm4 13.pwm5 14.pwm6 15.gnd 16.fail 18.led6 17.ovp 19.led5 21.led_gnd 20.led4 22.led3 24.led1 23.led2 25.uvlo 27.stb 26.lsp 28.vcc 2/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV contents 1. specification for bd9470a efv ? bd9470a fm p2 p9 absolute maximum ratings p2 recommended operating rating s p2 pin con f iguration p2 outline dimension diagrams/sign diagrams p2 electrical characteristics p4,p5 pin numbers, names, and functions p6 external component recommended range p6 internal equivalent circuit diagrams p7 block diagram p8 characteristic date p8,p9 2. understanding bd9470a efv ? bd9470a fm p10 p12 pin functions p10 p12 3. application of bd9470a efv ? bd9470a fm p13 p32 3.1 BD9470AEFV , bd9470afm examination for application p13 p27 start - up and ss capacity setting explan ation p13,p14 the setting of reg58 capacity and shutdown procedure p15 vcc series resistance setting procedure p16 the necessity for holding output voltage and fb voltage while pwm=low p17,p18 explanation of v out ovp voltage holding function when pwm=low p19,p20 fb current source mode ? sink/source mode p21,p22 led current setting p23 dc/dc converter drive frequency setting p23 uvlo setting procedure p24 ovp/scp setting method p25 lsp setting procedure p26 timer latch function p27 3. 2 selection of dcdc components p28 p30 ocp setting procedure/dcdc component current tolerance selection procedur e p28,p29 selection of inductor l p30 selection of switching mosfet transistors p30 selection of rectifier diodes p30 3.3 timing chart p31 3.4 list of protection function p32 4. caution on use p33 5. ordering informatio n p34 6. r evision history p35 3/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV electrical characteristics (unless otherwise specified, ta = 25 c, vcc=24v ) parameter symbol specification unit condition min typ max whole dev ice operation circuit icc 5.5 8.5 ma stb=3v, pwm1 -6= 3.3 v standby current ist 40 80 a stb=0v uvlo block operating voltage ( vcc vuvlo_vcc 6.5 7.5 8.5 v vcc=sweep up hysteresis voltage vcc vuhys_vcc 150 300 600 mv vcc=sweep down uvlo release voltage vuvlo_u 2.88 3.00 3.12 v vuvlo=sweep up uvlo hysteresis voltage vuhys_u 250 300 350 mv vuvlo=sweep down uvlo pin leakage current uvlo_lk -2 0 2 a vuvlo=4v dc/dc block error amp. reference voltage (min) vled 0.36 0.40 0.44 v ledx terminal ile dx = 4 0ma error amp. basic voltage (iled=130ma) vled 0.428 0.450 0.472 v ledx terminal iledx = 130ma oscillation frequency fct 142.5 150 157. 5 khz rt=100kohm max. duty cycle of output n nmax_duty 90 95 99 % rt=100kohm rt short protection range rt_det - 0.3 - vrt 90% v rt =sweep down on resistance on n pin source side ronso 1.5 3 6 on resistance on n pin sink side ronsi 1.5 3 6 rt pin voltage vrt 1 1.5 2 v rt=100kohm ss pin source current issso - 2.6 - 2.0 -1. 4 a vss=2v soft start completion voltage vss_end 3.52 3.70 3.88 v ss=sweep up fb source current ifbso -115 -100 -85 a vled=0v, vfb=1.0v fb sink current ifbsi 70 100 130 a vl ed= 5 .0v(all_ch), vfb= 1.0 v ,vss=4v fb source mode ss pin input voltage range fb_so_ss 4.9 - - v ss=sweep up fb sink/source mode ss pin input voltage range fb_sosi_ss 3.9 - 4.4 v ss=sweep down ove r current detect voltage vcs 3 72 400 4 28 mv cs =sweep up cs source current ics 15 30 60 a vcs=0v dc/dc protection block ovp detect voltage (dcdc stop) vovp 2.90 3 .00 3.1 0 v vovp sweep up ovp protection timer release vovp_can vovp- 0.14 vovp- 0.1 vovp-0 .04 v vovp sweep down short protection detect voltage vscp 0.05 0.1 0.15 v vovp sweep down ovp pin leakage current ovp_lk -2 0 2 a vovp=4v 4/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV electrical characteristics (unless otherwise specified, ta = 25 c, vcc=24v) parameter symbol specification uni t condition min typ max led driver block led pin current accuracy1 S iled1 -2 - 2 % iled=1 3 0ma led pin current accuracy2 S iled2 -2 .5 - 2 .5 % iled=1 5 0ma led pin leakage current S iled3 - 3.5 3.5 % iled= 25 0ma iset pin voltage illed - 0.8 - 0.8 ua stb=h, pwmx=l, ledx=40v led pin current accuracy1 viset 1.3 1.5 1.7 v riset=30k led protection block iset short circuit protection range iset_det - 0.3 - viset90% v iset=sweep down led short protection voltage vlsp 8.5 9 9.5 v ledx=sweepup, lsp=op en lsp pin resistive divider(higher r) rulsp 186 0 3 100 5580 k lsp=0v lsp pin resistive divider(lower r) rdlsp 540 900 1620 k lsp=4v led open detect voltage vopen 0.1 5 0.20 0.25 v ledx=sweep down reg 58 block reg58 output voltage 1 reg 58_1 5.742 5. 8 5.858 v io=0ma reg58 output voltage 2 reg 58_2 5.713 5.8 5.887 v io= -15ma reg58 max output current | ireg 58 | 15 - ma reg58_uvlodetect voltage reg 58 _th 2.1 2.4 2.7 v stb=on reg 58 =sweep down reg58_uvlo hysteresis reg 58 _hys 100 200 400 mv stb=on - >o ff reg 58 =sweep down reg58 discharge current reg 58 _dis 3.0 5.0 7.0 ua stb=on- >off reg 58 =4v stb block stb pin high voltage stbh 2 - 35 v stb=sweep up stb pin low voltage stbl - 0.3 - 0.8 v stb=sweep down stb pin pull down resistance rstb 600 1000 1800 k vstb=3.0v pwm block pwm pin high voltage pwm_h 1.5 - 15 v pwm =sweep up pwm pin low voltage pwm_l - 0.3 - 0.8 v pwm =sweep down pwm pin pull down resistance rpwm 1200 2000 3600 k pwm =3.0v fail block open drain fail pin ron rfail 250 500 1 000 vfail=1.0v fail pin leakage current ilfail -2 0 2 a vfail=5v 5/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV pin numbers/names/functions pin no. hsop -m 28 pin name htssop-b28 symbol function 1 8 iset led current setting resistor connection pin 2 9 pwm1 pwm light modulation signal input pin for led1 3 10 pwm2 pwm light modulation signal input pin for led2 4 11 pwm3 pwm light modulation signal input pin for led3 5 12 pwm4 pwm light modulation signal input pin for led4 6 13 pwm5 pwm light modulation signal input pin for led5 7 14 pwm6 pw m light modulation signal input pin for led6 8 15 gnd ground pin for analog block 9 16 fail error detection output pin 10 17 ovp overvoltage protection detection pin 11 18 led6 led output 6 12 19 led5 led output 5 13 20 led4 led output 4 14 21 led_g nd ground pin for led 15 22 led3 led output 3 16 23 led2 led output 2 17 24 led1 led output 1 18 25 uvlo detection pin for under voltage lockout prevention 19 26 lsp led short - circuit protection voltage setting pin 20 27 stb enable pin 21 28 vcc p ower supply pin 22 1 reg58 5.8v regulator output pin / shutdown timer pin 23 2 cs dc/dc output current detection pin ocp detection pin 24 3 n dc/dc switching output pin 25 4 dcdc_gnd dc/dc gnd pin 26 5 rt dcd c drive frequency setting connection pin 27 6 fb error amp output pin 28 7 ss slow start/ l ed protection masking time setting pin external component recommended range parameter symbol specification unit vcc pin connecting capacity cvcc 0.1 100 f vcc pin connecting resistance r vcc 0 *1 k reg58 pin connecting capacity c_reg 1.0 470 f soft start setting capacity css 0.001 1. 0 f rt pin connection resistance range rrt 30 150 k iset pin connecting resistance range riset 12.16 75 k the operating conditions listed above are constants for the ic alone. to make constant setting with practical set devices, utmost attention shou ld be paid. *1 please refer to 3.2 function explanatiob and selection of external components for thes election of vcc series resistance. 6/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV internal equivalent circuit diagrams reg58 / n / cs / dcdc_gnd ss fb reg58 n dcdc_gnd cs ss fb ovp iset rt ovp 100k 2k 4k 5v iset rt stb fail uvlo stb 1m 1m 5v fail 500 uvlo 1m 5v led1 - 6/led_gnd pwm lsp led1-6 led_gnd pwm1-6 2m 100k 5v lsp 4v 3.1m 900k 5v 100k fig ure 6. internal equivalent circuit diagrams 7/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV vreg ovp control logic current sence + - + - - - - pwm comp driver err amp current driver vcc stb fb dcdc_gnd cs n fail ovp uvlo reg58 rpc cpc c vcc vcc cout led4 led3 led2 led1 timer logic osc rt agnd uvlo (vcc) uvlo creg + open-short detect iset osdet + v in c in iset ledgnd tsd scp pwm1 pwm2 lsp 4v 3v ss pwm3 pwm4 os det ss css ss fb clamp ss_end ss_end led5 led6 - - pwm5 pwm6 1.5v 0.9v + reg58 use at at sink source mode block diagram characteristic date (reference date) fig ure 8. icc[ma] vs vcc[v] fig ure 9. reg58[v] vs vcc[v] fig ure 7. block diagram 3 4 5 6 7 8 9 10 9 14 19 24 29 34 vc c [v] icc[ma] 5.0 5.5 6.0 6.5 7.0 9 14 19 24 29 34 vc c [v] reg58[v] 8/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV fig ure 10. iled[ma] vs temp[ ] fig ure 11. ifb[ua] vs ledx[v] ( @iled=130ma) fig ure 12. ile dx[ma] vs riset[kohm] fig ure 13. fct [khz] vs rrt[kohm] 120 122 124 126 128 130 132 134 136 138 140 -40 -20 0 20 40 60 80 temp[ ] iled[ma] -160 -120 -80 -40 0 40 80 120 160 0.0 0.2 0.4 0.6 0.8 1.0 ledx[v] ifb[ua] 10 100 1000 10 100 riset[kohm] iledx[ma] 10 100 1000 10 100 1000 rrt[kohm] fct [ khz ] 9/ 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV 2. und erstanding bd9470a efv ? bd9470a fm pin functions iset htssop- b28:8pin/ hsop - m28 1pin t he iset pin is a resister value of output current setting. the output current iled vary in inverse proportion to resister value. the relation of the output current iled and iset pin connecting resistor riset are as bellow. h owever, current setting range is from 40ma to 15 0ma. and the setting of ise t resistor is bellow at using 15 0ma to 250ma. iled(ma) 150 160 170 180 190 200 210 220 230 240 250 rset(kohm) 20.00 18 .80 17.72 16.76 15.90 15.12 14.42 13.78 13.19 12.66 12.16 for a setting example, please refer to ? 