unisonic technologies co., ltd 3520 preliminary cmos ic www.unisonic.com.tw 1 of 7 copyright ? 2013 unisonic technologies co., ltd qw-r502-923.a pc power supply pwm supervisor ? description the utc 3520 pwm controller is designed for switching mode power supply for pcs. it provides all the functions necessary to monitor and control the output of the power supply. remote on/off control, power good circuitr y, some protection features against over-voltage and over-power are implements. it contains various functions, wh ich are over voltage protection (monitors 3.3v, 5v, 12v and pt input voltage level), under voltage protection (monitors 3.3v, 5v and 12v input voltage level), power good output (monitors the voltage level of power supply), remote on/off control and etc. it can mini mize external components of switching power supply systems in personal computer. ? features * complete pwm control and protection circuitry * over voltage protection for 3.3v / 5v / 12v / pt * under voltage protection for 3.3v / 5v / 12v * power good output is open drain output * pwm control output is open drain output * remote on/off function de?bounce time * 280ms uvp time delay * 280ms pg time delay * soft-start function built-in ? ordering information ordering number package packing lead free halogen free 3520L-D16-T 3520g-d16-t dip-16 tube note: xx: output voltage, refer to marki ng information.
3520 preliminary cmos ic unisonic technologies co., ltd 2 of 7 www.unisonic.com.tw qw-r502-923.a ? pin configuration ? pin description pin no. pin name description 1 v33 3.3v ovp/uvp input 2 v5 5v ovp/uvp input 3 v12 12v ovp/uvp input 4 pt extra ovp protection input 5 gnd gnd 6 rt oscillation frequency by setting external resistor 7 c1 pwm output 1 8 c2 pwm output 2 9 rem remote on/off input rem=?low? means the main smps is turned-on rem=?high? means the main smps is turned-off 10 ss soft start function by setting external capacitor 11 pg power good signal pg=?high? means ?power good? pg=?low? means ?power fail? 12 det power good signal detection input 13 v cc power 14 opout op amp output 15 opnegin op amp negative input 16 vadj op compensation positive input
3520 preliminary cmos ic unisonic technologies co., ltd 3 of 7 www.unisonic.com.tw qw-r502-923.a ? block diagram v33 v5 v12 pt rem det rt vadj opnegin opout pg ss c1 c2 uv uv - + - + uv - + ov - + ov - + ov - + ov - + - + - + + - 0.62v ovp uvp 110us 280ms delay in out clr 510us s q r qout 5k 280ms delay in out v ss d q c qn pwm control pwmcmp detcmp soft_start controller + - + - osc clr remonf remon 4.5ms delay 36ms delay 0.62v 2.45v error amp
3520 preliminary cmos ic unisonic technologies co., ltd 4 of 7 www.unisonic.com.tw qw-r502-923.a ? absolute maximum rating (v cc =5.5v) parameter symbol ratings unit supply voltage v cc 5.5 v drain output voltage v cc 1, v cc 25.5 v drain output current i cc 1, i cc 2 200 ma power dissipation p d 200 mw operating temperature t opr -10~+70 c storage temperature t stg -65~+150 c note: absolute maximum ratings are those values be yond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. ? electrical characteristics (t a =25c, v cc =5v) parameter symbol test conditions min typ max unit dead time control section input threshold voltage v thdt zero. duty cycle 3.0 3.3 v max. duty cycle 0.1 v error amp section close loop voltage gain g vc 0.5v~3.5v 65 db cross over point 0db 320 khz opneg bias voltage opneg open 2.38 2.45 2.52 v output section output saturation voltage v dssat i d =200ma 1.3 1.5 v drain off-state current i doff v cc =v d =v s =0v 2 10 a rising time t r 100 200 ns falling time t f 50 200 ns protection section over voltage protection (ovp) v33 3.8 4.1 4.3 v v5 5.8 6.2 6.6 v v12 4.41 4.64 4.90 v pt 1.1 1.25 1.3 v under voltage protection (uvp) v33 1.78 1.98 2.18 v v5 2.70 3.00 3.30 v v12 2.11 2.37 2.63 v uvp disable voltage pt 0.55 0.62 0.68 v uvp delay time t dly 100 280 500 ms remote on/off section rem high input voltage v ih 2.0 v rem low input voltage v il 0.8 v rem pull high voltage v h ( pull ) 2.0 5.25 v rem delay time t dly 30 36 42 ms rem off delay time t dly (off) 3.5 4.5 5.5 ms power good section detecting input voltage v i ( det ) 0.55 0.62 0.68 v pg output pull-up resistor r o ( pull-up )) 5 k ? pg output load resistor r o ( load ) 0.5 1 2 k ? pg delay time 150 280 350 ms output saturation voltage v o ( sat ) i pg =10ma 0.2 0.4 v soft start section source current of ss i ss 28 33 38 a total device standby supply current i cc 10 20 ma oscillation section oscillation frequency f osc rt=75k ? 55 60 65 khz
3520 preliminary cmos ic unisonic technologies co., ltd 5 of 7 www.unisonic.com.tw qw-r502-923.a ? function description (1) remote on/off rem remonf remon trem trem toff toff (2) under voltage protection delay time rem remonf uvp trem td,uvp (3) protection control of the soft-start the soft-start function is to reduce the large current surge during power-up or pr eventing the output voltages (v33/v5/v12) reaches the over voltage protection level. (4) the function of pt this signal is prepared for extra over voltage protection input (v pt >1.25v) or another disable under voltage protection function (v pt <0.62v).
3520 preliminary cmos ic unisonic technologies co., ltd 6 of 7 www.unisonic.com.tw qw-r502-923.a ? function description(cont.) (5) pulse width modulation block the output pulse width modulation is generated by comparison of the saw-t ooth waveform from the capacitor c t to the feedback of the voltage. therefore, an increase in feedback cont rol signal amplitude causes a linear decrease of the output pulse width. also, the ss (dtc and soft-start) lim its the output pulse width. the ti ming diagram is shown as below: (6) in some application power system, adding an external re sistor (r9) could reduce the peak value spike from the environments to pin 9 (rem) and avoid pin 9 (rem) damaged by the external noise. ? typical application circuit r10 r11
3520 preliminary cmos ic unisonic technologies co., ltd 7 of 7 www.unisonic.com.tw qw-r502-923.a utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
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