资 源 简 介
The LM1577/LM2577 are monolithic integrated circuits thatprovide all of the power and control funcTIons for step-up(boost), flyback, and forward converter switching regulators.The device is available in three different output voltageversions: 12V, 15V, and adjustable.Requiring a minimum number of external components, theseregulators are cost effecTIve, and simple to use. Listed in thisdata sheet are a family of standard inductors and flybacktransformers designed to work with these switching regulators.Included on the chip is a 3.0A NPN switch and its associatedprotecTIon circuitry, consisTIng of current and thermal limiting,and undervoltage lockout. Other features include a 52 kHzfixed-frequency oscillator that requires no external components,a soft start mode to reduce in-rush current duringstart-up, and current mode control for improved rejection ofinput voltage and output load transients.Featuresn Requires few external componentsn NPN output switches 3.0A, can stand off 65Vn Wide input voltage range: 3.5V to 40Vn Current-mode operation for improved transientresponse, line regulation, and current limitn 52 kHz internal oscillatorn Soft-start function reduces in-rush current during start-upn Output switch protected by current limit, under-voltagelockout, and thermal shutdownTypical Applicationsn Simple boost regulatorn Flyback and forward regulatorsn Multiple-output regulator
