View BL0100A_8754678.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

high efficiency for led backlight, 1ch led driver ic BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 1 apr. 04 , 2 01 4 general descriptions BL0100A is led driver ic for led backlight, and it can do dimming to 0.02 % by external pwm signal. this ic realizes a high efficiency by the boost convertor control that absorb s variability on v f . the product easily achieves high cost-performance led drive system with few external components and enhanced protection function s. features and benefit boost convertor current-mode type pwm control pwm frequency is 1 00 khz to 500khz maximum on duty is 90 % led current control pwm dimming analog dimming high contrast ratio is 1 / 5000 accuracy of reg output voltage is 2 % protection functions error signal output overcurrent protection for boost circuit (ocp) ------------------------------------------------- pulse- by -pulse overcurrent protection for led output (led_ocp) ------------------------------------------------- pulse- by -pulse overvoltage protection (ovp) -------------- auto restart output open/short protection --------------- auto restart thermal shutdown (tsd) -------------------- auto restart typical application circuit vcc vref pwm er fset reg comp gnd drv oc ovp sw ifb BL0100A tc_BL0100A_1_r1 package soic14 not to scale electrical characteristics ? absolute maximum voltage of vcc pin is 20 v ? adjustable pwm frequency, 100 khz to 500 khz applications ? led backlights ? led lighting etc. downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 2 apr. 04 , 2 01 4 contents general descriptions ----------------------------------------------------------------------- 1 1. absolute maximum ratings --------------------------------------------------------- 3 2. electrical characteristics ------------------------------------------------------------- 3 3. functional block diagram ----------------------------------------------------------- 5 4. pin list table --------------------------------------------------------------------------- 5 5. typical application circuit --------------------------------------------------------- 6 6. package diagram ---------------------------------------------------------------------- 7 7. marking diagram --------------------------------------------------------------------- 7 8. functional description --------------------------------------------------------------- 8 8.1 startup operation ------------------------------------------------------------ 8 8.2 constant current control operation ------------------------------------ 9 8.3 pwm dimming function --------------------------------------------------- 9 8.4 gate drive ---------------------------------------------------------------------- 9 8.5 protection function --------------------------------------------------------- 10 8.6 error signal output function -------------------------------------------- 13 9. design notes --------------------------------------------------------------------------- 14 9.1 peripheral components ---------------------------------------------------- 14 9.2 in ductor design parameters ----------------------------------------------- 14 9.3 pcd trace layout and component placement ----------------------- 14 10. reference design of power supply ----------------------------------------------- 16 operating precautions -------------------------------------------------------- 18 important notes ------------------------------------------------------------------- 19 downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 3 apr. 04 , 2 01 4 1. absolute maximum ratings ? the polarity value for current specifies a sink as "+ ," and a source as "? ," referencing the ic. ? unless otherwise specified, t a is 25 c parameter symbol test conditions pins rating unit reg pin source current i reg 2 ? 7 ? 1 ma ovp pin voltage v ovp 3 ? 7 ? 0 .3 5 v pwm pin voltage v pwm 4 ? 7 ? 0 .3 5 v ifb pin clamp current i fb s i n gl e p u l s e 5 s 12 ? 7 ? 10 ma fset pin source current i fset 6 ? 7 ? 300 a vcc pin voltage v cc 8 ? 7 ? 0 .3 20 v sw pin voltage v sw 9 ? 7 ? 0 .3 v cc + 0 .3 v drv pin voltage v drv 10 ? 7 ? 0 .3 v cc + 0 .3 v oc pin voltage v oc 11 ? 7 ? 0 .3 5 v er pin voltage v er 14 ? 7 ? 0 .3 v r e g v vref pin voltage v ref 1 ? 7 ? 0 .3 5 v operating ambient temperature t op ? ? 40 85 c storage temperature t stg ? ? 40 125 c junction temperature t j ? 150 c 2. electrical characteristics ? the polarity value for current specifies a sink as "+ ," and a source as "? ," referencing the ic. ? unless otherwise specified, t a is 25 c , v cc = 12 v parameter symbol test conditions pins min. typ. max. unit start / stop operation operation start voltage 1 v cc (on) 8 ? 7 8.5 9.6 10.5 v operation stop voltage v cc (o ff ) 8 ? 7 8.0 9.1 10.0 v circuit current in operation i cc (o n) 8 ? 7 ? 5.3 8.0 ma circuit current in non-operation i cc (o ff ) v cc = 8 v 8 ? 7 ? 70 200 a reg pin output voltage v reg 2 ? 7 4.9 5.0 5.1 v oscillation pwm operation frequency 1 f pwm1 v fset = 2 v 10 ? 7 95 100 105 khz pwm operation frequency 2 f pwm2 r22 = 4.7 k 10 ? 7 440 500 560 khz maximum on duty d max 10 ? 7 85 90 95 % minimum on time t min 10 ? 7 40 140 240 ns comp pin voltage at oscillation start v comp(on) 13 ? 7 0.35 0.50 0.65 v comp pin voltage at oscillation stop v comp(off) 13 ? 7 0.10 0.25 0.40 v vref / ifb pin vref pin minimum setting voltage v ref(min) v ref = 0 v 1 ? 