SP4423DS/14

SP4423Electroluminescent Lamp Driver

© Copyright 2000 Sipex Corporation

5

Electroluminescent backlighting is ideal when

used with LCD displays, keypads, or other backlit

readouts. Its main use is to illuminate displays in

dim to dark conditions for momentary periods

of time. EL lamps typically consume less than

LEDs or incandescent bulbs making them ideal

for battery powered products. Also, EL lamps

are able to evenly light an area without creating

"hot spots" in the display.

Typical SP4423 Application Circuit

The amount of light emitted is a function of the

voltage applied to the lamp, the frequency at

which it is applied, the lamp material used and

its size. There are many variables which can be

optimized for specific applications. Sipex

supplies characterization charts to aid the

designer in selecting the optimum circuit

configuration (see page 6).

0.1

µF Low ESR

Decoupling

Capacitor

EL Lamp

NOTE:

Keep high voltage traces

and clock lines

Cap2

Cap1

EL1

HON

Coil

EL2

HON=0V=OFF

SP4423

NOTE:

Keep coil as close to the

SP4423 as possible

+

–

Typical SP4423 Test Circuit

0.1

µF Low ESR

Decoupling

Capacitor

NOTE:

Keep high voltage traces

and clock lines

Cap2

Cap1

EL1

HON

Coil

EL2

HON=0V=OFF

SP4423

NOTE:

Keep coil as close to the

SP4422A as possible

+

–

100

Ω

6nF