LM2577 Datasheet | National Semiconductor

Description 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 ponents, 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 k Hz fixed-frequency oscillator that requires no external ponents, 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. Features Requires few external ponents NPN output switches 3.0A, can stand off 65V Wide input voltage range: 3.5V to 40V Current-mode operation for improved transient response, line regulation, and current limit n 52 k Hz internal oscillator n Soft-start function reduces in-rush current during start-up n Output switch protected by current limit, under-voltage lockout, and thermal shutdown n n n n Typical Applications n Simple boost regulator n Flyback and forward regulators n Multiple-output regulator Typical Application DS011468-1 Note: Pin numbers shown are for TO-220 (T) package. Ordering Information Temperature Range - 40˚C ≤ TA ≤ +125˚C Package Type 24-Pin Surface Mount 16-Pin Molded DIP 5-Lead Surface Mount 5-Straight Leads 5-Bent Staggered Leads - 55˚C ≤ TA ≤ +150˚C 4-Pin TO-3 Output Voltage 12V LM2577M-12 LM2577N-12 LM2577S-12 LM2577T-12 LM2577T-12 Flow LB03 15V LM2577M-15 LM2577N-15 LM2577S-15 LM2577T-15 LM2577T-15 Flow LB03 ADJ LM2577M-ADJ LM2577N-ADJ LM2577S-ADJ LM2577T-ADJ LM2577T-ADJ Flow LB03 LM1577KADJ/883 K04A TO-3 NSC Package Package...