The LM2574 series of regulators are monolithic integrated circuits ideally suited for easy and convenient design of a step−down switching regulator (buck converter). All circuits of this series are capable of driving a 0.5 A load with excellent line and load regulation.

These devices are available in fixed output voltages of 3.3 V, 5.0 V, 12 V, 15 V, and an adjustable output version.

These regulators were designed to minimize the number of external components to simplify the power supply design. Standard series of inductors optimized for use with the LM2574 are offered by several different inductor manufacturers.

Features

• 3.3 V, 5.0 V, 12 V, 15 V, and Adjustable Output Versions

• Adjustable Version Output Voltage Range, 1.23 to 37 V ±4 max over Line and Load Conditions

• Guaranteed 0.5 A Output Current

• Wide Input Voltage Range: 4.75 to 40 V

• Requires Only 4 External Components

• 52 kHz Fixed Frequency Internal Oscillator

• TTL Shutdown Capability, Low Power Standby Mode

• High Efficiency

• Uses Readily Available Standard Inductors

• Thermal Shutdown and Current Limit Protection

• NCV Prefix for Automotive and Other Applications Requiring Site and Control Changes

• Pb−Free Packages are Available*

Applications

• Simple and High−Efficiency Step−Down (Buck) Regulators

• Efficient Pre−regulator for Linear Regulators

• On−Card Switching Regulators

• Positive to Negative Converters (Buck−Boost)

• Negative Step−Up Converters

• Power Supply for Battery Chargers