1FEATURES

2• Inverting and Non-Inverting Feedback Inputs

• 1.0V Reference at Inputs

• Operates from Supply Voltages of 2V to 40V

• Output Current up to 750 mA, Saturation Less

than 0.9V

• Current Limit and Thermal Shut Down

• Duty Cycle up to 90%

APPLICATIONS

• Switching Regulators in Buck, Boost,

Inverting, and Single-Ended Transformer

Configurations

• Motor Speed Control

• Lamp Flasher

DESCRIPTION

The LM2578A is a switching regulator which can

easily be set up for such DC-to-DC voltage

conversion circuits as the buck, boost, and inverting

configurations. The LM2578A features a unique

comparator input stage which not only has separate

pins for both the inverting and non-inverting inputs,

but also provides an internal 1.0V reference to each

input, thereby simplifying circuit design and p.c. board

layout. The output can switch up to 750 mA and has

output pins for its collector and emitter to promote

design flexibility. An external current limit terminal

may be referenced to either the ground or the Vin terminal, depending upon the application. In addition,

the LM2578A has an on board oscillator, which sets

the switching frequency with a single external

capacitor from <1 Hz to 100 kHz (typical).

The LM2578A is an improved version of the LM2578,

offering higher maximum ratings for the total supply

voltage and output transistor emitter and collector

voltages.