3.1 application explanation / led current setti ng? . when the riset is shorted and the iset pin is grand shorted , the led current is off and the fail=open(a bnormal signal) to prevent flow ing a large current to led pin when it becomes less than viset 0.90v(typ). when the iset pin back to normal state the led current return to former system , too and the fail=gnd(normal signal). it prepare automatically to sui table led feedback voltage that c an output led current set by iset pin. in short led feedback voltage is dropped when the led current is small and the ic heating is held automatically. in case of a large cu rrent is needed , raise the led pin feedback voltag e. a nd it adjust automatically to led pin voltage that can be flow large led current. t he calculation is as below. t he led feedback voltage (vled) is clamped to 0.4v(typ.) when the led current (iled) is less than 115.6ma. pwm1 -6 htssop- b28:9,10,11,12,13,14pin / hsop - m28 2,3,4,5,6,7pin the on/off pin for led driver. light can be modulated by changing the duty cycle through the direct input of a pwm light modulation signal in each pwm pin. the high and low voltage levels of pwm_x pins are as listed in the table below. state pwm x voltage led on state pwm x =1.5v~ 1 5.0v led off state pwm x= \ 0.3v 0.8v the sequence of stb/pwm for start - up, please input pwm signal before stb or the same timing stb=pwm=on. gnd htssop- b28:15pin / hsop - m28 8pin ic internal a nalog gnd pin. fail htssop- b28:16pin / hsop - m28 9pin fail signal output pin open drain .internal nmos will become open while abnormal is detected. ovp htssop- b28:17pin / hso p- m28 10pin the ovp pin is an input pin for overvoltage protection and short circuit protection of dc/dc output voltage. if over voltage is detected, the ovp pin will stop the dc/dc converter conducting step - up operation. if vout was increased by abnormal ity , timer is set while ovp 2.9v(typ.).when it comes to ovp 3.0v, timer will on at the same time and to stop dcdc . although counter will be stopped when ovp 2.9v during counting time, in the state of ovp>2.9v, when internal counter completed 2 18 count 262152 count , the system will be latched. when the short circuit protection (scp) function is activated, the dc/dc converter will stop operation, and then the timer will start counting , after 2 16 count 65536 count , dcdc and led driver will stop and latch. th e ovp pin is of the high impedance type and involves no pull - down resistor, resulting in unstable potential in the open- circuit state. to avoid this problem, be sure to make input voltage setting with the use of a resistive divider or otherwise . ovp pin wi ll be feedback pin when pwm=l. also, th is pin will hold ovp voltage at that time when switch pwm = h to l . for setting example, refer to information in?3.4 selection of external components - ovp/scp setting procedure ovp voltage keep internal ic with pwm=low timing, and vout voltage can hold by using copied ovp voltage while pwm=low. the ovp keep voltage range is 0~3v, 30steps .for setting example, refer to information in ?3.2 selection of external components?, ?explanation of v out ovp voltage holding function when pwm=low ? state fail output normal gnd abnormal after timer latch open level ][ ][ 3000 ? = k ma i r led iset ][][462.3 vai vled led = ][)][(2653 9753.0 ? = ? k ma i r led iset 10/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV led1 - 6 htssop- b28:18,19,20,22,23,24pin / hsop - m28 11,12,13,15,16,17pin led constant current output pins . current value setting can be made by connecting a resistor to the iset pin . for the current value setting procedure, refer to the description of ?iset pin?. if any of the led pins is put in an abnormality state (short circuit mode, open circuit mode, ground short mode), the relevant protection function will be activated . ? led pin short circuit protection function ( lsp) w hen any le d is in short state (more than led=9.0v(typ)) the led short is detected. after abnormal detection , the timer count starts. the led that is abnormal detection after 2 16 count is stopped and other led driver operates normally. ? led pin open circuit protecti on function (lop) if any of the led pins becomes open - circuited (0.2v (typ.) or less), led_open will be detected. when this error is detected, the timer will start counting, when it completes counting the preset period of time, only led driver that detecte d the error will stop operation and other led driver will conduct normal operation. ? led gnd_short protection function w hen any led pin is gnd shorted the led pin becomes less than 0.20v and the pin is latched because of led_open detection. a fter that , the led pin is pull upped by inner supply but it continues less than 0.2v state in gran d shorted. after detecting timer of open state, if the grand shorted (open) state continues 2 7 counts all systems are latched. to prevent the miss detection there is 4 count interval of mask before starting the timer count. if pwm=h time is pwm=h time < 4count ??? not detect protection because it is in interval time pwm=h time > 4count ??? detect protection because it is out of interval time please verify enough to operate narrow pwm. led_gnd htssop- b28:21pin / hsop - m28 14pin the led_gnd pin is a power ground pin used for the led driver block . uvlo htssop- b28:25pin / hsop - m28 18pin this pin is used to for step - up dc/dc converter . when uvlo pin voltage reaches 3.0v (typ.) or more, ic will initiate step - up operation. if it reaches 2.7v (typ. ) or less, the ic will stop the step -up operation . the uvlo pin is of the high impedance type and involves no pull - down resistor, resulting in unstable potential in the open- circuited state . to avoid this problem, be sure to make input voltage setting with the use of a resistive divider or otherwise . for calculation examples, refer to information in ? 3. 1 app lication explanation / uvlo setting procedure ? lsp htssop- b28:26pin / hsop - m28 19pin the s etting pin for detection voltage of led short circuit protection . the led short circuit detection voltage is set to 9v (typ.) with the lsp pin being in the open - circuited state. however, making a change to the lsp pin input voltage will allow the threshold for led short circuit protection to be changed . the relation between the lsp pin voltage and the led short circuit protection detection voltage is given by the following equation . here led short led detecti on voltage vlsp lsp setting voltage lsp pin input voltage setting should be made in the range of 0.3v to 2.5v. for setting example, refer to information in ? 3. 1 application explanation/ lsp setting procedure ? ][ 10 v vled vlsp short short = ledx clk fail 1 2 3 4 1 2 2 16 9v interval of mask t imer count fig ure 14. timing chart of timer count 11 / 35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV stb (htssop- b28:27pin / hsop - m28 20pin the p in is used to on/off the ic and allowed for use to reset the ic from shutdown . the ic state is switched between on and off state according to voltages input in the stb pin. avoid using the stb pin between two states (0.8 to 2.0v) . input sequence of stb/pwm for startup , please input pwm before stb or at the same timing . while in shutdown mode, the timer keeps counting until the ic is completely shut down. for details of shutdown operation, refer to information in ? 3.1 application explanation/ the setting of r eg58 capacity and shutdown procedure ' vcc htssop- b28:28pin / hsop - m28 21pin ic power supply pin. input range is 9~35v. vcc pin voltage reaches 7.5v (typ.) or more, the ic will initiate operation. if it reaches 7.2v (typ.) or less, ic will be shut down. reg58 htssop-b28:1pin / hsop - m28 22pin the reg pin is used in the dc/dc converter driver block to output 5.8v voltage. the maximum operating current is 15ma.using the reg pin at a current higher than 15ma can affect the n pin output pulse, causing the ic to malfunction and leading to heat generation of the ic itself. to avoid this problem, it is recommended to make load setting to the minimum level . in addition, the reg58 pin is also allowed for use as discharge timer for dc/dc output capacitance . for details, refer to information in ? 