NJU7691 - 1 - ver.2010-04-14 300ma synchronous step-dow n switching regulator ic general description package outline features 300ma synchronous step-down pwm switching control operating voltage 2.2v to 7v wide oscillator range 300khz to 1mhz maximum duty cycle 100% stand-by current 5 a max. soft-start function 4ms typ. over current protection c-mos technology package outline NJU7691rb1 : tvsp8 pin configuration the NJU7691 is a synchronous rectification type switching regulator ic with a power mosfet (300ma output). it has an over current detection and an overheat protection circuit. therefore, the circui t can be configured with fe w external parts. the output voltage can be set from 0.8v. it is suitable fo r supplying power to a digital chip and a logic ic with lo w voltage. pin function 1. sw 2. v + 3. fb 4. in- 5. on/off 6. rt 7. agnd 8. pgnd NJU7691rb1 1 8 2 7 3 6 4 5 NJU7691rb1
NJU7691 - 2 - ver.2010-04-14 block diagram buffer 0.5v osc uvlo soft start vref 0.8v 0.8v 0.2v sw pgnd rt r t in- fb v + pwm er ? amp a gnd ocp standby on/off on/off high: on low : off (standby) tsd 100k ?
NJU7691 - 3 - ver.2010-04-14 absolute maximum ratings (ta=25c) parameter symbol maximum ratings unit supply voltage v + +8 v on/off pin voltage v on/off +8 v power dissipation p d 580 (*1) mw operating temperature range t opr -40 ~ +85 c storage temperature range t stg -40 ~ +150 c (*1): mounted on glass epoxy board based on eia/jedec. (76.2 114.3 1.6mm: 2-layers) recommended operat ing conditions parameter symbol min. typ. max. unit operating voltage v + 2.2 ? 7 v output current (*2) i out ? ? 300 ma oscillator timing resistor r t 30 47 120 k ? oscillation frequency f osc 300 700 1,000 khz (*2): steady operating electrical characteristics (v + =v on/off =3.3v, r t =47k ? , ta=25c) parameter symbol test condi tion min. typ. max. unit under voltage lockout block on threshold voltage v t_on v + = l h 1.9 2.0 2.1 v off threshold voltage v t_off v + = h l 1.8 1.9 2.0 v hysteresis voltage v hys 60 100 ? mv soft start block soft start time t ss v t_on duty=80% 2 4 8 ms oscillator block oscillation frequency f osc 630 700 770 khz oscillate supply voltage fluctuations f dv v + =2.2v ~ 7v ? 1 ? % oscillate temperature fluctuations f dt ta = - 4 0 c ~ +85 c ? 3 ? % error amplifier block reference voltage v b -1.0% 0.8 +1.0% v input bias current i b -0.1 ? 0.1 a open loop gain a v ? 80 ? db gain bandwidth product g b ? 1 ? mhz output source current i om+ v fb =1v, v in- =0.7v 20 35 50 a output sink current i om- v fb =1v, v in- =0.9v 1 2.5 5 ma
NJU7691 - 4 - ver.2010-04-14 electrical characteristics (v + =v on/off =3.3v, r t =47k ? , ta=25c) parameter symbol test condi tion min. typ. max. unit pwm comparate block v t_0 duty=0% 0.16 0.22 0.28 v input threshold voltage v t_50 duty=50% 0.44 0.50 0.56 v maximum duty cycle m ax d uty v fb =0.9v 100 ? ? % output block output high level on resistance r oh i sw =-200ma ? 0.9 1.2 ? output low level on resistance r ol i sw =+200ma ? 0.8 1.1 ? switching current limit i lim 500 650 800 ma high side sw leak current i leakh v on/off =0v ? ? 1 a output pull-down resistance r pd-sw 60 100 140 k ? on/off block on control voltage v on v on/off = l h 1.6 ? v + v off control voltage v off v on/off = h l 0 ? 0.3 v general characteristics quiescent current i dd r l =non load ? 1.3 1.6 ma standby current i dd_stb v on/off =0v ? ? 5 a typical applications on/ off v in v out 1 2 3 4 5 6 7 8 in- fb v + rt a gnd pgnd sw r t c out c in r2 r1 c nf r nf l NJU7691 c fb r fb on/off high: on low: off (standby) sbd
