SP4405DS/18

SP4405 Low Voltage Electroluminescent Lamp Driver

© Copyright 2000 Sipex Corporation

1

s +2.2V to +4.5V Battery Operation

s DC-to-AC Converter Produces

160V

s Single Resistor Controlled Internal

Oscillator

s Low Current Standby Mode

s Internal Feedback Loop Maintains

a Constant Regulated EL Lamp

Voltage Output

APPLICATIONS

s Pagers

s Cellular Phones

s PDAs

Low Voltage Electroluminescent Lamp Driver

with Regulated Output Voltage

SP4405

DESCRIPTION

The SP4405 is a high voltage output DC-AC inverter specifically designed to drive

electroluminescent lamps to backlight liquid crystal displays, keypads, and backlit readouts

used in battery operated portable equipment. The SP4405 will operate from a +2.2V to +4.5V

battery source. The device features an internal feedback loop that regulates the lamp voltage

output to 160V

over the life of the battery. The device also has a low power shutdown mode which draws less

than 50nA (typical), ideal for low power portable products. One external inductor is required

to generate the high voltage AC output. One external resistor is used to set the internal

oscillator frequency. The SP4405 is ideal for portable applications such as pagers, cellular

phones, PDAs, and other portable applications using LCDs in dim or low light environments.

The SP4405 is offered in 8-pin SOIC and 8-pin

µSOIC packages.

COIL

SP4405

C1

0.1

µF

450k

Ω

L1

470

µH

3

6

8

1

7

2

ELEN

*D1

1N4148

0.1

µF

*optional device

EL2

EL1

EL Lamp

5

4

C2

1nF

ELEN

COIL

EL2

EL1

SP4405

8

7

4

3

2

1

5

6

®