3.1 application explanation/ the setting of reg58 capacity and shutdown procedure ' cs htssop- b28:2pin / hsop - m28 23pin the cs pin has the following two functions. dc/dc current mode current feed back function current flowing through the inductor is converted into voltage by the current sensing resistor rcs which connected to cs pin and this voltage is compared with voltage set with the error amplifier to control the dc/dc output voltage. 2 inductor current limit function (ocp pin) the cs pin also incorporates the overcurrent protection (ocp) function. if the cs pin voltage reaches 0.4v (typ.) or more, switching operation will be forcedly stopped. for detailed explanation, please refer to information in ?3.2 selection of dc/dc components - ocp setting procedure / dc/dc component current tolerance selection procedure?. n htssop- b28:3pi n / hsop - m28 24pin the n pin is used to output power to the external nmos gate driver for the dc/dc converter in the amplitude range of approximately 0 to 5.8v.frequency setting can be adjusted by a resistor connected to the rt pin. for details of frequen cy setting, refer to t he description of the rt pin. dcdc_gnd htssop- b28:4pin / hsop - m28 25pin the dcdc_gnd pin is a power ground pin for the driver block of the output pin n. rt htssop- b28:5pin / hsop - m28 26pin the rt pin is used to connect a dc/dc frequency setting resistor. dc/dc drive frequency is determined by connecting the rt resistor. ? relationship between drive frequency and rt resistance (ideal) however, drive frequency setting is limited in the range of 100 khz to 500khz. for calculation, refer to information in ? 3.1 application explanation/ dc/dc converter drive frequency setting ? when it reaches under vrt0.90v(typ), dcdc operation will be stopped in order to prevent from high speed oscillation when the rt resistance is shorted to gn d . and when rt pin returns to normal state, dcdc also returns to operation. fb htssop- b28:6pin / hsop - m28 27pin the fb pin is an output of dc/dc current mode error amplifier. fb pin detects the voltages of led pins (1 to 6) and controls inductor current so that the pin voltage of the led located in the row with the highest vf w ill come to 0.45v(130ma, typ.). therefore, the pin voltages of other leds will become higher by vf variation . fb voltage keep internal ic with pwm=low timing, and it can hold by using copied fb voltage while pwm=low. the fb keep voltage range is 0~4v, 40st eps for setting example, refer to information in ? 3.1 application explanation/ t he necessity for holding output voltage and fb voltage while pwm=low ? ss htssop- b28:7pin / hsop - m28 28pin soft start time and duty for soft start setting pin . the ss pin n ormally sources 2.0ua (typ.) of current. the ic has a built - in soft start start - up circuit independent of pwm light modulation , and the reby raises fb voltage as ss pin voltage rises independent of the duty cycle range of pwm light modulation . when the ss p in voltage reaches 3.7v (typ.), soft start operation will be completed to unmask the led protection function . for setting example, refer to information in ? 3.1 a pplication explanation/ s tart - up and ss capacity setting explanation ? ][ ][ 15000 ? = k khz f r sw rt 12/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV ss reg58 css[f] iss[a] 4.7v vss ? fb output current = source only v v vreg58[v] vss 3. application of bd9470 aefv ? bd9470afm 3.1 BD9470AEFV ? bd9470afm examination for application start - up and ss capacity setting explanation this section described the start -up sequence of this ic. description of start - up sequence stb=pwm=on system is on.ss starts to cha rge. at this time, a circuit in which ss voltage for slow start is equal to fb voltage regardless of whether the pwm pin is set to low or high level . since the fb pin and ss pin reach the lower limit of the internal sawtooth wave, the dc/dc converter oper ates and vout voltage rising . until it reachs a certain voltage even pwm=low by vlotage maintenance function. for detailed ovp maintanence function, please refer to?vout(ovp) maintanence function section?. vout voltage continues rising to reach a volta ge at which led current starts flowing . when the led current reaches the set amount of current, isolate the fb circuit from the ss circuit. with this, the start - up operation is completed . fast start -up is also diasabled by vout maintanence function afte r that, conduct normal operation following the feedback operation sequence with the led pins . if the ss pin voltage reaches 3.7v or more, the led protection function will be activated to forcedly end the ss and fbequalizing circuit . ss capacity settin g method b oot system as above described , because of start -up in the state of fb=ss, the start -up time can be imaged of the time to reach the point from the feedback voltage fb from stb = on . if you ss> 4.9v, fb output current mode will beco me source mode operation . if the feedback voltage of fb is the same as vss and the time can be calculated as below. ][ ][2 ][][ sec a v vfb fc t ss ss = fig ure 15. timing chart of start - up fig ure 16. ss setting procedure in fb source mode stb ss slope pwm n vout iled led_ok fb osc led_ok ss=fb circuit ss fb 5v 0.3 0.519v led_driver osc driver comp n led vout iled pwm pwm=l:stop 2ua ss slope d q pwm css ovp keep ovp stop/act led_ok time vss, vfb[v] ss=fb finished start up vss>4.9v fb=source mode 4.9v 13/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV ss reg58 r1[ohm] r 2[ohm] css[f] iss[a] v vss v vreg58[v] 3.9v vss 4.4v ?fb output current = sink & source mode however, if ss is set too short, inductor rush current will occur during start - up.in addition, if ss time is set too long, will result in the brighter in stages.ss capacity will veries with various factors, such as voltagestep -up ratio, dcdc driver frequency, led current and output output condencer, so it is recommended to test and confirm on the actual system. ss capacity is often set at about 0.047uf 0.47uf approximately as a reference value setting example ss time when the start -up is complete and css = 0.1uf, iss = 2ua, vss = 3.7v will be calculated as follows . in addition, when fb output is operated in sink/source mode refer to ?fb pin output current setting for detailed explanation. , ss voltage can be set to be in the range of 3.9v 4.4v at the ss pin voltage resistor divider . soft - start time will be set in that case is as follows . setting example when r1=200kohm, r2=470kohm, css=1.0uf, vreg58=5 .8v, iss=2ua, vss=3.7v, ss time is set as below ]sec[ 185 .0 ]a[e2 ]v[7.3]f[e1.0 t 6 6 ss = = ? ? ][ ][ ln sec b vvssa a t ss ? ? ? ? ? ? ??= 1 1 ][][ ][ ][ ][][][ ][][ f css aiss ohm r vvreg b ohm r ohm rf css ohm r ohm r a ? ? ? ? ? ? ? ? + = + = 1 58 2 1 2 1 ]sec[ 266 .0 31 7.3 12 .7 1 ln 12 .7 1 t ss = ? ? ? ? ? ? ? ?= fig ure 17. ss setting procedure in fb sink/ source mode time vss, vfb[v] ss=fb finished start up 3.9v b d9470afm ? BD9470AEFV the setting of reg58 capacity and shutdown procedure vout discharge function is built -in this ic when ic is shutdowned, the below decribes the opera tion sequence. explanation of shutdown sequence set stb pin to ?off? will stops dc/dc converter and reg58 , but led driver will remain operation . reset signal is output 1us extent to reset the latch on the ic at this time . therefore, undershooting will be generated on led current , but 1us is very short will not affect the brightness . di scharge the reg58 pin voltage from 5.8v to 2.4v with ? 5ua current . the vout voltage will be fully discharged with iled current and the iled current will no longer flow. when reg58pin voltage will reach 2.4v (typ.) or less to shut down all systems reg58 capacitance setting procedure the shutdown time ?t off ? can be calaulated by the following equation. the longest vout discharge time will be obtained w hen the pwm duty cycle is set to the minimum v o u t. make reg capacitance setting with an adequate margin so that systems will be shut off after vout voltage is fully discharged. ][ ][ ][.][ sec ua vfc t reg off 5 43 = fig ure 18. timing chart of shutdown 2.4v stb vout n reg50 pwm iled led_driver driver n led vout iled pwm pwm=l:stop cs reg58 5ua stb on->off reg58 2.4v/2.5v all shutdown c reg 1us pulse all shutdown 15/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV vcc vin rvcc v i_in reg58 + - rreg ireg dcdc driver n i_n ic block icc idcdc vcc series resistance setting procedure by inserting a series resistor to vcc will has the following affection . reduce the voltage vcc, and it is possible to suppress the heat generation of ic . iccvin is power consumption of ic possible to raise the surge ability to vcc. however, if resistance is set too large, it is neede d to consider that will result in vcc become vcc<9v minimum operation voltage .so the appropriate series resistance setting is needed . the current influx of ic i_in as shown on the right is ? circuit current of ic?icc ? current to load is connected toreg58? ireg ? current which used to drive dcdc fet?idcdc there are 3 paths within ic and the v of rvcc can be decided. vcc voltage generated by the relation as above described at that time c an be represented as below . the criterion of 9v is the minimum operating limit of the ic . when a series resistance is considered, please set with a sufficient margin . setting example above equation can be transformed as below. in typical operation, vin=24v, icc=5.5ma, rreg=10k, idcdc=2ma can be assumed and the vcc voltage is however, the result is in typical operation and the variability and margin is not considered. if the variability of vin=24v( -20% ,icc=8.5 a,rreg=10k( -5% ,reg58=5.8v(+5%),idcdc=2ma(+100%),vcc operation limit voltage9v(+20%) are assumed: according to above result, set rvcc = 640 or less is adequate on actual application . when a series resistance is considered, please set with a sufficient margin . ( ) ][9][][][][][][][ vv rvcc a ireg a idcdc aiccvvinvvcc >? + +?