7 0.05 0.25 0.45 v vref pin maximum setting voltage v ref(max) v ref = 5 v 1 ? 7 1.75 2.00 2.35 v 1 v cc(on) > v cc(off) downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 4 apr. 04 , 2 01 4 parameter symbol test conditions pins min. typ. max. unit ifb pin voltage at auto restart operation v ifb( ar ) v ref = 1 v 12 ? 7 0.45 0.50 0.55 v ifb pin voltage at comp charge switching v ifb(comp) v ref = 1 v 12 ? 7 0.55 0.60 0.65 v ifb pin overcurrent protection low threshold voltage v ifb(ocl) v ref = 1 v 12 ? 7 1.9 2.0 2.1 v ifb pin overcurrent protection release threshold voltage v ifb(ocl- off ) v ref = 1 v 12 ? 7 1.5 1.6 1.7 v ifb pin overcurrent protection high threshold voltage v ifb( och ) 12 ? 7 3.8 4.0 4.2 v ifb pin bias current i ifb(b) v ifb = 5 v 12 ? 7 ? ? 1 a current detection threshold voltage v ifb v ref = 1 v 12 ? 7 0.98 1.00 1.02 v comp pin comp pin maximum output voltage v comp (max) v ifb = 0.7 v 13 ? 7 4.8 5.0 ? v comp pin minimum output voltage v comp (min) v ifb = 2.0 v 13 ? 7 ? 0 0.2 v transconductance gm ? ? 640 ? s comp pin source current i c omp(src) v ifb = 0.7 v 13 ? 7 ? 77 ? 57 ? 37 a comp pin sink current i c omp(snk) v ifb = 1.5 v 13 ? 7 37 57 77 a comp pin charge current at startup i comp(s) v comp = 0 v 13 ? 7 ? 19 ? 11 ? 3 a comp pin reset current i c omp(r) 13 ? 7 200 360 520 a er pin er pin sink current during non-alarm i er v er = 1 v 14 ? 7 2.5 4.4 6.3 ma boost parts overcurrent protection (ocp) oc pin overcurrent protection threshold voltage v ocp v comp = 4.5 v 11 ? 7 0.57 0.60 0.63 v overvoltage protection (ovp) ovp pin overvoltage protection threshold voltage v ovp 3 ? 7 2.85 3.00 3.15 v ovp pin ovp release threshold voltage v ovp(off) 3 ? 7 2.60 2.75 2.90 v pwm pin pwm pin on threshold voltage v pwm(on) 4 ? 7 1.4 1.5 1.6 v pwm pin off threshold voltage v pwm(off) 4 ? 7 0.9 1.0 1.1 v pwm pin impedance r pwm 4 ? 7 100 200 300 k sw / drv pin sw pin source current i sw(src) 9 ? 7 ? ? 85 ? ma sw pin sink current i sw(snk) 9 ? 7 ? 220 ? ma drv pin source current i drv(src) 10 ? 7 ? ? 0.36 ? a drv pin sink current i drv(snk) 10 ? 7 ? 0.85 ? a thermal shutdown protection (tsd) thermal shutdown activating temperature t j(tsd) ? 125 ? ? c hysteresis temperature of tsd t j(tsd)hys ? ? 65 ? c thermal resistance thermal resistance from junction to ambient j-a ? ? ? 120 c /w downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 5 apr. 04 , 2 01 4 3. functional block diagram vcc uvlo reg on/off pwm osc main logic tsd auto restart protection oc control slope compensation feedback control abnormal detector overvoltage detector pwm pulse detector reg sw drv er oc gnd comp fb vref ovp fset pwm vcc vcc vcc 2 9 10 14 11 1 3 6 4 8 12 13 drive drive 7 bd_BL0100A_r1 4. pin list table 13 24 6 57 13 1412 vref ovp reg pwm fset (n.c .) gnd er ifb comp oc sw drv vcc 8 9 1110 number name function 1 vref detection voltage setting 2 reg internal regulator output 3 ovp overvoltage detection signal input 4 pwm dimming mosfet gate drive output 5 (n.c.) 6 fset boost mosfet drive frequency setting 7 gnd ground 8 vcc power supply voltage input 9 sw pwm dimming drive output 10 drv boost mosfet gate drive output 11 oc current mode control signal input and overcurrent protection signal input 12 ifb feedback signal input of current detection 13 comp phase compensation and soft-start setting 14 er error signal output downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 6 apr. 04 , 2 01 4 5. typical application circuit f1 vcc sw oc l1 q1 d1 c2 led_out(+) led_out( ? ) q2 c13 c12 d3 c10 c11 vcc_in er_out on/off pwm_in s_gnd q3 c3 c4 r1 r13 q4 c1 c9 p_in p_gnd c5 c8 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11 r12 r14 r15 r16 r17 r18 r19 r21 d2 c6 r20 r22 r23 14 3 2 drv gnd fset (n.c.) pwm u1 BL0100A 7 6 5 12 13 14 ovp reg vref ifb comp 98 10 11 er c7 tc_BL0100A_2_r1 figure 5-1 typical application circuit downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 7 apr. 04 , 2 01 4 6. package diagram ? soic14 notes: 1) dimension is in millimeters 2) pb -free. device composition compliant with the rohs directive 7. marking diagram 1 14 part number b l 0 1 0 0 a s k y m d lot number y is the last digit of the year (0 to 9) m is the month (1 to 9, o, n or d) d is a period of days (1 to 3) : 1 : 1 st to 10 th 2 : 11 th to 20 th 3 : 21 st to 31 st sanken control number 1.27 0.43 0.15 1.45 3.9 6.0 0.6 0.25 8.65 downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 8 apr. 04 , 2 01 4 8. functional description ? all of the parameter values used in these descriptions are typical values, unless they are specified as minimum or maximum. ? with regard to current direction, "+" indicates sink current (toward the ic) and " C " indicates source current (from the ic). 8.1 startup operation figure 8-1 shows the vcc pin peripheral circuit. the vcc pin is the power supply input for control circuit from the external power supply. when the vcc pin voltage increases to the operation start volta ge , v cc(on) = 9.6 v, the control circuit starts operation. after that, when the pwm pin voltage exceeds the pwm pin on threshold voltage, v pwm(on) of 1.5 v (less than absolute maximum voltage of 5 v), the comp pin charge current at startup, i comp(s) = ? 