NJU7650 -1- ver.2006-07-11 step-down switching regulator ic with constant current control general description package outline features product variation pwm switching control constant current control operating voltage 2.2v to 8v wide oscillator range 300khz to 1mhz maximum duty cycle 100% quiescent current 800 a typ. soft-start function internal : 16ms typ. or adjustable dead time control c-mos technology package outline NJU7650rb1 : tvsp8 pin configuration NJU7650 is a high speed low voltage operation switching regulator control ic with constant current control. it features a totem pole driver that can directly drive an external mos-fet. internal error amplifier and current sense amplifier provid e constant voltage/constant current control. it is applicable for led driver, battery charger and other ccc v applications. pin function 1. out 2. v + 3. fb 4. in-1 5. in-2 6. dtc 7. rt 8. gnd NJU7650rb1 1 8 2 7 3 6 4 5 NJU7650rb1 over current protection nju7630 nju7640 pwm control constant current control NJU7650
NJU7650 - 2 - ver.2006-07-11 block diagram buffer 0.5v osc 0.5 r t a uvlo soft start 0.8v 0.2v out gnd rt dtc r t fb v + in-1 in-2 pw m 1v error amp 0.2v current sense amp ? 1 ? 1
NJU7650 - 3 - ver.2006-07-11 absolute maximum ratings (ta=25c) parameter symbol maximum ratings unit supply voltage v + +9 v output pin current i o 50 ma power dissipation p d tvsp8 :320 mw operating temperature range t opr -40 ~ +85 c storage temperature range t stg -40 ~ +125 c recommended operating conditions (ta=25c) parameter symbol min. typ. max. unit operating voltage v + 2.2 ? 8 v oscillator timing resistor r t 30 47 120 k ? oscillation frequency f osc 300 700 1,000 khz electrical characteristics (v + =3.3v, r t =47k ? , ta=25c) parameter symbol test condition 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% 8 16 24 ms oscillator block rt pin voltage v rt -5% 0.5 +5% v oscillation frequency f osc 630 700 770 khz oscillate supply voltage fluctuations f dv v + =2.2v ~ 8v ? 1 ? % oscillate temperature fluctuations f dt ta = - 4 0 c ~ +85 c ? 3 ? %
NJU7650 - 4 - ver.2006-07-11 electrical characteristics (v + =3.3v, r t =47k ? , ta=25c) parameter symbol test condition min. typ. max. unit error amplifier block reference voltage 1 v b1 -1.0% 1.00 +1.0% v input bias current 1 i b1 -0.1 ? 0.1 a open loop gain 1 a v1 ? 80 ? db gain bandwidth product 1 g b1 ? 1 ? mhz i om+_1 v fb =1v, v in-1 =0.9v, v in-2 =0.1v 25 55 95 ma output source current 1 i om+_2 v fb =1v, v in-1 =0.9v, v in-2 =0.1v, v + =2.2v 4 9 16 ma output sink current 1 i om1- v fb =1v, v in-1 =1.1v, v in-2 =0.1v 0.10 0.16 0.22 ma current sense amplifier block reference voltage 2 v b2 -10% 0.2 +10% v input bias current 2 i b2 -0.1 ? 0.1 a open loop gain 2 a v2 ? 70 ? db gain bandwidth product 2 g b2 ? 1 ? mhz output sink current 2 i om2- v fb =1v, v in-1 =0.9v, v in-2 =0.3v 0.10 0.16 0.22 ma 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 0.5 0.56 v m ax d uty_1 v fb =0.9v 100 ? ? % maximum duty cycle m ax d uty_2 v fb =0.9v, r dtc =47k ? 40 50 60 % output block output high level on resistance r oh i o =-20ma ? 10 20 ? output low level on resistance r ol i o =+20ma ? 5 10 ? general characteristics quiescent current i dd r l =non load ? 800 1200 a
NJU7650 - 5 - ver.2006-07-11 typical applications step-down converter in-2 v in 1 fet sbd 2 3 4 5 6 7 8 r dtc c s in-1 fb v + dtc rt gnd out r t c out c in r2 r1 c nf r nf c l NJU7650 r cin r cnf c cnf v out gnd out r sc
NJU7650 - 6 - ver.2006-07-11 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 0246810 oscillation frequency fosc (khz) operating voltage v + (v) oscillation frequency vs. operating voltage (r t =47k ? , ta=25 o c) 0 20 40 60 80 100 0 20406080100 duty cycle m ax d uty (%) dead time control resistance r dtc (k ? ) duty cycle vs. r dtc (v + =3.3v, r t =47k ? , ta=25 o c) 0 200 400 600 800 1000 1200 1400 0246810 quiescent current i dd ( a) operating voltage v + (v) quiescent current vs. operating voltage (r t =47k ? , r l =non load, ta=25 o c) 0.996 0.998 1 1.002 1.004 0246810 reference voltage1 v b1 (v) operating voltage v + (v) error amplifier block reference voltage1 vs. operating voltage (ta=25 o c) 0.196 0.198 0.2 0.202 0.204 0246810 reference voltage2 v b2 (v) operating voltage v + (v) current sense amplifier block reference voltage2 vs. operating voltage (ta=25 o c)
NJU7650 -7- ver.2006-07-11 typical characteristics (v + =3.3v, gain=40db, ta=25 o c) 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 phase (deg) frequency f (khz) voltage gain av (db) phase gain 0 2 4 6 8 10 12 14 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) output high level on resistance r oh ( ? ) output block output high level on resistance vs. temperature (io=-20ma) v + =3.3v v + =1.95v v + =8v 0 2 4 6 8 10 12 14 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) output low level on resistance r ol ( ? ) output block output low level on resistance vs. temperature (io=+20ma) v + =3.3v v + =1.95v v + =8v 1 10 100 1000 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) output source current i om+ (ma) error amplifier block output source current1 vs. temperature (v fb =1v, v in-1 =0.9v, v in-2 =0.1v) v + =3.3v v + =1.95v v + =8v 0 0.05 0.1 0.15 0.2 -50-250 255075100125 ambient temperature ta ( o c) output sink current i om- (ma) error amplifier, current sense amplifier block output sink current vs. temperature v + =1.95v, 3.3v, 8v
NJU7650 - 8 - ver.2006-07-11 typical characteristics 0.99 0.995 1 1.005 1.01 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) reference voltage1 v b1 (v) error amplifier block reference voltage1 vs. temperature (v + =3.3v) 0.19 0.195 0.2 0.205 0.21 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) reference voltage2 v b2 (v) current sense amplifier block reference voltage2 vs. temperature (v + =3.3v) 640 660 680 700 720 740 760 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) oscillator frequency f osc (khz) oscillator frequency vs. temperature (v + =3.3v, r t =47k ? ) 8 10 12 14 16 18 20 22 24 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) soft start time tss (ms) soft start time vs. temperature (v + =3.3v) 1.86 1.9 1.94 1.98 2.02 2.06 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) threshold voltage (v) under voltage lockout block vs. temperature v t_off v t_on 0 200 400 600 800 1000 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) quiescent current i dd ( a) quiescent current vs. temperature (v + =3.3v, r t =47k ? )
NJU7650 - 9 - ver.2006-07-11 memo [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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