= ][][][ ][9][ ][ a ireg a idcdc aicc vvvin rvcc + + ? b d9470afm ? BD9470AEFV - + gmamp l h fb led1 pwm signal l h holding fb vol. block fb in fb copy - led2 - l h l h 100pf2200pf the necessity for holding output voltage and fb voltage while pwm= low in conventional control method, dcdc will be stopped and fb voltage become high impendence while p wm=low . however, if pwm=0% is continued to inputted to system, output voltage and fb voltage is reduced because of discharge phenomenon . eventually output voltage is equal to vin, and fb voltage drop to 0v . there are several problems such as the following listed if pwm dimming signal is tried to light -up a system . slow start cannot be controlled resulting in the fb voltage overshoot and rush current flow to inductor. flash phenomenon occur due to start -up control does not work . because there is a need to re - boost, take a long time to light up . in this ic, the pro blems as above mentioned is resolved by coping output voltage and fb voltage to ic internally at a time of pwm from high to low. the below describes fb and vout voltage holding function in detail. explanation of fb voltage holding function while pwm=low fb holding function means fb voltage will be copy to ic internally at a time of pwm from high to low, fb voltage will be maintained even in the period of pwm=low. because fb voltage resolution is split by 40 from 4v , so the voltage can be copied to ic in ternally in 0.1v step . in addition, fb pin voltage will be influenced by dcdc operation, the copied have 0.1v difference problem. but because fb voltage is returned as feedback voltage immediately and will not cause an operational problem while pwm=h, it is recommended to add about 100pf 2200pf to fb pin for noise reduction. fig ure 20. block diagram of keep_fb 17/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV pwm=high, normal feedback operation by led pin fb voltage is copied to ic at a time of pwm from high to low. fb voltage will be co pied by less than 1bit. for example when fb=2.16v, fb copy voltage is 2.1v. gmamp is works as buffer with while pw m=low, fb voltage is discharged to fb copy voltage. fb copy=fb voltage. fb copy=fb voltage and maintain. if pwm=0% and because follow the state continuously , fb voltage will not dropped by natural discharge. notice fb voltage holding function is performed at 0.1v step. if pwm signal is in low duty, fb voltage is not able to rise sufficiently when fb series resistance is small causing to rfbifb(typ.100ua) 0.1v(typ.), the output voltage may not be boosted up to the set voltage . therefore, it is recommended to set rfb > 2kohm so that v = rfb ifb> 0.2v . fig ure 21. timing chart of keep_fb fig ure 22. voltage to fb resistor pwm fb copy fb fb ifb(100ua typ) rfb cfb Sv=rfbifb>0.2v 18/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV vin cs dcdc_gnd n led1-6 vcc ovp vout ovp_in ovp copy - + ovp comp pwm signal - icomp + slope ss + fb control logic driver + holding ovp vol. block h : dcdc on l : dcdc off led_ok explanation of v out ovp voltage holding function when pwm=low ovp holding function means vout(ovp) voltage will be copy to ic internally at a time of pwm from high to low, voltage will be maintained even in the period of pw m=low. in addition to measures of the above problems , by applying this f unction, the high - speed start -up can be achieved without depending on the pwm . because vout voltage resolution is the same as fb holding function which is split by 40 from 4v ,so the voltage can be copied to ic internally in 0.1v step . the description of ov p holding function is divided into narrow pwm operation and start -up operation . explanation of ovp holding function at start - up in order to launch high speed start -up without depending on the pwm duty, ovp holding function will behave like the following descriptions . pwm=high, normal boost operation. ovp voltage is copied into ic when pwm is from high to low.ovp voltage will be copied upper 1bit at this time. for example: if ovp=2.43v, the copied voltage is 2.5v in ic. th e copied ovp voltage will be compared with ovp pin voltage internal ly, if ovp_copy>ovp, dcd c is operated. in other words, it is possible to achieve fast start -up by letting the voltage on the 1bit boosted up in the interval of pwm = low . wh en ovp_copy b d9470afm ? BD9470AEFV explanation of ovp holding function in narrow pwm duty dcdc operates only in the duration of pwm=high while narrow pwm is inputted, output voltage drops when pwm=0%. but, dcdc is operated by coping voltage even if pwm=low duration in this ic and output voltage will not drops. pwm=high, normal operation. ovp volta ge is copied into ic when pwm is from high to low.ovp voltage will be copied under 1bit at this time. for example: if ovp=2.43v, the copied voltage is 2.4v in ic. vout is discharged by ovp resistance. when copied ovp_copy ovp pin voltage, dcdc is operated, when ovp_copy ovp voltage, dcdc is stops. when operates in pwm=0%, the point will be repeated and repeated, so the output voltage will not drops naturally. condition of copy ovp voltage the copied ovp pin voltage as above explanation, it has upper a nd lower 1bit difference according to below condition. conditions of copy upper 1bit from startup to completion of step -up ovp de tection state conditions of copy lower 1bit normal operation state ( ovp undetected state ) the reason about why copy the voltage of upper 1bit when ovp is detected when ovp is detected by ovp=3v and stops dcdc operation. after that while pwm=low and if copy lower 1bit voltage will results in ovp=2.9v and release ovp detection function, therefore it is designed to copy upper 1bit when ovp is detected. fig ure 25. timin g chart 2 of keep _ovp pwm ovp copy ovp n 20/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV pwm5 pwm6 pwm4 pwm2 pwm3 pwm1 pgnd rcs cs n ovp led1 led2 led3 led4 led5 led6 fb cfb rfb fb current source mode ? sink/source mode the output of gmamp is constant current control in normal operation ans output anout100ua(typ.) in this ic. but, when pwm scanning operation and local dimming is performed, total led current and output voltage will different by each timming and fb feedback voltage.the below describes the this operation. as above shown,short pwm1,2,3 ans pwm4,5,6, assumed that scanning operation is performed. at this time, the sequence is described as b elow. when pwm4,5,6=highlow, fb voltage, vout ovp voltage is copied copied voltage is hold. when pwm1,2,3=high again, normal dcdc operation when pwm4,5,6=high again, led current increase. because led current increase resulting in fb voltage change.it take a long transition time because fb source current is 100ua at this time , therefore fb voltage is not insufficient and output voltage and led current will drop. fb voltage reaches the feedback voltage and led current and output voltage will operate no rmally. in ot her words, iled current drops at the point , this may be due to the transition time of the behavior that fb current sink first and then charge again . fig ure 26. timing chart of fb sink/source mode pwm 1,2,3 pwm 4,5,6 fb iled vout 21/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV therefore, in order to solve this problem in this ic, equipped with a mode of ?fb current only source 0ua +100ua?as a countermeasure to reduce the led current drop problem . ?fb source mode?is described as below. when pwm4,5,6=highlow, fb voltage, vout ovp voltage is copied copied voltage is hold. when pwm1,2,3 =high again, normal dcdc operation.but, fb voltage is larger than feedback voltage, and vout setting voltage also higher. when pwm4,5,6=high, led current increases. although led current is increased but the fb voltage has reached the feedback voltage and will not change at this time.therefore, there is no transition and v o u t, led current will not drop. led current and output voltage is operate normally when pwm1,2,3=low, led current reduces.but, fb is only has