11 a, flows from the comp pin. this charge current flows to capacitors at the comp pin. when the comp pin voltage increases to the comp pin voltage at oscillation start, v comp(on) = 0.50 v or more, the control circuit starts switching operation. as shown in figure 8-2, when the vcc pin voltage decreases to the operation stop voltage , v cc(off) = 9.1 v, the control circuit stops operation, by the uvlo (undervoltage lockout) circuit, and reverts to the state before startup. external power supply u1 c3 comp gnd pwm 8 13 7 4 c9 c11 c10 r23 vcc figure 8-1 vcc pin peripheral circuit i cc i cc on v cc off v cc on v cc start stop figure 8-2 v cc versus i cc when the on-duty of the pwm dimming signal is small, the charge current at the comp pin is controlled as follows in order to raise the output current quickly at startup. figure 8-3 shows the operation waveform with the pwm dimming signal at startup. pwm pin dimming signal comp pin voltage ifb pin voltage constant current control comp pin charge current ic switching status off on v comp(on) vref pin voltage v ifb(comp.vr) i comp(s) i comp(src) 0 0 0 0 vcc pin voltage v cc(on) 0 figure 8-3 startup operation during pwm dimmi ng while the ifb pin voltage increases to the ifb pin voltage at comp charge switching, v ifb(comp.vr) , a capacitors at the comp pin are charged by i comp(s) = C 11 a. during this period, they are charged by the comp pin source current, i comp(src) = C 57 a, when the pwm pin voltage is 1.5 v or more. thus, the comp pin voltage increases immediately. when the ifb pin voltage increases to v ifb(cmp1.vr) or more, the comp pin source current is controlled according to the feedback amount, and the output current is controlled to be constant. the on-duty gradually becomes wide according to the increase of the comp pin voltage, and the output power increases (soft start operation). thus, power stresses on components are reduced. when the vcc pin voltage decreases to the operation stop voltage or less, or the auto restart operation (see the section 8.5 protection function) after protection is achieved, then the control circuit stops switching operation, and capacitors at the comp pin are discharged by the comp pin reset current, i comp(r) = 360 a, simultaneously. the soft start operation is achieved at restart. the ic is operated by auto restart 1 at startup downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 9 apr. 04 , 2 01 4 operation. see the section 8.5 protection function about the caution of startup operation. v ifb(comp.vr) is determined by the vref pin voltage, as shown i n figure 8-4. when vref pin voltage is 1v, the value of v ifb(comp.vr) becomes 0.60 v. v ifb(comp.vr) vref pin voltage 0.15v 1.2v 0.25v 2v 1v 0.6v figure 8-4 vref pin voltage versus ifb pin voltage at comp charge switching 8.2 constant current control operation figure 8-5 shows the ifb pin peripheral circuit. when q2 turns on, the led output current, i out(cc) , is detected by the current detection resistor, r11. the ic compares the ifb pin voltage with the vref pin voltage by the internal error amplifier, and controls the ifb pin voltage so that it gets close to the vref pin voltage. the reference voltage at the vref pin is the divided voltage of the reg pin voltage, v reg = 5 v, by r20 and r21, and thus this voltage can be externally adjusted. the setting current, i out(cc) , of the led_out can be calculated as follows. sen ref ) cc ( out r v i ? (8 - 1) where: v ref is the vref pin voltage. the value is recommended to be 0.5 v to 2.0 v. r esn is the value of r11 u1 output current detection resistor abnormal detector vref error amp. q2 r11 1 12 ifb i out(cc) led_out(+) led_out( - ) reg vcc 8 2 r20 r21 5v figure 8-5 ifb pin peripheral circuit 8.3 pwm dimming function figure 8-6 shows the peripheral circuit of pwm pin and sw pin. the pwm pin is used for the pwm dimming signal input. the sw pin drives the gate of external mosfet, q2. the sw pin voltage is turned on / off by pwm signal, and thus the dimming of led is controlled by pwm signal input. as shown in figure 8-7, when the pwm pin voltage becomes the pwm pin on threshold voltage, v pwm(on) = 1.5 v or more, the sw pin voltage becomes v cc . when the pwm pin voltage becomes the pwm pin off threshold voltage, v pwm(off) = 1.0 v or less, the sw pin voltage becomes 0.1 v or less. the pwm pin has the absolute maximum voltage of ? 0.3 v to 5.0 v, and the input impedance, r pwm , of 200 k . the pwm dimming signal should meet these specifications and threshold voltages of v pwm(on) and v pwm(off) . u1 sw q2 r11 9 drive pwm osc main logic 4 pwm pwm_in pwm pulse detector vcc led led_out (+) led_out ( ? ) figure 8-6 the peripheral circuit of pwm pin and sw pin. pwm pin voltage sw pin voltage v pwm(on) v pwm(off) vcc time time 0.1v figure 8-7 the waveform of pwm pin and sw pin 8.4 gate drive figure 8-8 shows the peripheral circuit of drv pin and sw pin and fset pin. the drv pin is for boost mosfet, q1 . the sw pin is for dimming mosfet, q2 . table 8-1 shows drive voltages and currents of drv pin and sw pin. q1 and q2 should be selected so that these v gs(th) threshold voltages are less than v cc enough over entire operating temperature range. downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 10 apr. 04 , 2 01 4 peripheral components of q1 (r1, r2, and d2) and q2 (r8, r9, and d3) affect losses of power mosfet, gate waveform (ringing caused by the printed circuit board trace layout), emi noise, and so forth, these va lues should be adjusted based on actual operation in the application. r3 for q1 and r10 for q2 are used to prevent malfunctions due to steep