The LM2576 series voltage regulator is a monolithic integrated circuit that provides all the active functions of a step-down (step-down) switching regulator, capable of driving 3A loads with excellent line and load regulation. These devices are available in fixed output voltage and adjustable output versions of 3.3V, 5V, 12V, and 15V. These regulators require a minimum number of external components and are simple to use, including internal frequency compensation and fixed frequency oscillators.
The LM2576 series provides an efficient alternative to the popular three-terminal linear voltage regulator. It greatly reduces the size of heat sinks and in some cases does not require heat sinks. A standard series of inductors optimized for LM2576 is available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies.
Additional features include a guaranteed tolerance of ±4% of the output voltage at specified input voltage and output load conditions, and a tolerance of ±10% of the oscillator frequency. Including external shutdown, with 50 μA (typical) standby current. Output switches include cycle term flow and thermal shutdown for full protection under failure conditions.
Pin Assignments
Typical application
Block Diagram
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 3A output current
● Wide input voltage range, 40V up to57V for HV version
● Requires only 4 external components
● 52 kHz fixed frequency oscillator
● TTL shutdown capability, low power standby mode
● High efficiency
● Uses readily available standard inductors
● Thermal shutdown and current limit protection
Applications
● Simple and efficient step-down regulator
● High efficiency preregulator of linear voltage regulator
● Switch regulator on card
● Positive - negative converter (Buck-Boost)
