© 2000 IMP, Inc.

408-432-9100/www.impweb.com

1

IMP52

7

Sing

ed

Electr

p

Dr

er

N Audio/TV remote control units

N Pagers/Cellular phones

N PDAs

N Clocks and radios

N Portable GPS receivers

N LCD modules

N Toys

N Wide operating voltage range - from 0.9V to 2.5V

N Simple design requires few passive components

N 180V peak-to-peak typical AC output voltage

N Adjustable output frequency controls lamp

color and power consumption

N Adjustable converter frequency minimizes

circuit power consumption

N Disable mode extends battery life

N Disable current 1µA typical

N Compact MicroSO package option

Key Features

Applications

Block Diagram

–

+

527_01.eps

1

4

3

7

6

2

Switch

Oscillator

Regulation

Control

IMP527

Bridge

Output

Driver

Q

Q

Q

Lamp Drive

Oscillator

C

GND

5

8

Q

The IMP527 is an Electroluminescent (EL) lamp driver designed for

systems that must operate down to 1 volt and below. The input supply

voltage range is 0.9V to 2.5V. Typical output lamp drive voltage is 180V.

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 driven 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 1

tor, to ground. A disable pad (active low), 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 180V peak-to-peak. This conserves power and

extends battery life.

The IMP527 is available in MicroSO and SO-8 packages and in die form.