The LM2575 /LM2575HV series operates at a switching

frequency of 52 kHz thus allowing smaller sized filter compontents

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-262 surface mount package.

The LM2575 /LM2575HV series of regulators are monolithic

integrated circuits that provide all the active functions for a

step-down (buck) switching regulator, capable of driving a 2A

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

LM2575series. 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 cur-rent. 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,TO-220B packages

(57V for HV version)

特性 Features

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

n Adjustable version output voltage range, 1.2V to 37V

±4 max over line and load conditions

n

n Guaranteed 2A output load current

n Input voltage range up to 40V

n Requires only 4 external components

n Excellent line and load regulation specifications

n 52 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

Note: ?Patent Number 5,382,918.