National Semiconductor LM2585 Simple Switcher 3A Flyback Regulator Datasheet

About this manual

The LM2585 series are monolithic switching regulators designed for flyback, boost and forward converter topologies. The device is offered in four output‑voltage versions (3.3 V, 5.0 V, 12 V and adjustable) and requires only a few external components.

Key features include a 3 A NPN output switch that can stand off 65 V, a fixed 100 kHz oscillator, wide input range (4 V‑40 V), soft‑start, current‑mode control and a guaranteed +4 % output‑voltage tolerance.

What's inside

• General Description
• Features
• Typical Applications
• Electrical Characteristics
• Absolute Maximum Ratings
• Ordering Information
• Physical Dimensions
• Block Diagram
• Test Circuits
• Life Support Policy

Specifications

Frequently asked questions

What is the fixed switching frequency of the LM2585?

The LM2585 operates at a fixed 100 kHz switching frequency.

What output‑voltage options are available for the LM2585?

The regulator is offered in 3.3 V, 5.0 V, 12 V and an adjustable version.

What is the maximum current the LM2585 output switch can handle?

The NPN output switch can handle up to 3 A and stand off up to 65 V.

What input voltage range does the LM2585 support?

It supports an input voltage from 4 V to 40 V.