unisonic technologies co., ltd ucsr3602s preliminary cmos ic www.unisonic.com.tw 1 of 9 copyright ? 2015 unisonic technologies co., ltd qw-r129-016.a dip-7a high precision cc/cv primary-side pwm power switch ? description the utc ucsr3602s is a primary control switch mode charger and adapter applications . the controlled variable is transferred by an auxiliary winding from the secondary to the primary side. the device integrat es pwm controller to enhance the performance of discontinuous conduction mode (dcm) flyback converters. the utc ucsr3602s operates in primary-side sensing and regulation. opto-coupler and tl431 could be eliminated. it also provides off-time modulation to linearly decrease pwm frequency under light-load conditions so t hat low standby power can be achieved. the utc ucsr3602s achieves high precision cv/cc regulation and high power efficiency. it offers comprehensive protection coverage with auto-recovery features including cycle-by-cycle current limiting, v dd over voltage protection, v dd clamp, otp, leading edge blanking, v dd under voltage lockout, etc. ? features * high voltage startup circuit * built-in 600v power mosfet * 5% constant voltage regulation at universal ac input * high precision constant current r egulation at universal ac input * primary side control without tl431 and opto-coupler * programmable cv and cc regulation * programmable cable compensation in cv mode * flyback topology in dcm operation * frequency hopping to reduce system emi * built-in leading edge blanking * built-in primary winding inductance compensation * power on soft start * gate output maximum voltage clamped at 15v * cycle-by-cycle current limiting * over voltage protection * v dd under-voltage lockout ? ordering information ordering number lead free halogen free package packing UCSR3602SL-D07A-T ucsr3602sg-d07a-t dip-7a tube
ucsr3602s preliminary cmos ic unisonic technologies co., ltd 2 of 9 www.unisonic.com.tw qw-r129-016.a ? marking ? pin configuration ? pin description pin no. pin name description 1 v dd power supply 2 comp loop compensation 3 inv the voltage feedback from the auxiliary winding 4 cs current sense input 5, 6 drain power mosfet drain pin 7 gnd ground
ucsr3602s preliminary cmos ic unisonic technologies co., ltd 3 of 9 www.unisonic.com.tw qw-r129-016.a ? block diagram
ucsr3602s preliminary cmos ic unisonic technologies co., ltd 4 of 9 www.unisonic.com.tw qw-r129-016.a ? absolute maximum rating parameter symbol ratings unit drain voltage (off state) b vdss -0.3 ~ bvdss v v dd zener clamp continuous current i dd 10 ma comp voltage v comp -0.3 ~ 7 v cs input voltage v cs -0.3 ~ 7 v inv input voltage v inv -0.3 ~ 7 v operating junction temperature t j -20 ~ 150 c storage temperature t stg -55 ~ 150 c note: absolute maximum ratings are those values beyond which the device could be permanently damaged. absolute maximum ratings are stress ratings only and functional device oper ation is not implied. ? thermal characteristics parameter symbol ratings unit junction to ambient ja 75 c/w ? output power table parameter ratings unit 230vac15% 14 w adapter (note 1) 85-264vac 12 w
ucsr3602s preliminary cmos ic unisonic technologies co., ltd 5 of 9 www.unisonic.com.tw qw-r129-016.a ? electrical characteristics (t a =25c, v dd =15v, unless otherwise specified) parameter symbol test conditions min typ max unit startup section startup voltage v st v dd ucsr3602s preliminary cmos ic unisonic technologies co., ltd 6 of 9 www.unisonic.com.tw qw-r129-016.a ? operation description the utc ucsr3602s is a primary control switch mode char ger and adapter applications. it operates in primary-side sensing and regulation. opto-coupler and tl43 1 could be eliminated. proprietary built-in cv and cc control can achieve high precision cv /cc performance. the devic e integrates pwm controller to enhance the performance of discontinuous conduction mode (dcm) flyback converters. startup control the v dd pin of utc ucsr3602s is connected to the line input through a resistor. a large value startup resistor can be used to minimize the power loss in application because the st art current of utc ucsr3602s is very low. when the v dd voltage reaches v th(on) , the internal startup circuit is disabled and the ic turns on. operating current the operating current of utc ucsr3602s is as low as 1.6ma. good effici ency and very low standby power can be achieved. constant voltage operation the output voltage is defined by the transmission ratio between the secondary and auxiliary winding. the utc ucsr3602s captures the auxiliary winding feedback voltage at in v pin and operates in constant-voltage (cv) mode to regulate the output voltage. the auxiliary voltage reflects the output voltage is given by: v ? + v n n = v o s a aux (1) where v indicates the drop vo ltage of the output diode. figure 2. auxiliary voltage waveform via a resistor divider connected betwe en the auxiliary winding and inv, the v aux is sampled at the tsampling end and it is hold until the next sampling. the sampled voltage is compared with 2. 0v reference voltage and the error is amplified. the error amplifier output reflec ts the load condition and controls the t off time and the ipk to regulate the output voltage, thus constant output volt age can be achieved.