NJU7691 - 5 - ver.2010-04-14 typical characteristics 100 1000 10 100 oscillation frequency f osc (khz) oscillation frequency vs. timing resistance (v + =3.3v, ta=25 o c) timing resistance r t (k ? ) 660 680 700 720 740 02468 oscillation frequency fosc (khz) operating voltage v + (v) oscillation frequency vs. operating voltage (r t =47k ? , ta=25 o c) 0.78 0.79 0.8 0.81 0.82 02468 reference voltage v b (v) operating voltage v + (v) reference voltage vs. operating voltage (r t =47k ? , ta=25 o c) 400 500 600 700 800 900 02468 switching current limit i lim (ma) operating voltage v + (v) switching current limit vs. operating voltage (r t =47k ? , ta=25 o c) 0 0.5 1 1.5 2 2.5 3 02468 quiescent current i dd (ma) operating voltage v + (v) quiescent current vs. operating voltage (r t =47k ? , r l =non load, ta=25 o c) 0.001 0.01 0.1 1 10 100 02468 standby current i dd_stb (na) operating voltage v + (v) standby current vs. operating voltage (v on/off =0v, ta=25 o c)
NJU7691 - 6 - ver.2010-04-14 typical characteristics 0 15 30 45 60 0 45 90 135 180 0.1 1 10 100 1000 10000 error amplifier block voltage gain, phase vs. frequency (v + =3.3v, gain=40db, ta=25 o c) phase (deg) frequency f (khz) voltage gain av (db) phase gain 0 0.4 0.8 1.2 1.6 2 1 10 100 1000 switching current i sw (ma) output high level on resistance r oh (w) output block output high level on resistance vs. switching current (ta=25 o c) v + =2.2v v + =3.3v v + =7v 0 0.4 0.8 1.2 1.6 2 1 10 100 1000 switching current i sw (ma) output low level on resistance r ol ( ? ) output block output low level on resistance vs. switching current (ta=25 o c) v + =2.2v v + =3.3v v + =7v 0 0.5 1 1.5 2 2.5 3 -50-250 255075100125150 ambient temperature ta ( o c) output high level on resistance r oh ( ? ) output block output high level on resistance vs. temperature (isw=-200ma) v + =2.2v v + =3.3v v + =7v 0 0.5 1 1.5 2 2.5 3 -50-250 255075100125150 ambient temperature ta ( o c) output low level on resistance r ol ( ? ) output block output low level on resistance vs. temperature (isw=+200ma) v + =2.2v v + =3.3v v + =7v
NJU7691 - 7 - ver.2010-04-14 typical characteristics 2 3 4 5 6 7 8 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) soft start time tss (ms) soft start time vs. temperature (v + =3.3v) 0.78 0.79 0.8 0.81 0.82 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) reference voltage v b (v) reference voltage vs. temperature (v + =3.3v, r t =47k ? ) 640 660 680 700 720 740 760 -50-250 255075100125150 ambient temperature ta ( o c) oscillator frequency f osc (khz) oscillator frequency vs. temperature (v + =3.3v, r t =47k ? ) 200 300 400 500 600 700 800 900 1000 -50-250 255075100125150 ambient temperature ta ( o c) switching current limit i lim (ma) switching current limit vs. temperature (r t =47k ? ) v + =2.2v v + =3.3v v + =7v 0 0.5 1 1.5 2 2.5 3 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) high side sw leak current i leakh ( a) high side sw leak current vs. temperature (v + =3.3v, v on/off =0v, r t =47k ? ) 1.8 1.85 1.9 1.95 2 2.05 2.1 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) threshold voltage (v) under voltage lockout block vs. temperature v t_off v t_on
NJU7691 - 8 - ver.2010-04-14 typical characteristics 0 0.5 1 1.5 2 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) quiescent current i dd (ma) quiescent current vs. temperature (v + =3.3v, r t =47k ? ) 0.0001 0.001 0.01 0.1 1 10 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) standby current i dd_stb ( a) standby current vs. temperature (v + =3.3v, v on/off =0v) [caution] the specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. the application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights.
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