unisonic technologies co., ltd p1580 linear integrated circuit www.unisonic.com.tw 1 of 6 copyright ? 2010 unisonic technologies co., ltd qw-r103-049.a 380khz, 2.5a step-down switching regulator ? description the utc p1580 is a current mode, pwm controller with 380khz fixed frequency. it achieves 2.5a continuous output current over a wide input supply range with excellent load and line regulation. by using an external compensation pin, this device offers user flexibility in determining loop dynamic. the utc p1580 integrates control, monitor and protection functions to provide a low cost and perfect power solution. the device provides 3.5 to 28v wide range operating input and high-efficiency up to 90%. an under- voltage-lock-output (u vlo) circuit monitors the supply voltage to prevent from wrong logic control. an internal 1.222v reference voltage provides low output voltage down to 1.22v for further applications. the over-c urrent protection of controller monitors the output current by using the voltage drop across a current sensing resistor. additional under voltage protection monitors the voltage on fb pin for s hort-circuits protection. the utc p1580 provides fast transient response and requires very few external devices for operation. ? features * 2.5a output current * 380khz frequency of operation * 3.5v to 28v input voltage range * 5 a shutdown supply current * output adjustable from 1.22 to 21 * frequency feedback at short circuit * thermal shutdown * under voltage lock output * current mode with low esr output ceramic capacitors * up to 90% efficiency * frequency synchronization input ? ordering information ordering number package packing P1580G-SH2-R hsop-8 tape reel
p1580 linear integrated circuit unisonic technologies co., ltd 2 of 6 www.unisonic.com.tw qw-r103-049.a ? pin configuration 1 bs 2 in 3 sw 8 sync 7 en 6 comp 5 fb gnd 4 ? pin description pin no. pin name description 1 bs supply pin to the power transistor driver. tie to external circuit to generate a local supply voltage higher than the input volt age in order to fully turn on the internal power transistor. 2 in power supply pin. 3 sw power switch output pin. 4 gnd ground pin. 5 fb the output voltage feedback pin. it is also the inverting input of the error amplifier. 6 comp compensation pin. it is also the output of the internal error amplifier. (1). a rc network at this pin compensates the control loop. (2). the voltage at this pin controls t he peak current of the internal switch. 7 en regulator on/off control pin. leave en unconn ected if unused. a low input at en turns on the converter, and a hi gh input turns it off. 8 sync synchronization input - the sync pin is used to synchronize the internal oscillator to an external signal.
p1580 linear integrated circuit unisonic technologies co., ltd 3 of 6 www.unisonic.com.tw qw-r103-049.a ? block diagram - - + - + s r q + reference 45k-380khz slope comp in bs comp fb en sync pwm ea driver power transistor rsense 1.22v uvlo otp uvlo sw gnd 4 3 2 7 5 6 8 1
p1580 linear integrated circuit unisonic technologies co., ltd 4 of 6 www.unisonic.com.tw qw-r103-049.a ? absolute maximum rating (note 3) parameter symbol ratings unit supply voltage v in 28 v switch voltage v sw -1~ v in +1 v boost voltage v bs v sw +6 v feedback voltage v fb -0.3~6 v enable/uvlo voltage v en -0.3~6 v compensation voltage v comp -0.3~6 v synchronization voltage v sync -0.3~6 v junction temperature t j 150 c storage temperature t stg -65~+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. ? recommended operating conditions (note 1) parameter symbol ratings unit input voltage v in 3.5~28 v ambient operating temperature t a -40 ~ +125 c note: the device is not guaranteed to function outside its operating rating. ? thermal data (note 1) parameter symbol ratings unit junction to ambient ja 105 c/w junction to case jc 50 c/w note: measured on approximately 1? square of 1 oz. copper surrounding device leads. ? electrical characteristics (v in =12v, t a =25c, unless otherwise specified) parameter symbol test conditions min typ max unit feedback voltage v fb 7v v in 25v, v comp < 2v 1.198 1.222 1.246 v upper switch leakage v en =0v, v sw =0v 0.1 10 a current limit i limit 3.1 3.3 3.3 a current limit gain. output current to comp pin voltage g comp 2.2 a/v error amplifier voltage gain a vea 400 v/v error amplifier transconductance g ea i c =10 a 680 770 1000 a/v oscillator frequency f osc 342 380 418 kh z short circuit frequency f sc v fb =0v 40 46 54 kh z synchronization frequency f sync sync drive 0 ~ 2.7v 370 660 kh z maximum d max v fb =1.0v 90 % duty cycle minimum d min v fb =1.5v 0 % switch v cesat i sw =2a 400 mv enable threshold v en i cc > 100 a 0.9 1.1 1.3 v enable pull up current i en v en =0v 0.1 a shutdown i shdn v en 0.4v 5 8 a supply current quiescent i q v en 2.6v; v fb =1.4v 1.7 ma current of short circuit i sc v in =10v 1.8 a thermal shutdown t otp 160 c note: if the v in voltage exceeding 23v under short circuit condition, there will be some risk.
p1580 linear integrated circuit unisonic technologies co., ltd 5 of 6 www.unisonic.com.tw qw-r103-049.a ? typical application circuit if the load current is applied in 2a, the input voltage can range from 7 to 28v . if the load current is applied in 2a, the input voltage can range from 4.4 to 28v.
p1580 linear integrated circuit unisonic technologies co., ltd 6 of 6 www.unisonic.com.tw qw-r103-049.a ? typical characteristics sw sw efficiency (%) efficiency (%) 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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