source ability , fb voltage is maintained c ontinuely but, despite the decreasing of led current, output voltage is increases because fb voltage is not changed. a ccording to above operation, the led undershoot problem cab be prevented by fb source mode. however , the above description is a simplif ied explanation for behavior , because the actual behavior of a waveform is different from the above, please check on the actual system . when fb source mode is used , care must be taken to the following contents . because it can be held at a higher voltage than normal fb voltage , output voltage may be higher . therefore , please note that the heat might be higher than pwm = 100% while scanning operation is performed . fig ure 27. timing chart of fb source mode pwm 1,2,3 pwm 4,5,6 fb ile d vout 22/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV led current setting setting of led output current ?iled? can be made by connecting a r esistor riset to the iset pin. riset and iled current setting equation however, led current setting should be made in the range of 40ma to 15 0ma. and the setting of ise t resistor is bellow at using 15 0ma to 250ma. iled(ma) 150 160 170 180 190 200 210 220 230 240 250 rset(kohm) 20.00 18.80 17.72 16.76 15.90 15.12 14.42 13.78 13.19 12.66 12.16 setting example to set iled current to 100ma, riset resistance is given by the following equation dc/dc converter drive frequency setting dc/dc converter drive frequency is determined by making rt resistance setting. drive frequency vs. rt resistance (ideal) equation setting example to set dc/dc drive frequency ?fsw? to 200 khz, rrt is given by the following equation and , the drive frequency setting range is 100khz 500khz. ][ ][ 3000 ? = k ma i r led iset ][30 ][100 3000 ][ 3000 ?= = = k ma ma i r led iset ][ ][ 15000 ? = k khz f r sw rt ][75 ][200 15000 ][ 15000 ?= = = k khz khz f r sw rt this equation has become an ideal equation without any correction item included. for accurate frequency settings, thorough verification should be performed on practical sets. here fsw = dc/dc converter oscillation fr equency [khz] ][)][(2653 9753.0 ? = ? k ma i r led iset 23/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV uvlo setting procedure uvlo pin for step - up dc/dc power supply. if the uvlo pin voltage reaches 3.0v (typ.) or more, the ic will start step -up operation. if it reaches 2.7v (typ.) or less, the ic wil l stop the step - up operation. uvlo pin is the high impedance type and no pull - down resistor inside, resulting in unstable potential in the open - circuit state. to avoid this problem, be sure to set input voltage with the use of a resistive divider . while th e vin voltage to be detected is set by the use of resistive dividers r1 and r2 as described below, resistance setting will be made by the following equation. uvlo setting procedure assume that vin is reduced and detected, uvlo is ?vin det? , r1 and r2 se tting will be made by the following equation: uvlo release voltage setting equation when r1 and r2 setting is determined by the equation shown above, uvlo release voltage will be given by the following equation. s ettin g example assuming that the normal vin operating voltage is 24v, uvlo detection voltage is 18v, and r2 resistance is 30k, r1 resistance setting is made by the following equation and, when uvlo release voltage vin can setting is made with r1 and r2, it will be given by the following equation to select dc/dc components, give consideration to ic variations as well as individual component variations, and then conduct thorough verification on actual systems. ][ ] [7.2 ])[7.2][( ][21 ? ? ?= k v vvv in krr det ][ ][2 ])[2][1( 0.3 v kr krkr v vin can ? ?+? = uvlo cuvlo vin r2 r1 2.7v/3.0v + - on/off ][170 ][7.2 ])[7.2][18( ][30 ][7.2 ])[7.2][( ][21 ?= ? ?= ? ?= k v vv k v vvvin krr det ][20][ ][30 ][170][30 ][0.3 ][2 ])[2][1( ][0.3 vv k kk v kr krkr v vin can = ? ?+? = ? ?+? = fig ure 28. block diagram of uvlo 24/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV ovp/scp setting method the ovp pin is an input pin for overvoltage protection and short circuit protection of dc/dc output voltage . the ovp pin is a high impedance type and no pull - down resistor inside, resulting in unstable potential in the open circuit state. to avoid this problem, be sure to make input voltage setting with the use of a resistive divider . conditions for each ovp protections are as listed in the table below. protection name protection pin detection c ondition release c ondition timer o peration protection type fail pin ovp timer set / ovp cancel ovp ovp> 2.9 v ovp<2.9v yes all latch gnd ovp detect / dcdc stop ovp ovp>3.0v ovp< 3.0 v no only dcdc converter stops during detection open scp ovp ovp<0.1v ovp>0.1v yes all latch gnd the following describes the setting procedu res of that vout pin voltage to be detected is set by the use of resistive dividers r1 and r2 as shown in the circuit diagram below. ovp detection setting method assuming that a voltage causing vout to abnormally rise and detecting ovp is ?vovp det? , r1 and r2 setting will be made by the following equation. timer set ? ovp release setting equation when r1 and r2 setting is determined by the equation shown above, ovp release voltage vovp can will be given by the following equation: scp detection equation when r1 and r2 setting is determined by the equation shown above, scp setting voltage vscp det will be given by the following equation . setting example assuming that normal vout voltage is 40v, ovp detection voltage vovp det is 48v, an d r2 resistance is 10k, r1 resistance is calculated by the following equation when ovp release voltage vovp can setting is made with the said r1 and r2, it will be given by the following equation s cp detection voltage is given by the following eq uation give consideration to ic variations as well as individual component variations, and then evaluate on actual systems. ][ ][0.3 ])[0.3][( ][21 : u: k v vv vovp krr det ][150 ][3 ])[3][48( ][10 ][0.3 ])[0.3][( ][21 : u: u: k v vv k v vv vovp krr det ][4.46][ ][10 ][150][10 ][9.2 ][2 ])[2][1( ][9.2 v v k kk v kr krkr v vovp can : :: u : :: u ][6.1][ ][10 ][150][10 ][1.0 ][2 ])[2][1( ][1.0 v v k kk v kr krkr v vscp det : :: u : :: u fig ure 29. ovp block diagram d q + - + - + - ovp dcdc_stop_comp ovp_timer_comp scp_timer_comp vout driver n cp timer 65536 cp timer 655368 3.0v 2.9v h:stop l:act 0.1v r1 r2 ][ ][2 ])[2][1( 9.2 v kr krkr v vovp can : :: u ][ ][2 ])[2][1( 1.0 v kr krkr v vscp det : :: u 25/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV + - lsp clsp reg58=5.8v r1 r2 r3= 3100k r4 900k ref=4v ledx 900k 100k lsp setting procedure led short threshold voltage can be adjusted by setting lsp pin voltage. led short detection voltage is set to 9v when lsp pin=open state. please set input voltage of lsp pin from 0 .3v~2.5v range. the relation between lsp pins and led short protection voltage as below. also, lsp pin divides 4v within the ic using resistive dividers (see the circuit dia gram shown below) therefore, connecting an external resistor to the lsp pin will produce resistance combined with the internal ic resistance. consequently, lsp pin voltage setting using external resistive dividers, it is recommended to connect them having resistance little affected by the internal resistance. ( smaller resistance have less influence on internal resistance, but will result in larger power consumption. ) lsp detection voltage setting if the setting of lsp detection voltage vlsp is made by dividing the reg58v voltage by the use of resistive dividers r1and r2, vlsp will be given by the following equation . however, this equation includes no internal ic resistance. if internal resistance is taken into account, detection vol tage vlsp will be given by the following equation. make setting of r1 and r2 resistance so that a difference between resistance values found by equations (1) and (2) will come to approximately 2% or less as a guide. s etting example assuming that ls p is approximated by equation (1) in order to set lsp detection voltage to 5v, r1 comes to 53k ? andr2 comes to 5k ? .lsp detection voltage taking into account internal ic resistance by equation (2), it will be given as the difference is given as: as a result, this setting will be little affected by internal impedance. )1(][10 ][2][1( ][2 ][58 ? v krkr kr v reg vlsp ? ? ? ? ? ? ? ? ?+? ? = ( ) ( ) ( ) )2(][10 ][3][1][4][242][3][1( ][1][3][58][4][2 ? v krkrkrkrrrkrkr krv ref rv reg krkr vlsp ? ? ? ? ? ? ? ? ?+???++?? ?+ ?? = ( ) ( ) ( ) ][033.510 ][3100][53][900][5][900][5][3100][53( ][53][4][3100][8.5][900][5 vv k kkkkkk k kvkvkk vlsp = ? ? ? ? ? ? ? ? ?+???+?+??? ?+??? = ( ) %66.0100][5/][5][033.5 = ? vvv ][ 10 v vled vlsp short short ? = f ig ure 30. lsp block diagram 26/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 n 15 n 001