dv/dt at turn-off of the power mosfet, and these resistors are connected near each the gate of the power mosfets and the ground line side of the current detection resistance. the reference value of them is from 10 k to 100 k. l1 c2 q2 r11 d1 q1 c1 led_out(+) r1 r2 r3 r4 r8 r9 r10 d2 d3 drv sw 10 9 u1 pwm osc main logoc drive drive vcc vcc gnd fset c8 r22 6 7 figure 8-8 the peripheral circuit of drv pin, sw pin and fset pin table 8-1 drive voltage and current pins drive voltage, v drv drive current, i drv high low source sink drv v cc 0.1v or less C 0.36 a 0.85 a sw v cc 0.1v or less C 85 ma 220 ma as shown in figure 8-9, the pwm oscillation frequency of drv pin can be set between 100 khz and 500 khz, depending on the value of r22 connected to fset pin, r fset . figure 8-9 relation between pwm oscillation frequency and r fset 8.5 protection function as shown in table 8-2, the ic performs protection operations according to kind of abnormal state. in all protection functions, when the fault condition is removed, the ic returns to normal operation automatically. the intermitted oscillation operation reduces stress on the power mosfet, the secondary rectifier diode, and so forth. table 8-2 relationship between a kind of abnormal state and protection operations abnormal states protection operations 1 overcurrent of boost circuit (ocp) auto restart 1 2 overcurrent of led output (led_ocp) 3 overvoltage of led_out(+) (ovp) 4 short mode between led_out( ? ) and gnd 5 short mode of led current detection resistor (r sen _short) 6 short mode of both ends of led output auto restart 2 7 open mode of led current detection resistor (r sen _open) 8 overtemperature of junction of ic (tsd) auto restart 3 auto restart 1: as shown in figure 8- 10 , the ic repeats an intermitted oscillation operation, after the detection of any one of abnormal states 1 to 5 in table 8-2. this intermitted oscillation is determined by t ars1 or t ars2 , and t aroff1 . the t ars1 is an oscillation time in the first intermitted oscillation cycle, t ar1 . the t ars2 is an oscillation time in the second and subsequent intermitted oscillation cycle, t ar2 . the t aroff1 is a non-oscillation time in all intermitted oscillation cycle. in case pwm dimming frequency is low and the on -duty is small, the startup operation, the restart operation from on-duty = 0 % and the restart operation from intermitted oscillation operation need a long time. thus the value of t ars1 and t ars2 depend on frequency and on-duty of the pwm dimming signal, as shown in figure 8- 12 and figure 8- 13 . in case the on-duty is 100 %, the value of t ars1 is 61.4 ms, and t ar s2 is 41.0 ms . the value of t aroff1 is about 1.3 s. auto restart 2: as shown in figure 8- 11 , the ic stops the switching operation immediately after the detection of abnormal states 6 or 7 in table 8-2, and repeats an intermitted oscillation operation. in the intermitted oscillation cycle, the t arsw is an oscillation time, the t aroff1 is a non-oscillation time. the value of t arsw is a few microseconds . the value of t ars2 is derived from figure 8- 11 , and t aroff2 is calculated as follows: 1 aroff arsw 2ars 2 aroff t t t t ? ? ? (8 -2) 0 100 200 300 400 500 600 1 10 100 1000 pwm oscillation frequency of drv pin (khz) r fset (k ) downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 11 apr. 04 , 2 01 4 in case the on-duty is 100%, the value of t aroff2 becomes about 1.341 ms. auto restart 3: the ic stops the switching operation immediately after the detection of abnormal states 8 in table 8-2, and keeps a non-oscillation. t ars1 t ars2 t ars2 t aroff1 t aroff1 t aroff1 t ar2 t ar2 t ar1 abnormal state sw pin voltage time release return to normal operation figure 8- 10 auto restart 1 t arsw t ars2 t ars2 t aroff2 t arsw t aroff2 t aroff2 sw pin voltage time release return to normal operation abnormal state t aroff1 t aroff1 t aroff1 figure 8- 11 auto restart 2 figure 8- 12 pwm dimming on -duty versus t ars1 figure 8- 13 pwm dimming on -duty versus t ars2 the operating condition of auto restart 1 and 2 is as follows: < the operating condition of auto restart 1 > the auto restart 1 is operated by the detection signals of the oc pin or ifb pin. operation by the detection signal of oc pin: when the oc pin voltage increase to the oc pin overcurrent protection threshold voltage , v ocp = 0.60 v, or more, the operation of the ic switches to auto restart 1. when the fault condition is removed and the oc pin voltage decreases to under v ocp , the ic returns to normal operation automatically. operation by the detection signal of ifb pin: as shown in figure 8- 14 , ifb pin has two types of threshold voltage. these threshold voltages depend on the vref pin voltage, as shown in figure 8- 15 . ifb pin voltage sw pin voltage time v ifb(ocl.vr) v ifb(ocl-off.vr) auto restart 1 v ifb(ar.vr) time return to normal operation v ifb(comp) figure 8- 14 ifb pin threshold voltage and auto restart 1 operation figure 8- 15 vref pin voltage versus ifb pin threshold voltages 0 500 1000 1500 2000 2500 0.01 0.1 1 10 100 t ars1 (ms) duty (%) 0 200 400 600 800 1000 1200 1400 0.01 0.1 1 10 100 t ars2 (ms) duty (%) 0.1 1.0 10.0 0.1 1.0 ifb pin threshold voltages (v) vref pin voltage (v) v ifb(ocl.vr) v ifb(ocl.vr) 0.25v 0.125v 0.4v 0.5v 1.0v 3.2v 4.0v v ifb(ar.vr) v ifb(ocl.vr) : ifb pin overcurrent protection low threshold voltage v ifb(ocl-off.vr) :ifb pin overcurrent protection release threshold vol tage v ifb(ar.vr) :ifb pin auto restart operation threshold voltage f dm = 100 hz f dm = 300 hz f dm : pwm dimming frequency f dm = 100 hz f dm = 300 hz f dm : pwm dimming frequency downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 12 apr. 04 , 2 01 4 1) in case ifb pin voltage increased when the fb pin voltage increase to v ifb(ocl.vr) in figure 8- 15 , or more, the operation of the ic switches to auto restart 1. when the fault condition is removed and the ifb pin voltage decreases to v ifb(ocl-off.vr) in figure 8- 15 , or less, the ic returns to normal operation automatically. 