NJM2399 -1- ver. 1 6.5a high power dc/dc converter controller ic general description package outline features adjustable output voltage more than 5v operating voltage 7.5v to 40v pwm form switching power supply control internal high power transistor 6.5a (min.) fixed frequency oscillator 72khz (typ.) current sense amplifier under voltage lockout thermal shutdown circuit bipolar technology package outline to-220(5pin) block diagram oscillator thermal under voltage standby circuit error amplifier pwm comparator 6.5a power transistor current sense latch circuit s q r 5 4 3 2 1 on/off reference vref vref current detection transistor shutdown lockout voltage amplifier the NJM2399 is a high power step down dc/dc converter ic. it incorporates 6.5a power transistor, 2% accuracy precision voltage reference, fixed frequency pwm controller with cycle-by-cycle current limit and low power consumption stand b y function. the NJM2399 realizes a high power step down application with minimal external components. NJM2399tla2050 pin function 1:v fb 2:sw out 3:gnd 4:v + 5:stby (v comp ) pin 1 locates on the left side of the package drawing (top front view).
NJM2399 - 2 - ver. 1 absolute maximum ratings (ta=25c) parameter symbol maximum ratings unit maximum supply voltage v + 40 v switch output voltage vo (switch) -0.5 +vin v voltage feedback and compensation input voltage range v fb ,v comp -0.3 +7.0 v power dissipation p d to-220 (5pin) 16(t c 46c) w operating junction temperature tj -40 +150 c operating temperature range topr -40 ~ +85 c storage temperature range tstg -50 ~ +150 c thermal characteristics junction-to-ambient temperature ja 70 thermal resistance junction-to-case jc 6.5 c/w power dissipation vs. ambient temperature (t opr =-40~+85c, tj= ~+150c, p d =16w(t c 46c)) 0 2 4 6 8 10 12 14 16 18 25 50 75 100 ambient temperature ta (c) power dissipation p d (w) heat sink hs =10c/w hs =5c/w hs =20c/w without heat sink
NJM2399 - 3 - ver. 1 electrical characteristics (v + =12v, ta=25c) oscillator block parameter symbol test condition min. typ. max. unit frequency fosc v + =7.5v 65 72 79 khz error amplifier block parameter symbol test condition min. typ. max. unit voltage feedback input threshold v fb (th) 4.9 5.0 5.1 v line regulation regline v + =7.5 40v ? 0.03 0.08 %/v input bias current i b v fb =v fb (th)+0.15v ? 0.15 1.0 a ripple rejection psrr v + =10 20v ? 80 ? db output voltage swing v oh v ol isource=75 a,v fb =4.7v isink=0.4ma,v fb =5.3v 4.2 ? 4.9 1.6 ? 1.9 v v pwm comparator block parameter symbol test condition min. typ. max. unit duty cycle maximum minimum dc (max) dc (min) v fb =0v v fb =5.3v ? 0 95 0 ? 0 % % switch output block parameter symbol test condition min. typ. max. unit output voltage saturation v sat v + =7.5v,isource=6.5a ? v + -1.8 v + -2.1 v off-state leakage isw (off) v + =40v,sw out =0v ? 0 100 a current limit threshold ipk (switch) v + =7.5v 6.5 7.5 9.0 a switching times output voltage rise time output voltage fall time tr tf v + =40v,r out =7.7 ? ,v fb =0v v + =40v,r out =7.7 ? ,v fb =0v ? ? 100 50 ? ? ns ns under voltage lockout block parameter symbol test condition min. typ. max. unit startup threshold v th(uvlo) v + increasing 5.9 6.3 6.7 v hysteresis v h(uvlo) v + decreasing 0.6 0.8 1.0 v to ta l d e vi c e parameter symbol test condition min. typ. max. unit standby-state power supply current icc (stby) stby 0.1v ? 36 100 a operating-state power supply current icc v + =40v,v fb =0v duty ? cycle=max ? 40 53 ma keep the limit of maximum power dissipation not to operate thermal shutdown. low duty cycle pulse test is used to close its junction temperature to ambient temperature.
NJM2399 - 4 - ver. 1 marking 1 2399-050 jrc lot number 2 3 4 5 product number (NJM2399tla2050) logo typical characteristics -3 -2.5 -2 -1.5 -1 -0.5 0 0246810 switch output saturation voltage v sat (v) output source current i source (a) switch output saturation voltage vs. output source current (v + =7.5v, ta=25 o c) 0 0.5 1 1.5 2 00.511.52 output saturation voltage v sat(error) (v) output sink current i sink (ma) error amp block output saturation voltage vs. output sink current (v + =12v, v fb =5.5v, ta=25 o c) 0 30 60 90 120 150 180 0 5 10 15 20 25 30 35 40 standby-state power supply current i cc(stby) ( a) supply voltage v + (v) standby-state power supply current vs. supply voltage (ta=25 o c) 0 20 40 60 80 100 012345 duty cycle dc (%) compensation voltage v comp (v) duty cycle vs. compensation voltage (v + =12v, ta=25 o c)
NJM2399 - 5 - ver. 1 typical characteristics 4.9 4.95 5 5.05 5.1 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) voltage feedback input threshold v fb (v) voltage feedback input threshold vs. temperature (v + =12v) 0 0.1 0.2 0.3 0.4 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) input bias current i b ( a) error amp block input bias current vs. temperature (v + =12v, v fb =v fb (th)+0.15v) 60 65 70 75 80 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) oscillator frequency f osc (khz) oscillator frequency vs. temperature (v + =12v) 5 6 7 8 9 10 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) current limit threshold ipk (switch) (a) current limit threshold vs. temperature (v + =7.5v) 4 5 6 7 8 -50 -25 0 25 50 75 100 125 150 ambient temperature ta ( o c) under voltage lockout threshold v th(uvlo) (v) under voltage lockout threshold vs. temperature startup threshold v + decreasing startup threshold v + increasing 0 10 20 30 40 50 60 -50 -25 0 25 50 75 100 125 150 ambient tmperature ta ( o c) power supply current i cc (ma) operating-state power supply current vs. tmperature (v + =40v, v fb =0v, duty cycle=max)
NJM2399 - 6 - ver. 1 typical applications step-down converter vout cf NJM2399 4 2 1 3 5 vin r2 r1 cout l sbd *sbd rf cin vout = +1 v fb (th) [v] r2 r1 1) 5v and higher converter, the application must be connected r1 resistor according to above figure. 2) high current converter, the application must be placed cin capacitor next to NJM2399, which avoid the power-line fluctuation. 3) the sharp fluctuation of output load cause reverse voltage for inductance and over the supply-voltage for sw out terminal. to avoid this problem, the application must be placed sbd between terminal 2 and 4. timing chart oscillator 1) on 3) 2) 4) compensation switch output current sense thermal shutdown on on off off off 1) the NJM2399 generate square waves. the pwm comparator generate pwm signals to compare square waves and compensation voltage. 2) the switching duty is maximum 95%(typ.). 3) over the 7.5a(typ.) current, the output switch will be off to operate current limit protection. the NJM2399 sense the switching current of power transistor. 4) over the tj=180c(typ.), the switching will be off to operate thermal shutdown circuit.
NJM2399 -7- ver. 1 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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