August 2004

1

MIC4826

MIC4826

Micrel

MIC4826

Low Input Voltage, 160V

Final Information

General Description

Micrel’s MIC4826 is a high output voltage, DC to AC con-

verter, designed for driving EL (Electroluminescent) lamps.

The device operates from an input voltage range of 1.8V to

5.5V, making it suitable for 1-cell Li Ion and 2- or 3-cell

alkaline/NiCad/NiMH battery applications. The MIC4826 con-

verts a low voltage DC input to a 160V

drives the EL lamp.

The MIC4826 is comprised of two stages: a boost stage, and

an H-bridge, lamp driver, stage. The boost stage steps the

input voltage up to +80V. The H-bridge stage then alternately

switches the +80V output to each terminal of the EL lamp,

thus creating a 160V

generate light.

The MIC4826 features separate oscillators for the boost- and

H-bridge stages. External resistors independently set the

operating frequency of each stage. This flexibility allows the

EL lamp circuit to be optimized for maximum efficiency and

brightness.

The MIC4826 uses a single inductor and a minimum number

of external components, making it ideal for portable, space-

sensitive applications.

The MIC4826 is available in an 8-pin MSOP package with an

ambient temperature range of –40

°C to +85°C.

Typical Application

Features

• 1.8V to 5.5V DC input voltage

• 160V

• Independently adjustable EL lamp frequency

• Independently adjustable boost converter frequency

• 0.1

µA shutdown current

Applications

• LCD panel backlight

• Cellular phones

• PDAs

• Pagers

• Calculators

• Remote controls

• Portable phones

Ordering Information

Part Number

Temp. Range

Package

Standard

Pb-Free

MIC4826BMM MIC4826YMM –40

°C to +85°C MSOP-8

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000• http://www.micrel.com

High Voltage EL Driver

442k

2M

0.01

µF/100V

D1

1N4148

L1

220

µH

15

6

8

7

2

3

4

SW

CS

VA

VB

VDD

RSW

REL

GND

MIC4826

10

µF

TIME (2ms/div)