b d9470afm ? BD9470AEFV 1 2 cp count up start led1_voltage 0.8v 12v oscllator (internal ic) cp counter 0v led1 short pro. detect i_led1 current fail (open) low 3 65535 65536 65534 cp count up end led1 latch up fail det timer latch function this ic has a built -in timer latch counter to make setting of timer latch time by counting a clock frequency set with the rt pin. timer latch time the timer latch counter begins counting from the timing when any abnormal state is detected. the timer will be latched after a lapse of a period of time given by the following equation. if the abnormal state continues even when pwm is set to low level, the counter will not reset counting. here latch time = a period of time, which the timer is latched r rt =rt pin connecting resistance protection time which described above is applied for led pin open protection, led pin short protection, scp protection. the protec tion of fb overshoot and ovp protection as below: c lock oscillation of timer latch uses dcdc clock. so timer latch time depend on unevenness of dcdc oscillation. in 150khz, timer latch time is 5% unevenness. setting example in led_open protection, led_short protection, scp protection, when rt resistance=100kohm, the timer latch time is and, fb overshoot protection, ovp protection is ][ 105.1 ][ 65536 105.1 2 7 10 16 s kr r latch rt rt time ? = = ][437.0 105.1 ][100 65536 105.1 ][ 65536 7 7 s k kr latch rt time = ? = ? = ][ . ][ . s kr r latch rt rt time 7 10 18 1051 262144 1051 2 ? = = ][. . ][ . ][ s k kr latch rt time 751 1051 100 262144 1051 524288 7 7 = ? = ? = fig ure 31. timing chart of lsp time latch 27/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV 3.2 selection of dcdc components ocp setting procedure/dcdc component c urrent tolerance selection procedure the ocp detection function that is one of the functions of the cs pin will stop the dc/dc converter operating if the cs pin voltage becomes greater than 0.4v. consequently, it is needed to calculate a peak current flowi ng through the coill and then review the resistance of rcs. furthermore, a current tolerance for dc/dc components should be larger than that for peak current flowing through the coil l. the following section describes the peak coil current calculation proc edure, cs pin connection resistor rcs selection procedure, and dc/dc component current tolerance selection procedure calculation of coil current ipeak ripple voltage generated at the cs pin is determined by conditions for dc/dc application components. a ssuming the conditions: output voltage=vout [v] led total current=iout [a] dcdc input voltage=vin [v] dcdc efficiency= [%] mean input current iin required for the whole system is given by the following equation further, according to drive operation with the dc/dc converter switching frequency fsw [hz], inductor ripple current il [a] generated at the inductor l is given by the following equation. as a result, the peak current ipeak of il is given by the following equation. c s pin connection resistor rcs selection procedure the current ipeak flows into rcs to generate voltage.(see timing chart shown to the right.) the voltage vcspeak is given by the following equation. if this vcspeak voltage reaches 0.4v, dc/dc output will stop. con sequently, to select rcs resistance, the following condition should be met. dcdc component current tolerance selection procedure iocp current needed for ocp detection voltage cs to reach 0.4v is given by the following equation the relation amon g ipeak current (equation (1)), iocp current (equation (2)), dc/dc application components including f e ts , inductors, and diodes should be selected so that the equation shown above will be met. furthermore, it is recommended to normally use dc/dc ap plication components in continuous mode. assuming that the lower limit value of coil ripple current is imin, the following equation should be met a failure to meet this condition is referred to as discontinuous mode. ][ [%]][ ][][ a vv aivv i in out out in = ][ ][][][ ][])[][( a hz fvvhl vvvvvv il sw out in in out ? = )1(][ 2 ][ ][ a ail aiipeak in ? += ][ vipeak rcs vcs peak = << ocp peak ii max. current tolerance for compone nt ][4.0][][ vaipeak rcs < ? vin vout n cs dcdc_gnd rcs il l iout(total) fsw iin ba) (t) 0.5v (t) bv) (v) vcs[v] il[a] <1il (t) n[v] ipeak imin vcspeak )2(][ ][ ][4.0 a rcs v i ocp ? = 0][ 2 ][ ][im > ? ?= a ail ai in in fig ure32. dcdc application diagram and coil current 28/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV setting example output voltage=vou t [v]=40v led total current=iout [a]=120ma6ch=0.72a dcdc input voltage=vin [v]=24v dcdc efficiency=[%]=90% mean input current iin required for the whole system is given by the following equation dcdc switching frequency=fsw[hz]=200khz inductor l[h] =47h the inductor ripple currentil[a] is: as a result, the il peak current ipeak is: when rcs resistance is set to 0.15ohm, the vcs peak voltage will be given by the following equation consequently, the result meets the condition. fu rthermore, i ocp current at which ocp is detected is given by the following equation if the current tolerance for components to be used (e.g. fets, inductors, diodes) is smaller than 2.5a, as a result, since the condition above is met, the selection of components is accepted . and, the lower limit of il ripple current imin is: the system will not be put into discontinuous mode. to select dc/dc components, please consider ic variations as well as individual component variations, andthen conduct thorough verification on practical systems. ][33.1 [%]90][24 ][72.0][40 [%]][ ][][ ][ a v av vv aivv ai in out out in = = = ][02.1 ][10200][40][1047 ][24])[24][40( ][][][ ][])[][( 3 6 a hz vh vvv hz fvvhl vvvvvv il sw out in in out = ? = ? = ? ][84.1 2 ][02.1 ][33.1][ 2 ][ ][ a a aa ail aiipeak in =+= ? += 0][82.0 2 ][02.1 ][33.1][ 2 ][ ][im >=?= ? ?= a a aa ail ai in in vva ipeak rcs vcs peak 5.0][276.0][84.1][15.0 < =?== ][67.2 ][15.0 ][4.0 a v i ocp = ? = ? result of peak current calculation ? result of review of rcs resistance << ocp peak ii max. current tolera nce for compone n t ? result of review of current tolerance for dc/dc components ][0.3][67.2][84.1 aaa <<= 29/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV i l selection of inductor the value of inductor has significant influence on the input ripple current. as shown by equation (1), the larger the inductor and the higher the switching frequency, the indu ctor ripple current ? il becomes increasingly lower . (1) ][ )( ????? a fvl vvv il sw out in in out uu u efficiency as shown by equation (2), peak input current is given as equation (3). here, l reactance value [h] v out dc/dc output voltage[v] v in input voltage[v] i out out put current(led total current)[a] i in input current[a] f sw oscillation frequency[hz] if a current in excess of the rated current of the inductor applies to the coil, the inductor will cause magnetic saturation, resulting in lower efficiency. select an inductor with an adequate margin so that peak current will not exceed the rated current of the inductor. to reduce power dissipation from and increase efficiency of induct or, select an inductor with low resistance component (dcr or ac r). sele ction of switching mosfet transistors there will be no problem for switching mosfet transistors having absolute maximum rating higher than rated current of the inductor l and vf higher than ?c out breakdown voltage rectifier diode?. however, to achieve hi gh- speed switching, select transistors with small gate capacity (injected charge amount). ? rated current larger than current protection setting current is recommended ? selecting transistors with low on resistance can obtain high efficiency. selection of rectifier diodes select current capability higher than the rated current of the inductor l and inverse breakdown voltage higher that c out break - down voltage, particularly having low forward voltage vf. v out v in c out r cs l i l (2) ????? inin out out iv iv u u k (3) 2 2 ????? il v iv il iil in out out in max u u k fig ure33. dcdc application circuit and coil current 30/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV 3.3 timing chart 7.5v stb 2.0v 0.8v vcc reg58 fail 2.6v 2.4v ( normal state ) iset rt ss 3.7v fb vout pwm iled ss=fb or led feed-back led_open led_short ovp scp led feed-back led_gnd_short iset_gnd_short uvlo reg58_uvlo vcc_uvlo 1.5v 0.8v 1.5v disaable disaable disaable disaable disaable disaable disaable disaable disaable disaable enable enable enable enable enable rt_gnd_short gnd fig ure 34. timing chart 31/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV 3. 4 list of protection fu nctions list of protection detecting condition protection names detection detection condition release condition timer protection type pin detection pin condition pwm ss led open led ledx < 0. 20v h ss>3.7v ledx > 0. 20v 2 16 count latch ( only detec ted ) ledshort led ledx > 9v h ss>3.7v ledx < 9v 2 16 count latch ( only detected ) (lsp=open) (lsp=open) led gnd short led ledx < 0. 