IMP525

IMP525

4

Pin Descriptions

Pin Number

Name

Function

1

Positive voltage supply for the IMP525. Inductor L may be connected here or to a

separate supply.

2

3

Boost converter storage capacitor. The voltage across the EL lamp is equal to twice the

4

Connection to flyback inductance, L.

5

GND

Ground pin.

6

7

EL lamp drive. (See above)

8

Disable Pad

DIS

Available only in die form. Setting DIS HIGH disables the chip.

External Component

Description and Selection Guide

Diode

A fast reverse recovery diode, with BV > 100, such as a 1N4148.

The high voltage capacitor that stores the inductive energy transferred through the

catch diode. A 100 volt capacitor between 10nF and 100nF is recommended.

decreases along with the current drawn by the lamp. Lamp color is also determined by this

frequency. A 1M

Ω resistor between the R

frequency around 500Hz.

as the resistance increases.

A 100pF capacitor is recommended.

Inductor L

The inductor provides the voltage boost needed by means of inductive “flyback”. The internal

MOSFET switch alternately opens and closes the ground connection for the inductor at the

increased to prevent saturation. In general, smaller value inductors that can handle more current

are more desirable when larger-area EL lamps must be driven.

A small electrolytic capacitor (10

µF, 16V), normally present across the inductor supply V

External Components