LM1575 Datasheet | National Semiconductor

Description The LM2575 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, 15V, and an adjustable output version. Requiring a minimum number of external ponents, these regulators are simple to use and include internal frequency pensation and a fixed-frequency oscillator. The LM2575 series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in many cases no heat sink is required. A standard series of inductors optimized for use with the LM2575 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies. Other features include a guaranteed ±4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring 50 μA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions. Features - 3.3V, 5V, 12V, 15V, and adjustable output versions - Adjustable version output voltage range, 1.23V to 37V (57V for HV version) ±4% max over line and load conditions - Guaranteed 1A output current - Wide input voltage range, 40V up to 60V for HV version - Requires only 4 external ponents - 52 k Hz fixed frequency internal oscillator - TTL shutdown capability, low power standby mode - High efficiency - Uses readily available standard inductors - Thermal shutdown and current limit protection - P+ Product Enhancement tested Applications - Simple high-efficiency step-down (buck) regulator - Efficient pre-regulator for linear regulators - On-card switching regulators - Positive to negative converter (Buck-Boost) Typical...