The LM2591HV series operates at a switching frequency

of150 kHz thus allowing smaller sized filter com-pontents

than what would be needed with lower frequency switching

regulators. Available in a standard 5-lead TO-220 package

with several different lead bend options, and a 5-lesd

TO-263 surface mount package.

The LM2591HV series of regulators are monolithicintegrated

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, and an

adjustable output version.

General Description

Requiring a minimum number of external components, these

regulators are simple to use and include internal frequency

compensation†, and a fixed-frequency oscillator.

A standard series of inductors are available from several

different manufacturers optimized for use with the LM2591

series. This feature greatly simplifies the design of

switch-mode power supplies.

Other features include a guaranteed ±4 tolerance on output

voltage under specified input voltage and output load

conditions, and ±15 on the oscillator frequency. External

shutdown is included, featuring typically 80 μA standby current.

Self protection features include a two stage frequency

reducing current limit for the output switch and an over

temperature shutdown for complete protection under fault

conditions.

Available in TO-220 and TO-263 packages

(57V for HV version)

Features

n 3.3V, 5V, 12V, and adjustable output versions

n Adjustable version output voltage range, 1.2V to 57V

±4 max over line and load conditions

n

n Guaranteed 1A output load current

n Input voltage range up to 60V

n Requires only 4 external components

n Excellent line and load regulation specifications

n 150 kHz fixed frequency internal oscillator

n TTL shutdown capability

n Low power standby mode, IQ typically 80 μA

n High efficiency

n Uses readily available standard inductors

n Thermal shutdown and current limit protection

Applications

n Simple high-efficiency step-down (buck) regulator

n On-card switching regulators

n Positive to negative converter