20v h ss>3.7v ledx > 0. 20v 2 16 + 2 7 count latch iset gnd s hort iset under iset 90% canceled iset=gnd sta te immediately detect auto-restart rt gnd short rt under rt 90% - - canceled r t=gnd state immediately detect auto-restart uvlo uvlo uvlo<2.7v - - uvlo>3v immediately detect auto-restart reg58 uvlo reg58 reg58<2.4v - - reg58>2.6v immediately detect auto-restart vcc uvlo vcc vcc<7. 2v - - vcc>7.5v immediately detect auto-restart ovp ovp ovp>3.0v - - ovp<2.9v 2 18 count latch scp ovp ovp<0.1v - - ovp>0.1v 2 16 count latch ocp cs ocp>0.4v - - - immediately detect pulse- by - pulse * to clear the latch type, stb should be set to ?l? once, and then to ?h? * the count of timer means ? 1count = 1 duty of switching frequency. list of protection detecting operation protection functions operation when the hysteresis type protection is detected dc/dc led dri ver soft start fail pin led open continues operation only detected led stops operating after cp counting not discharged open after cp counting ledshort continues operation only detected led stops operating after cp counting not discharged open after cp counting led gndshort stops operating after cp counting stops operating after cp counting discharge open after cp counting iset gnd short instantaneously stops operating instantaneously stops operating not discharged open immediately rt gnd short insta ntaneously stops operating normal operation not discharged low stb instantaneously stops operating stops (and reg58<2.4v) discharge open immediately uvlo instantaneously stops operating instantaneously stops operating discharge open immediately reg58 uv lo instantaneously stops operating instantaneously stops operating discharge open immediately vcc uvlo instantaneously stops operating instantaneously stops operating discharge open immediately ovp stops operating after cp counting stops operating after cp counting discharge open after cp counting scp stops operating after cp counting stops operating after cp counting discharge open after cp counting ocp limits duty cycle continues operation not discharged low 32/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV 4. caution on use 1.) we pay utmost attention to the quality control of this product. however, if it exceeds the absolute maximum ratin gs including applied voltage and operating temperature range, it may lead to its deterioration or breakdown. furth er, this makes it impossible to assume a breakdow n state such as short or open circuit mode. if any special mod e to exceed the absolute maximum ratings is assumed, consider adding physical safety measures such as fuses. 2.) making a reverse connection of the power supply connector can cause the ic to break down. to protect the ic f orm breakdown due to reverse connection, take preventive measures such as inserting a diode between the exter nal power supply and the power supply pin of the ic. 3.) since current regenerated by back electromotive force flows back, take preventive measures such as inserting a c apacitor between the power supply and the ground as a path of the regenerative current and fully ensure that ca pacitance presents no problems with characteristics such as lack of capacitance of electrolytic capacit ors causes a t low temperatures, and then determine the power supply line. provide thermal design having an adequate margin in consideration of power dissipation (pd) in the practical operating conditions. 4.) the potential of the gnd pin should be maintained a t the minimum level in any operating state. 5.) provide thermal design having an adequate margin in consideration of power dissipation (pd) in the practical oper ating conditions. to mount the ic on a printed circuit board, pay utmost attention to the direction and displacement of the ic. furthermore, the ic may get damaged if it is mounted in an erroneous manner or if a short circuit is established due to foreign matters entered between output pins or between output pin and power supply gnd pin. 6.) note that using this ic in strong magnetic field may cause it to malfunction. 7.) please set the output tr not to over a bsolute maximum ratings and aso. cmos ic and plural power supply ic have a possible to flow lush current momentarily. please note vcc capacitor, vcc and gn d layout . 8.) this ic has a built - in thermal - protection circuit (tsd circuit ). the thermal - protection circuit (tsd circuit) is a circuit absolutely intended to protect the ic from thermal runaway, not intended to protect or guarantee the ic. consequently, do n ot use the ic based on the activation of this ts d circuit for subsequent continuous use and operation of the ic. 9.) when testing the ic on a set board with a capacitor connected to the pin, the ic can be subjected to stress. in this case, be sure to discharge the capacitor for each process. in addition, to connect the ic to a jig up to the t esting process, be sure to turn off the power supply prior to connection, and disconnect the jig only after turnin g off the power supply. 10.) this monolithic ic contains p + is olation and p substrate layers between adjacent elements in order to keep them isolated. p-n j unctions are formed at the intersections of these p layers and the n layers of other elements, thus making up different types of parasitic elements. for example, if a resistor and a transistor is connected with pins respectively as shown in fig. ? when gnd > (pin a) for the resistor, or when gnd > (pin b) for the transistor (npn), p-n junctions operate as a a parasitic diode. ? when gnd > (pin b) for the transistor (npn) , the parasitic npn transistor operates by the n layer of other element adjacent to the parasitic diode aforementioned. due to the structure of the ic, parasitic elements are inevitably formed depending on the relationships of potential. the operation of parasitic diodes can result in interferences in circuit operation, leading to malfunctions and eventually breakdown of the ic. consequently, pay utmost attention not to use the ic for any applications by which the parasitic elements are operated, such as applying a voltage lower than that of gnd (p substrate) to the input pin. status of this document the japanese version of this document is formal specification. a customer may use this translation version only for a reference to help reading the formal version. if there are any differences in translation version of this document formal version takes priority fig ure 35 . example of simple structure of monolithic ic b c e adjacent oth er elements parasitic (pin b) gnd parasitic element (pin a) parasitic element resistor p substrate n gnd p n p (pin a) p n transistor (npn) b parasitic element gnd e c gnd p p n n n p n p substrate (pin b) 33/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 n 15 n 001
b d9470afm ? BD9470AEFV ordering informatio n b d 9 4 7 0 a f m e 2 part number package fm : h sop -m packaging and forming specification e2: embossed tape and reel b d 9 4 7 0 a e f v e 2 part number package efv : htssop-b packaging and forming specification e2: embossed tape and reel physical dimension tape an d reel information 34/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
b d9470afm ? BD9470AEFV 6. revision history date revision changes 26 .oct .2012 001 new release 09.jan.2013 002 p6 / v erified minimum iset resistor 002 p10 / v erified iset terminal instruction 002 p23 / verified led current settin g 19.oct.2013 003 p2 / change pin con f iguration 003 p1 / delete pbfree, rohs 003 add notice 35/35 tsz02201 - 0f10c1002000 -1-2 ? 2013 rohm co., ltd. all rights reserved. 19.oct.2013 rev.003 www.rohm.com tsz22111 ? 15 ? 001