2) in case ifb pin voltage decreased when the fb pin voltage decrease to v ifb(ar.vr) in figure 8- 15 , or more, the operation of the ic switches to auto restart 1. when the fault condition is removed and the ifb pin voltage increases to above v ifb(comp) , the ic returns to normal operation automatically. < the operating condition of auto restart 2 > the auto restart 2 is operated by the detection signal of the ifb pin. as shown in figure 8- 16 , when the fb pin voltage increase to the ifb pin overcurrent protection high threshold voltage, v ifb(och) = 4.0 v, or more, the operation of the ic switches to auto restart 2, and the ic stops switching operation immediately. when the fault condition is removed and the ifb pin voltage decreases to under v ifb(och) , the operation of the ic switches to auto restart 1. ifb pin voltage sw pin voltage time return to normal operation v ifb(ocl-off.vr) auto restart 2 auto restart 1 v ifb(och) figure 8- 16 ifb pin threshold voltage and auto restart 2 operation < caution of startup operation > when the led current is low and the ifb pin voltage is less than v ifb(ar.br) , during startup for example, the ic is operated by auto restart 1. if the startup time is too long, the ic operation becomes the intermitted oscillation by the auto restart 1. it becomes cause of the fault startup operation, thus the startup time should be set less than t ars1 in figure 8- 10 . the protection operation according to the abnormal states in table 8-2 is described in detail as follows: 8.5.1 overcurrent of boost converter part (ocp) when the oc pin detects the overcurrent of boost circuit, the ic switches to auto restart 1. figure 8- 17 shows the peripheral circuit of oc pin. when q1 turns on, the current flowing to l1 is detected by r4 , and the voltage on r4 is input to the oc pin. when the oc pin voltage increases to the oc pin overcurrent protection threshold voltage, v ocp = 0.60 v or more, the on-duty becomes narrow by pulse- by -pulse basis, and the output power is limited. l1 c2 q2 d1 q1 c12 r4 led_out(+) led_out(-) u1 oc 11 gnd 7 r11 r5 i l(on) figure 8- 17 oc pin peripheral circuit 8.5.2 overcurrent of led output (led_ocp) figure 8- 18 shows the peripheral circuit of ifb pin and comp pin. when q2 turns on, the output current is detected by r11. when the boost operation cannot be done by failure such as short circuits in led string, the ifb pin voltage is increased by the increase of led current. there are three types of operation modes in led_ocp state. (1) when the ifb pin voltage is increased by the increas e of led current, comp pin voltage is decreases. in addition, when the comp pin voltage decreases to the comp pin voltage at oscillation stop, v comp(off) = 0.25 v or less, the ic stops switching operation, and limits the increase of the output current. when ifb pin voltage is decreased by the decrease of led current, comp pin voltage increases. when comp pin voltage becomes v comp(on) = 0.50 v or more, the ic restarts switching operation. (2) when ifb pin voltage becomes v ifb(ocl.vr) or more (see figure 8- 15 ), the ic switches to auto restart 1. (3) the led current increases further and when the ifb pin voltage increases to the ifb pin overcurrent protection high threshold voltage, v ifb(och) = 4.0 v or more, the ic switches to auto restart 2. downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 13 apr. 04 , 2 01 4 u1 output current detection resistor q2 r11 12 ifb led_out(+) led_out( - ) 13 comp r23c10 c11 feedback control oc control figure 8- 18 the peripheral circuit of ifb pin and comp pin 8.5.3 overvoltage of led_out (+) (ovp) figure 8- 19 shows ovp pin peripheral circuit. the ovp pin detects the divided led output voltage by r6 and r7. when the led_out (+) or the ifb pin is open and the ovp pin voltage increases to the ovp pin overvoltage protection threshold voltage, v ovp = 3.00 v, the ic immediately stops switching operation. when the ovp pin voltage decreases to the ovp pin overvoltage protection release threshold voltage, v ovp(off) = 2.75 v or the ifb pin voltage decreases to v ifb(ar.vr) in figure 8- 15 , then the ic switches to auto restart 1. l1 c2 q2 d1 q1 c7 r6r7 r4 led_out(+) led_out(-) u1 ovp 3 gnd 7 r11 figure 8- 19 ovp pin peripheral circuit 8.5.4 short mode between led_out( ? ) and gnd when the led_out ( C ) and the gnd are shorted, and the ifb pin voltage decreases to v ifb(ar.vr) in figure 8- 15 , then the ic switches to auto restart 1. 8.5.5 short mode of led current detection resistor (r sen _short) when the output current detection resistor, r11, is shorted, the ifb pin voltage decreases. when the ifb pin voltage decreases to v ifb(ar.vr) in figure 8- 15 , then the ic switches to auto restart 1. 