IMP525

IMP525

Sing

ed

Electr

p

Dr

er

x

Audio/TV remote control units

x

Pagers/Cellular phones

x

PDAs

x

Clocks and radios

x

Portable GPS receivers

x

LCD modules

x

Toys

x

Wide operating voltage range - from 0.9V to 2.5V

x

Simple design requires few passive components

x

112V peak-to-peak typical AC output voltage

x

Adjustable output frequency controls lamp

color and power consumption

x

Adjustable converter frequency minimizes

circuit power consumption

x

Disable mode extends battery life

x

Disable current under 2

µA

x

Compact MicroSO package option

Key Features

Applications

Block Diagram

–

+

525_01.eps

1

4

3

7

6

2

Switch

Oscillator

Regulation

Control

IMP525

Bridge

Output

Driver

Q

Q

Q

Lamp Drive

Oscillator

C

GND

5

8

Q

The IMP525 is an Electroluminescent (EL) lamp driver designed for sys-

tems that must operate below 1 volt. The input supply voltage range is

0.9V to 2.5V. Typical output lamp drive voltage is 112V. All four EL lamp-

driving functions are on-chip. These are the switch-mode power supply,

its high-frequency oscillator, the high-voltage H-bridge lamp driver and

its low-frequency oscillator. EL lamps of up to 6nF capacitance can be dri-

ven to high brightness.

The circuit requires few external components; one inductor, one diode,

one capacitor and two resistors. The resistors set the frequency for the

two oscillators.

A disable mode puts the chip into a low current-drain state. When dis-

abled, quiescent current drops to 2

resistors, to ground. A disable pad, accessible only on the die, can also be

used to disable the driver.

An internal circuit shuts down the switching regulator when the lamp

drive voltage exceeds 112V peak-to-peak. This conserves power and

extends battery life.

The IMP525 is available in MicroSO and SO-8 packages and in die form.

IMP, Inc.

San Jose, CA

408-432-9100/www.impweb.com