unisonic technologies co., ltd p1986 linear integrated circuit www.unisonic.com.tw 1 of 6 copyright ? 2011 unisonic technologies co., ltd qw-r103-046.c pwm control 3a step-down converter ? description the utc p1986 consists of 3a step-down switching regulator with pwm control which includes a reference voltage source, oscillation circuit, error amplifier, internal pmos and etc. the utc p1986 can provide low-ripple power, high efficiency, and perfect transient characteristics. the duty ratio varies linearly from 0% to 100% in the pwm control. the error amplifier circuit and soft-start circuit included in this device can prevent overshoot at startup. in ternally, the build-in compensation block can reduce external component count. an enable function, an over current protect (ocp) f unction and short circuit protect (scp) are also build inside, and when ocp happens, the operation frequency will be reduced. in application, the utc p1986 is suitable for portable devices when it works as an ideal power supply in sop-8l package. there is an internal p-channel power mos, a coil, capacitors inside and a diode connected externally that makes these ics step-down switching regulators. ? features * input voltage varies from 3.6v to 28v * output voltage varies from 0.8v to v cc * duty ratio varies from 0% to 100% pwm control * with 330khz typical oscillation frequency * thermal shutdown and scp function and soft-start, current limit, enable function * low esr output capacitor(multi-l ayer chip capacitor) application * built-in switch p-channel power mos * halogen free ? ordering information ordering number lead free halogen free package packing p1986l-s08-r P1986G-S08-R sop-8 tape reel
p1986 linear integrated circuit unisonic technologies co., ltd 2 of 6 www.unisonic.com.tw qw-r103-046.c ? pin configuration 1 2 3 4 8 7 6 5 fb en comp v cc sw sw v ss v ss ? pin description pin no. pin name description 1 fb feedback pin 2 en power-off pin h: normal operation (step-down) l: step-down operation stopped (all circuits deactivated) 3 comp compensation pin 4 v cc ic power supply pin 5 sw switch pin. connect external inductor/diode here. 6 sw switch pin. connect external inductor/diode here. 7 v ss gnd pin 8 v ss gnd pin
p1986 linear integrated circuit unisonic technologies co., ltd 3 of 6 www.unisonic.com.tw qw-r103-046.c ? block diagram en comp v cc sw v ss fb en v ref pwm ss osc driver current limit lateh reference voltage
p1986 linear integrated circuit unisonic technologies co., ltd 4 of 6 www.unisonic.com.tw qw-r103-046.c ? absolute maximum rating (ta=25c, unless otherwise specified ) parameter symbol ratings unit v cc pin voltage v cc v ss -0.3 ~v ss +30 v feedback pin voltage v fb v ss -0.3 ~ v cc v on/off pin voltage v en v ss - 0.3 ~ v cc + 0.3 v switch pin voltage v sw v ss - 0.3 ~ v cc + 0.3 v operating supply voltage v op +3.6 ~ 28 v power dissipation p d internally limited mw storage temperature t stg -40 ~ +150 c operating temperature t opr -20 ~ +125 c note: absolute maximum ratings are those values beyo nd which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. ? thermal data parameter symbol ratings unit junction to ambient ja 70 /w junction to case jc 25 /w notes: ja is measured with the pcb copper area(need connect to sw pins) of approximately 1 in2(multi-layer) ? electrical characteristics (v in = 12v, ta= 25c, unless otherwise specified.) parameter symbol test conditions min typ max unit feedback voltage v fb i out =0.2a 0.784 0.80 0.816 v feedback bias current i fb(bias) i out =0.1a 0.1 0.5 a switch current i sw pear current, no outside circuit v fb =0v force driver on 4 a standby current i stn-by v en =0v no outside circuit v fb =0v force driver on 2 10 a quiescent current i q v fb =1.2v force driver off 3 5 ma oscillation frequency f osc measure waveform at sw pin 260 330 400 khz frequency of current limit or short circuit protect f osc1 measure waveform at sw pin 40 khz line regulation out out v v v cc =5v-28v, i out =0.2a 0.4 % load regulation out out v v i out =0.2a-3a 0.3 % i sh v en =2.5v(on) 5 a en pin input current i sl v en =0.3v(off) 0 a soft-start time t ss 0.3 3.5 8 ms v cc =5v,v fb =0v 130 150 m ? internal mosfet r ds(on) r ds(on) v cc =12v,v fb =0v 80 100 m ? v sh high(regulator on) 1.6 v en pin logic input threshold voltage v sl low(regulator off) 0.8 v thermal shutdown temp tsd 140 c
p1986 linear integrated circuit unisonic technologies co., ltd 5 of 6 www.unisonic.com.tw qw-r103-046.c ? typical application circuit mlcc v cc (v) c1 (nf) c4 ( f) c7 (nf) c8 ( f) r3 (k ? ) 7 1 33 2.2 0.1 10.3 12 1 33 2.2 0.1 10.96 19 1 33 10 0.1 5.94
p1986 linear integrated circuit unisonic technologies co., ltd 6 of 6 www.unisonic.com.tw qw-r103-046.c ? typical characteristics output voltage (mv) time (2 s/div) 01020 0 20 0 -200 200 time (10 s/div) 0 50 100 0 20 sw sw v cc =19v, v out =5v, i out =3a v cc =19v, v out =0v 70 80 90 100 0 0.5 1.0 1.5 2.0 2.5 3.0 60 50 40 load current, i load (a) efficiency (%) efficiency vs. load current v cc =7v v cc =12v v cc =19v v out =5v 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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