8.5.6 short mode of led output both ends when the led_out (+) and led_out ( C ) are shorted, the short current flows through the detection resistor (r11) while q2 turns on. the ifb pin detects the voltage rise of the detection resistor. when the ifb pin voltage increases to the ifb pin overcurrent protection high threshold voltage, v ifb(och) = 4.0 v or more, the ic switches to auto restart 2. 8.5.7 open mode of led current detection resistor (r sen _open) when the output current detection resistor, r11, is open, the ifb pin voltage increases. when the ifb pin voltage increases to the ifb pin overcurrent protection high threshold voltage, v ifb(och) = 4.0 v or more, the ic switches to auto restart 2. 8.5.8 overtemperature of junction of ic (tsd) when the temperature of the ic increases to t j( tsd) = 125 c (min) or more , the tsd is activated , and the ic stops switching operation. when the junction temperature decreases by t j(tsd) ? t j(tsd)hys after the fault condition is removed, the ic returns to normal operation automatically. 8.6 error signal output function when an external circuit such as microcomputer uses the error signal output, configure the peripheral circuit of er pin using the pull-up resistor, r8, and the protection resistor of er pin, r er , as shown in figure 8- 20 . the er pin is connected to internal switch. when the protection function is active, the internal switch becomes off and er_out becomes reg pin voltage from 0 v. the resistances of r17 and r er are about 10 k . r17 reg er 2 14 gnd 7 c6 r er er_out auto restart protection figure 8- 20 er pin peripheral circuit downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 14 apr. 04 , 2 01 4 9. design notes 9.1 peripheral components take care to use the proper rating and proper type of components. ? input and output electrolytic capacitors, c1 and c2 ? apply proper design margin to accommodate ripple current, voltage, and temperature rise. ? use of high ripple current and low impedance types, designed for switch-mode power supplies, is recommended, depending on their purposes. ? inductor,l1 ? apply proper design margin to temperature rise by core loss and copper loss. ? apply proper design margin to core saturation ? current detection resistors , r4 and r11 choose a type of low internal inductance because a high frequency switching current flows to the current detection resistor, and of properly allowable dissipation. 9.2 inductor design parameters the crm * or dcm* mode of boost converter with pwm dimming can improve the output current rise during pwm dimming. * crm is the critical conduction mode, dcm is the discontinuous conduction mode. the crm or dcm inductor design procedure is described as follow: (1) on -duty setting the output voltage of boost converter is more than the input voltage. the on-duty, d on can be calculated using following equation. the equality of the equation means the condition of crm mode operation and the inequality means that of dcm mode operation. out in out on v v v d ? ? (9 - 1) where: v in is the minimum input voltage, v out is the maximum forward voltage drop of led string. d on is selected by the above equation applied to crm or dcm mode. in case f pwm = 100 khz, the range of d on should be 1.4 % to 90 %. in case f pwm = 500 khz, the range of d on should be 7 % to 90 %. (the minimum value results from the condition of t min = 140 ns, and f pwm . the maximum value is d max ). (2) pwm oscillation frequency selection the pwm oscillation frequency of drv pin, f pwm , depends on the value of r22 connected to f set pin. the value of f pwm is set by figure 8-9. (3) inductance value, l the inductance value, l, for dcm or crm mode can be calculated as follow: ? ? ? ? in ut o pwm out 2 on in v v f i 2 d v l ? ? ? ? ? ? (9 - 2) where: i out is the maximum output current, f pwm is the maximum operation frequency of pwm (4) peak inductor current, i lp pwm on in lp f l d v i ? ? ? (9 - 3) (5) inductor selection the inductor should be applied the value of inductance, l, from equation (9-2) and the dc superimposition characteristics being higher than the peak inductor current, i lp , from equation (9-3). 9.3 pc d trace layout and component placement since the pcb circuit trace design and the component layout significantly affects operation, emi noise, and power dissipation, the high frequency pcb trace as shown in figure 9-1 should be low impedance with small loop and wide trace. l1 c1 q1 c2 d1 figure 9-1 high-frequency current l oops (hatched areas) in addition, the ground traces affect radiated emi noise, and wide, short traces should be taken into account. figure 9-2 shows the circuit design example. (1) main circuit trace layout this is the main trace containing switching currents, and thus it should be as wide trace and small loop as possible. c1 should be connected near the inductors, l1, in order to reduce impedance of the high frequency current loop. (2) control ground trace layout since the operation of ic may be affected from the large current of the main trace that flows in control ground trace, the control ground trace should be downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 15 apr. 04 , 2 01 4 connected at a single point grounding of point a with a dedicated trace. (3) current detection resistor trace layout r4 and r11 are current detection resistors. the trace from the base of current detection resistor should be connected to the pin of ic with a dedicated trace. (4) comp pin trace layout for compensation component r23, c10 