datasheet d a t a s h e e t notice - ge rev.002 ? 2014 rohm co., ltd. all rights reserved. notice precaution on using rohm products 1. our products are designed and manufac tured for application in ordinary elec tronic equipments (such as av equipment, oa equipment, telecommunication equipment, home electroni c appliances, amusement equipment, etc.). if you intend to use our products in devices requiring ex tremely high reliability (such as medical equipment (note 1) , transport equipment, traffic equipment, aircraft/spacecra ft, nuclear power controllers, fuel c ontrollers, car equipment including car accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or serious damage to property (?specific applications?), please consult with the rohm sale s representative in advance. unless otherwise agreed in writing by rohm in advance, ro hm shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any ro hm?s products for specific applications. (note1) medical equipment classification of the specific applications japan usa eu china class class class b class class class 2. rohm designs and manufactures its products subject to strict quality control system. however, semiconductor products can fail or malfunction at a certain rate. please be sure to implement, at your own responsibilities, adequate safety measures including but not limited to fail-safe desi gn against the physical injury, damage to any property, which a failure or malfunction of our products may cause. the following are examples of safety measures: [a] installation of protection circuits or other protective devices to improve system safety [b] installation of redundant circuits to reduce the impact of single or multiple circuit failure 3. our products are designed and manufactured for use under standard conditions and not under any special or extraordinary environments or conditio ns, as exemplified below. accordin gly, rohm shall not be in any way responsible or liable for any damages, expenses or losses arising from the use of an y rohm?s products under any special or extraordinary environments or conditions. if you intend to use our products under any special or extraordinary environments or conditions (as exemplified bel ow), your independent verification and confirmation of product performance, reliability, etc, prior to use, must be necessary: [a] use of our products in any types of liquid, incl uding water, oils, chemicals, and organic solvents [b] use of our products outdoors or in places where the products are exposed to direct sunlight or dust [c] use of our products in places where the products ar e exposed to sea wind or corrosive gases, including cl 2 , h 2 s, nh 3 , so 2 , and no 2 [d] use of our products in places where the products are exposed to static electricity or electromagnetic waves [e] use of our products in proximity to heat-producing components, plastic cords, or other flammable items [f] sealing or coating our products with resin or other coating materials [g] use of our products without cleaning residue of flux (ev en if you use no-clean type fluxes, cleaning residue of flux is recommended); or washing our products by using water or water-soluble cleaning agents for cleaning residue after soldering [h] use of the products in places subject to dew condensation 4. the products are not subjec t to radiation-proof design. 5. please verify and confirm characteristics of the final or mounted products in using the products. 6. in particular, if a transient load (a large amount of load applied in a short per iod of time, such as pulse. is applied, confirmation of performance characteristics after on-boar d mounting is strongly recomm ended. avoid applying power exceeding normal rated power; exceeding the power rating under steady-state loading c ondition may negatively affect product performance and reliability. 7. de-rate power dissipation (pd) depending on ambient temper ature (ta). when used in seal ed area, confirm the actual ambient temperature. 8. confirm that operation temperat ure is within the specified range descr ibed in the product specification. 9. rohm shall not be in any way responsible or liable for fa ilure induced under deviant condi tion from what is defined in this document. precaution for mounting / circuit board design 1. when a highly active halogenous (chlori ne, bromine, etc.) flux is used, the resi due of flux may negatively affect product performance and reliability. 2. in principle, the reflow soldering method must be used; if flow soldering met hod is preferred, please consult with the rohm representative in advance. for details, please refer to rohm mounting specification
datasheet d a t a s h e e t notice - ge rev.002 ? 2014 rohm co., ltd. all rights reserved. precautions regarding application examples and external circuits 1. if change is made to the constant of an external circuit, pl ease allow a sufficient margin c onsidering variations of the characteristics of the products and external components, including transient characteri stics, as well as static characteristics. 2. you agree that application notes, re ference designs, and associated data and in formation contained in this document are presented only as guidance for products use. theref ore, in case you use such information, you are solely responsible for it and you must exercise your own independent verification and judgment in the use of such information contained in this document. rohm shall not be in any way responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of such information. precaution for electrostatic this product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. please take proper caution in your manufacturing process and storage so that voltage exceeding t he products maximum rating will not be applied to products. please take special care under dry condit ion (e.g. grounding of human body / equipment / solder iron, isolation from charged objects, se tting of ionizer, friction prevention and temperature / humidity control). precaution for storage / transportation 1. product performance and soldered connections may deteriora te if the products are stor ed in the places where: [a] the products are exposed to sea winds or corros ive gases, including cl2, h2s, nh3, so2, and no2 [b] the temperature or humidity exceeds those recommended by rohm [c] the products are exposed to di rect sunshine or condensation [d] the products are exposed to high electrostatic 2. even under rohm recommended storage c ondition, solderability of products out of recommended storage time period may be degraded. it is strongly recommended to confirm sol derability before using products of which storage time is exceeding the recommended storage time period. 3. store / transport cartons in the co rrect direction, which is indicated on a carton with a symbol. otherwise bent leads may occur due to excessive stress applied when dropping of a carton. 4. use products within the specified time after opening a hum idity barrier bag. baking is required before using products of which storage time is exceeding the recommended storage time period. precaution for product label qr code printed on rohm products label is for rohm?s internal use only. precaution for disposition when disposing products please dispose them proper ly using an authorized industry waste company. precaution for foreign exchange and foreign trade act since our products might fall under cont rolled goods prescribed by the applicable foreign exchange and foreign trade act, please consult with rohm representative in case of export. precaution regarding intellectual property rights 1. all information and data including but not limited to application example contain ed in this document is for reference only. rohm does not warrant that foregoi ng information or data will not infringe any intellectual property rights or any other rights of any third party regarding such information or data. rohm shall not be in any way responsible or liable for infringement of any intellectual property rights or ot her damages arising from use of such information or data.: 2. no license, expressly or implied, is granted hereby under any intellectual property rights or other rights of rohm or any third parties with respect to the information contained in this document. other precaution 1. this document may not be reprinted or reproduced, in whol e or in part, without prior written consent of rohm. 2. the products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written consent of rohm. 3. in no event shall you use in any wa y whatsoever the products and the related technical information contained in the products or this document for any military purposes, incl uding but not limited to, the development of mass-destruction weapons. 4. the proper names of companies or products described in this document are trademarks or registered trademarks of rohm, its affiliated companies or third parties.
datasheet datasheet notice ? we rev.001 ? 2014 rohm co., ltd. all rights reserved. general precaution 1. before you use our pro ducts, you are requested to care fully read this document and fully understand its contents. rohm shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny rohms products against warning, caution or note contained in this document. 2. all information contained in this docume nt is current as of the issuing date and subj ec t to change without any prior notice. before purchasing or using rohms products, please confirm the la test information with a rohm sale s representative. 3. the information contained in this doc ument is provi ded on an as is basis and rohm does not warrant that all information contained in this document is accurate an d/or error-free. rohm shall not be in an y way responsible or liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccur acy or errors of or concerning such information.
datasheet part number BD9470AEFV package htssop-b28 unit quantity 2500 minimum package quantity 2500 packing type taping constitution materials list inquiry rohs yes BD9470AEFV - web page distribution inventory

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