The LM1577/LM2577 are monolithic integrated circuits that provide 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 voltage versions: 12V, 15V, and adjustable.
Requiring a minimum number of external components, these regulators are cost effective,
and simple to use. Listed in this data sheet are a family of standard inductors and flyback
transformers designed to work with these switching regulators.
Included on the chip is a 3.0A NPN switch and its associated protection circuitry,
consisting of current and thermal limiting, and undervoltage lockout. Other features include a 52
kHz fixed-frequency oscillator that requires no external components, a soft start mode to reduce
in-rush current during start-up, and current mode control for improved rejection of input voltage
and output load transients.