and c1 1 are compensation components. the trace of the compensation component should be connected as close as possible to the pin of ic, to reduce the influence of noise. (5) bypass capacitor trace layout on vcc , reg, and vref pins c9 , c6 and c5 of bypass capacitors, connected to vcc, reg, and vref pins respectively, should be connected as close as possible to the pin of ic (6) power mosfet gate trace layout r3 for q1 and r10 for q2 should be connected near each the gate of the power mosfets and the ground line side of the current detection resistance. peripheral components of q1 (r1, r2, and d2) and q2 (r8, r9, and d3) should be connected as close as possible between each the gate of the power mosfets and the pin of ic. vcc sw oc c13 c12 c10 c11 vcc_in er_out on/off pwm_in s_gnd q3 c3 c4 r13 q4 c9 c5 c8 r5 r12 r14 r15 r16 r17 r18 r19 r21 c6 r20 r22 r23 14 3 2 drv gnd fset (n.c.) pwm u1 BL0100A 7 6 5 12 13 14 ovp reg vref ifb comp 98 10 11 er c7 f1 l1 q1 d1 c2 led_out(+) led_out( ? ) q2 d3 r1 c1 p_in p_gnd r2 r3 r4 r6 r7 r8 r9 r10 r11 d2 (1) main circuit trace should be as wide trace and small loop. (6) power mosfet gate trace layout r3(r10) should be connected near gate of q1(q2) and ground line side of r4(r11). r1,r2 and d2 (r8, r9 and d3) should be connected as close as possible between gate of q1(q2) and drv(sw) pin. a (4) comp pin peripheral components should be connected as close as possible to the pin of ic. (2) control ground trace layout should be connected at a single point grounding of point a with a dedicated trace (5)bypass capacitor c5,c6,c8 should be connected as close as possible to the pin of ic. (3) current detection trace should be connected to the pin of ic with a dedicated trace. figure 9-2 peripheral circuit example around the ic downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 16 apr. 04 , 2 01 4 10. reference design of power supply as an example, the following show a power supply specification, circuit sc hematic, bill of materials, and transformer specification. this reference design is the example of the value of parts, and shou ld be adjusted based on actual operation in the application. ? power supply specification ic BL0100A input voltage dc 24 v maximum output power 20 w (max.) drv pin oscillation frequency 100 khz output voltage 50 v output current 400 ma ? circuit schematic f1 vcc sw oc l1 q1 d1 c2 led_out(+) led_out( ? ) q2 c13 c12 d3 c10 c11 vcc_in er_out on/off pwm_in s_gnd q3 c3 c4 r1 r13 q4 c1 c9 p_in p_gnd c5 c8 r2 r3 r4 r5 r6 r7 r8 r9 r10 r11 r12 r14 r15 r16 r17 r18r20 r22 d2 c6 r21 r24 r25 14 3 2 drv gnd fset (n.c.) pwm u1 BL0100A 7 6 5 12 13 14 ovp reg vref ifb comp 98 10 11 er c7 tc_BL0100A_3_r1 r19 r23 downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 17 apr. 04 , 2 01 4 ? bill of materials symbol part type ratings (1) recommended sanken parts symbol part type ratings (1) recommended sanken parts f1 fuse 3 a r3 general, chip, 2012 10 k l1 inductor 50 h, 3 a r4 general 0.22 , 2 w d1 fast recovery 200 v, 1.5 a el 1z r5 general, chip, 2012 100 d2 schottky 30 v, 1 a sjpa- d3 r6 (3) general, chip, 2012 220 k d3 schottky 30 v, 1 a sjpa- d3 r7 (2) general, chip, 2012 11 k q1 power mosfet 200 v, 45 m (typ.) skp202 r8 general, chip, 2012 470 q2 power mosfet 100 v, 1 (typ.) r9 general, chip, 2012 1.5 k q3 pnp transistor ? 50 v, 0.1 a r10 general, chip, 2012 10 k q4 npn transistor 50 v, 0.1 a r 11 general 1.35 , 1 w c1 electrolytic 50 v, 22 f r12 general, chip, 2012 1.5 k c2 electrolytic 100 v, 100 f r13 general, chip, 2012 10 k c3 electrolytic 50 v, 47 f r14 general, chip, 2012 12 k c4 ceramic, chip, 2012 50 v, 0.1 f r15 general, chip, 2012 10 k c5 ceramic, chip, 2012 0.1 f r16 general, chip, 2012 15 k c6 ceramic, chip, 2012 10 nf r17 general, chip, 2012 10 k c7 ceramic, chip, 2012 0.1 f r18 general, chip, 2012 82 k c8 (2) ceramic, chip, 2012 0.1 f r19 (2) general, chip, 2012 560 c9 ceramic, chip, 2012 50 v, 0.1 f r20 general, chip, 2012 10 k c10 ceramic, chip, 2012 0.047 f r21 general, chip, 2012 10 k c 11 ceramic, chip, 2012 2200 pf r22 general, chip, 2012 33 k c 12 (2) ceramic, chip, 2012 100 pf r23 general, chip, 2012 1 k c 13 (2) ceramic, chip, 2012 100 pf r24 general, chip, 2012 open r1 general, chip, 2012 10 r25 general, chip, 2012 22 k r2 general, chip, 2012 100 u1 ic BL0100A (1) unless otherwise specified, the voltage rating of c apacitor is 50v or less, and the power rating of re sistor is 1/8w or less. (2) it is necessary to be adjusted based on actual operation in the application. (3) resistors applied high dc voltage and of high resistance are recommended to select resistors designed against electromigration or use combinations of resistors in series for that to redu ce each applied voltage, according to the requirement of the applicati on. downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 18 apr. 04 , 2 01 4 operating precautions in the case that you use sanken products or design your products by u sing sanken products, the reliability largely depends on the degree of derating to be made to the rated values. derating ma y be interpreted as a case that an operation range is set by derating the load from each rated value or surge voltage or noise is considered for derating in order to assure or improve the reliability. in general, derating factors include electric stress es such as electric voltage, electric current, electric power etc., environmental stresses such as ambient