MIC4801

High Efficiency 600mA Single Channel

Linear WLED Driver with

Ultra Fast PWM™ Control

Ultra Fast PWM is a trademark of Micrel, Inc.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

January 2011

M9999-011811-A

General Description

The MIC4801 is a high efficiency White LED (WLED)

driver designed to drive a single LED up to 600mA. The

MIC4801 constant current driver is designed to drive high

power LED’s in various lighting applications. The MIC4801

provides the highest possible efficiency as this architecture

has no switching losses present in traditional charge

pumps or inductive boost circuits. It features a typical

dropout of 130mV at 400mA. This allows the LEDs to be

driven directly from the voltage source eliminating

switching noise/losses present with the use of boost

circuitry. The high accuracy (±1% typical) current regulated

WLED channel ensures uniform display illumination under

all conditions. The brightness is controlled through an Ultra

Fast PWM™ Control interface operating down to less than

1% duty cycle.

The MIC4801 is available in an 8-pin SOIC package with a

junction temperature range of -40

°C to +125°C.

Datasheets and support documentation can be found on

Features

• High Efficiency (no Voltage Boost losses)

• Ultra Fast PWM™ control (200Hz to 500kHz)

• Input voltage range: 3.0V to 5.5V

• Dropout of 130mV at 400mA

• Programmable LED current with external resistor

• Current accuracy of ±1% typical

Applications

• Bill board displays

• Marquee displays

• Instrument displays

• Architectural lighting

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Typical Application

High Current Lighting Schematic