NJU7677 - 1 - ver.2009-09-08 1.8v operate pwm contro l step-up / flyback sw itching regulator ic general description package outline features pwm switching control operating voltage 1.8v to 7v wide oscillator range 300khz to 1mhz maximum duty cycle 90% typ. quiescent current 600 a typ. soft-start function internal : 4ms typ. or adjustable dead time control timer latch for short circuit protection c-mos technology package outline NJU7677rb1 : tvsp8 pin configuration NJU7677 is a high speed low voltage operation switching regulator control ic. it features a to tem pole driver that can directl y drive an external mos-fet. internal soft-start function, dead time control and timer latch function are included, requiring no external components. all parameters can be optimized by additional external components fo r design flexibility. pin function 1. v + 2. fb 3. in- 4. scp 5. dtc 6. rt 7. gnd 8. out NJU7677rb1 1 8 2 7 3 6 4 5 NJU7677rb1
NJU7677 - 2 - ver.2009-09-08 block diagram buffer 0.6v 0.5v osc 1v 0.5 r t a 2k ? 2 a uvlo soft start vre f 1v 1v 0.65v 0.15v out gnd rt dtc r t scp in- fb v + pw m scp er ? amp latch
NJU7677 - 3 - ver.2009-09-08 absolute maximum ratings (ta=25c) parameter symbol maximum ratings unit supply voltage v + +8 v output pin current i o 50 ma power dissipation p d 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 + 1.8 ? 7 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 condi tion min. typ. max. unit under voltage lockout block on threshold voltage v t_on v + = l h 1.6 1.7 1.8 v off threshold voltage v t_off v + = h l 1.5 1.6 1.7 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 short circuit protection block input threshold voltage v t_pc fb pin 0.95 1.00 1.05 v charge current i chg v scp =0v 1.5 2 2.5 a latch mode on threshold voltage v t_la scp pin 0.90 1.00 1.10 v latch mode off threshold voltage v t_laoff scp pin 0.35 0.6 0.85 v oscillator block rt pin voltage v rt -8% 0.5 +8% v oscillation frequency f osc 630 700 770 khz oscillate supply voltage fluctuations f dv v + =1.8v ~ 7v ? 1 ? % oscillate temperature fluctuations f dt ta = - 4 0 c ~ +85 c ? 3 ? %
NJU7677 - 4 - ver.2009-09-08 electrical characteristics (v + =3.3v, r t =47k ? , ta=25c) parameter symbol test condi tion min. typ. max. unit error amplifier block reference voltage v b -1.0% 1.00 +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- =0.9v 20 35 50 a output sink current i om- v fb =1v, v in- =1.1v 1.0 4.0 12 ma pwm comparate block v t_0 duty=0% 0.10 0.16 0.22 v input threshold voltage v t_50 duty=50% 0.36 0.42 0.48 v m ax d uty_1 v fb =0.9v 85 90 95 % maximum duty cycle m ax d uty_2 v fb =0.9v, r dtc =43k ? 45 55 65 % output block r oh i o =-20ma ? 6 12 ? output high level on resistance r oh_1.8 i o =-20ma, v + =1.8v ? 10 20 ? r ol i o =+20ma ? 4.5 9 ? output low level on resistance r ol_1.8 i o =+20ma, v + =1.8v ? 8 16 ? general characteristics quiescent current i dd r l =non load ? 600 900 a
NJU7677 - 5 - ver.2009-09-08 typical applications step-up converter scp v + v out c scp 1 c in fet r2 sbd r1 c out l c nf r nf 2 3 45 6 7 8 r dtc c s in- fb v + dtc rt gnd out r t c NJU7677 flyback converter scp v + v out c scp 1 c in fet r2 sbd r1 c out t c nf r nf 2 3 4 5 6 7 8 r dtc c s in- fb v + dtc rt gnd out r t c NJU7677
NJU7677 - 6 - ver.2009-09-08 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 ? ) 80 85 90 95 100 100 1000 maximum duty cycle m ax d uty_1 (%) maximum duty cycle vs. oscillator frequency (v + =3.3v, ta=25 o c) oscillator frequency f osc (khz) 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 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) 0.99 0.995 1 1.005 1.01 02468 reference voltage v b (v) operating voltage v + (v) reference voltage vs. operating voltage (ta=25 o c) 0 200 400 600 800 1000 1200 02468 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)
NJU7677 - 7 - ver.2009-09-08 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 5 10 15 20 -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 + =1.8v v + =7v 0 2 4 6 8 10 12 14 16 -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 + =1.8v v + =7v
NJU7677 - 8 - ver.2009-09-08 typical characteristics 2 3 4 5 6 7 8 -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) 0.99 0.995 1 1.005 1.01 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) reference voltage v b (v) reference voltage 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 ? ) 40 50 60 70 80 90 100 -50 -25 0 25 50 75 100 125 ambient temperature ta ( o c) muximum duty cycle m ax d uty (%) muximum duty cycle vs. temperature (v + =3.3v) m ax d uty_1 m ax d uty_2 1.5 1.55 1.6 1.65 1.7 1.75 1.8 -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 ? )
NJU7677 - 9 - ver.2009-09-08 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.
|