temperature, humidity etc. and thermal stress caused due to self-heating of semiconductor products. for these stresses, instantaneo us values, maximum values and minimum values must be taken into consideration. in addition, it should be noted that since power devices o r ics including power devices have large self-heating value, the degree of derating of junction tem perature affects the reliability significantly. because reliability can be affected adversely by improper storage environmen ts and handling methods, please observe the following cautions. cautions for storage ? ensure that storage conditions comply with the standard temperature (5 to 3 5c) and the standard relative humidity (around 40 to 75%) ; avoid storage locations that experience extreme changes in temperature or h umidity. ? avoid locations where dust or harmful gases are present and avoid direct sunligh t. ? reinspect for rust on leads and solderability of the products that have bee n stored for a long time. cautions for testing and handling when tests are carried out during inspection testing and other standard test periods, protect the products from power surges from the testing device, shorts between the product pins, and w rong connections. ensure all test parameters are within the ratings specified by sanken for the products. soldering ? when soldering the products, please be sure to minimize the working time, within the following limits: ? 260 5 c 10 1 s (flow, 2 times) ? 380 10 c 3.5 0.5 s (soldering iron, 1 time) electrostatic discharge ? when handling the products, the operator must be grounded. grounded wr ist straps worn should have at least 1m of resistance from the operator to ground to prevent shock hazard, and it should be placed near the operator. ? workbenches where the products are handled should be grounded and b e provided with conductive table and floor mats. ? when using measuring equipment such as a curve tracer, the equipment shou ld be grounded. ? when soldering the products, the head of soldering irons or the solder bath must be grounded in order to prevent leak voltages generated by them from being applied to the products. ? the products should always be stored and transported in sanken shipp ing containers or conductive containers, or be wrapped in aluminum foil. downloaded from: http:///
BL0100A BL0100A- ds rev. 1. 2 sanken electric co.,ltd. 19 apr. 04 , 2 01 4 important notes ? the contents in this document are subject to changes, for improv ement and other purposes, without notice. make sure that this is the latest revision of the document before use. ? application and operation examples described in this document are quoted for the s ole purpose of reference for the use of the products herein and sanken can assume no respons ibility for any infringement of industrial property rights, intellectual property rights or any other rights of sanken or any third party which may result from its use. ? unless otherwise agreed in writing by sanken, sanken makes no warrantie s of any kind, whether express or implied, as to the products, including product merchantability, and fitness for a particular purpose and special environment, and the information, including its accuracy, usef ulness, and reliability, included in this document. ? although sanken undertakes to enhance the quality and reliability of its pro ducts, the occurrence of failure and defect of semiconductor products at a certain rate is inevitable. users of sank en products are requested to take, at their own risk, preventative measures including safety design o f the equipment or systems against any possible injury, death, fires or damages to the society due to device failure or malfunction. ? sanken products listed in this document are designed and intended for the use as components in general purpose electronic equipment or apparatus (home appliances, office equipment, telecommunication equipment, measuring equipment, etc.). when considering the use of sanken products in the applications where higher reliability is required (transportation equipment and its control systems, traffic signal contr ol systems or equipment, fire/crime alarm systems, various safety devices, etc.), and whenever long life expectancy is required even in general purpose electronic equipment or apparatus, please contact your nearest sanken s ales representative to discuss, prior to the use of the products herein. the use of sanken products without the written consent of sanken in th e applications where extremely high reliability is required (aerospace equipment, nuclear power control systems , life support systems, etc.) is strictly prohibited. ? when using the products specified herein by either (i) combining other products or materials therewith or (ii) physically, chemically or otherwise processing or treating the pro ducts, please duly consider all possible risks that may result from all such uses in advance and proce ed therewith at your own responsibility. ? anti radioactive ray design is not considered for the products listed herein. ? sanken assumes no responsibility for any troubles, such as dropping products caused during transportation out of sankens distribution network. ? the contents in this document must not be transcribed or copied without sankens written consent. downloaded from: http:///

▲Up To Search▲

Price & Availability of BL0100A

	To Download BL0100A Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .