1 Features

1• 3.3-V, 5-V, 12-V, and Adjustable Output Versions

• Adjustable Version Output Voltage Range: 1.2 V

to 37 V ±4% Maximum Over Line and Load

Conditions

• 3-A Output Current

• Available in 7-Pin TO-220 and TO-263 (Surface-

Mount) Package

• Input Voltage Range Up to 40 V

• 150-kHz Fixed-Frequency Internal Oscillator

• Shutdown and Soft-Start

• Out-of-Regulation Error Flag

• Error Output Delay

• Low Power Standby Mode, IQ, Typically 80 μA

• High Efficiency

• Uses Readily Available Standard Inductors

• Thermal Shutdown and Current-Limit Protection

2 Applications

• Simple High-Efficiency Step-Down (Buck)

Regulator

• Efficient Preregulator for Linear Regulators

• On-Card Switching Regulators

• Positive to Negative Converter

3 Description

The LM2599 series of regulators are monolithic

integrated circuits that provide all the active functions

for a step-down (buck) switching regulator, capable of

driving a 3-A load with excellent line and load

regulation. These devices are available in fixed output

voltages of 3.3 V, 5 V, 12 V, and an adjustable output

version.

The LM2598 is a member of the LM259x family, with

additional supervisory and performance features

added.

Requiring a minimum number of external

components, these regulators are simple to use and

include internal frequency compensation, improved

line and load specifications, fixed-frequency oscillator,

Shutdown and Soft-start, error flag delay, and error

flag output.