ucsr3602s preliminary cmos ic unisonic technologies co., ltd 7 of 9 www.unisonic.com.tw qw-r129-016.a ? operation description (cont.) constant current operation when the sampled voltage is below 2.0v reference volt age and the error amplifier output reaches its maximum, thus utc ucsr3602s operates in constant-curr ent (cc) mode. the cc point a nd maximum output power can be externally adjusted by external current sense resistor r cs. the larger rcs, the sma ller cc point is, and the smaller output power becomes. i out v out large rcs small rcs figure 3. adjustable output power by changing r cs figure 4. secondary current waveform in cc operation, the cc loop control function of utc ucsr3602s will keep a fixed proportion between secondary inductance de-magnetization time (tdemag) and switch ing cycle time (tsw). the fixed proportion is 2 1 = tsw tdemag (2) thus the output current is given by: pk pk out i s n p n 4 1 tsw tdemag i s n p n 2 1 i ? ? ? ? ? ? ? (3) programmable cable drop compensation utc ucsr3602s has a built-in cable voltage drop compensation to achieve good load regulation. an offset voltage is generated at inv pin by an internal current flow ing into the resistor divider. the current is inversely proportional to the voltage of comp pin. as a result, it is inversely proportional to the output load current. the voltage drop across the cable is compensated by this offs et voltage at inv pin. it can also be programmed by adjusting the resistance of the divider to com pensate the drop for various cable lines used.
ucsr3602s preliminary cmos ic unisonic technologies co., ltd 8 of 9 www.unisonic.com.tw qw-r129-016.a ? operation description (cont.) current sensing and leading edge blanking cycle-by-cycle current limiting is offered in utc ucsr3602s . the switch current is detected by a sense resistor into the cs pin. when the power switch is turned on, a tu rn-on spike will occur on this resistor. a 900ns leading-edge blanking is built in to avoid false-termi nation of the switching puls e so that the external rc filtering is no longer needed. protection control good power supply system reliability is achieved with its comprehensive protecti on features including v dd over-voltage protection, v dd clamp, gate clamp, power on soft start, cycle-by-cycle current limiting, short circuit protection, leading edge blanking, otp and uvlo, etc. v dd is supplied by transformer auxilia ry winding output. the output of utc ucsr3602s is shutdown when v dd drops below v th(off) and the power converter enters po wer on start-up sequence thereafter.
ucsr3602s preliminary cmos ic unisonic technologies co., ltd 9 of 9 www.unisonic.com.tw qw-r129-016.a ? typical application circuit (5v, 2.4a) bom reference component reference component bd1 bd 2a/600v r1 r 2.4k ? 1206 5% l1 1m h 6x8mm r4 r 200k ? 1206 5% c1 ec 10 f 400v 105c r5 r 18k ? 0805 1% c2 ec 22 f 400v 105c r6 r 3.3k ? 0805 1% c3 ec 4.7 f 50v 105c r7 r 1 ? 1206 5% c4 cc 1nf 1000v 1206 r8 r 1k ? 1206 5% c5 cc 0.1 f 50v 0805 t1 ee-22 c6 ec 2200 f 10v 105c f1 fuse 1a 250vac d1,d2 diode utc 1n4007g cy1 y/c 1000p f 250v d3 diode utc mgbr10s40 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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