unisonic technologies co., ltd uc4601 preliminary cmos ic www.unisonic.com.tw 1 of 4 copyright ? 2011 unisonic technologies co., ltd qw-r502-494.c pwm step-down dc-dc controller ? description the utc uc4601 is a pwm step-down dc/dc controller. it has a low supply current. the step-down dc/dc converter with low ripple, high efficiency performance is conveniently configured with additional external components, such as a power-transistor, an inductor, a diode and capacitors. the output voltage can be adjusted with external components. the utc uc4601 contains a high precision band-gap voltage reference, a pwm control circuit, a soft-start circuit, a protection circuit, an oscillator, an error amplifier with built-in compensation network and input/output voltage detection circuits. the utc uc4601 based dc/dc converter can performance well when maintaining stability, which is due to its built-in state-of-art control algorithm. further, if the term of maximum duty cycle retains on a certain time, the embedded pr otection circuits restart the operation with soft-start and repe at until the maximum duty cycle condition is released. finally, the internal uvlo function blocks potentially unstable output when t he input voltage reaches the uvlo threshold or less. this is aiming at making this circuit standby for low power consumption. the utc uc4601 can be applied in battery-powered equipment, hand-held communication equipment, cameras, video instruments such as vcrs, camcorders, household electrical appliances. ? features * 500kh z oscillation frequency * input voltage varies from 2.3v to 18v * low temperature coefficient of output voltage: typ. 100ppm/c * internal soft-start and protection function * high efficiency up to 90% (typ.) * high output voltage accuracy: 2% * standly current: 0.1 a (typ.) * cmos output capability ? ordering information ordering number package packing lead free halogen free UC4601L-AF5-R uc4601g-af5-r sot-25 tape reel uc4601l - af5 - r (1) packing type (2) package type (3) lead free (1) r: tape reel (2) af5: sot-25 (3) g: halogen free, l: lead free
uc4601 preliminary cmos ic unisonic technologies co., ltd 2 of 4 www.unisonic.com.tw qw-r502-494.c ? marking 3 2 1 uj46 5 4 g: halogen free l : lead free ? pin configuration ? pin description pin no pin name description 1 ce chip enable. active with ?h? 2 gnd ground 3 v fb feedback voltage 4 ext external transistor driver pin (cmos output) 5 v in power input voltage
uc4601 preliminary cmos ic unisonic technologies co., ltd 3 of 4 www.unisonic.com.tw qw-r502-494.c ? absolute maximum rating parameter symbol ratings unit v in supply voltage v in 20 v ext pin output voltage v ext -0.3 ~ v in +0.3 v ce pin input voltage v ce -0.3 ~ v in +0.3 v v out /v fb pin input voltage v out /v fb -0.3 ~ 6 v ext pin output current i ext 50 ma power dissipation p d +250 mw operating temperature t opr -40 ~ +85 c storage temperature t stg -55 ~ +125 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. ? operating range parameter symbol ratings unit v in supply voltage v in 2.5 ~ 18 v ext pin output voltage v ext -0.3 ~ v in +0.3 v ce pin input voltage v ce -0.3 ~ v in +0.3 v v out /v fb pin input voltage v out /v fb -0.3 ~ 5.5 v ext pin output current i ext 50 ma ? electrical characteristics (t opr =25c, unless otherwise specified) parameter symbol test conditions min typ max unit adjustable output voltage type operating voltage v in 2.3 18 v feedback voltage v fb v in =v ce =8v, i load =350ma 0.98 1.00 1.02 v feedback voltage temperature coefficient v fb / t -40c uc4601 preliminary cmos ic unisonic technologies co., ltd 4 of 4 www.unisonic.com.tw qw-r502-494.c ? typical application circuit adjustable output voltage type. for example, output voltage=3.3v 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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