4

HV852

Load

R

EL

V

DD

I

DD

V

f

EL

3.3nF+1KΩ

1.5MΩ

2.4V

17.56mA

77V

245Hz

3.0V

17.53mA

79V

3.6V

17.44mA

79V

4.2V

17.65mA

79V

5.0V

18.35mA

79V

Typical Performance

Pin Description

Name

Description

V

DD

Input supply voltage pin.

R

EL

An external resistor to V

R

When using an external clock to set the EL lamp frequency, the R

EN

Enable input pin. Logic high will turn the device on. An external R-C circuit can be added for a delayed turn

off.

CLK

IN

Logic input pin. An external logic clock applied to this pad can be used to set the EL lamp frequency (see

Figure 3). The EL lamp frequency is the external clock frequency divided by 128. This is useful for applications

requiring the EL lamp to be synchronized to a system clock. Connect to ground when not in use.

CLK

EN

Logic input pin. Logic high will cause the EL lamp frequency to be set by the CLK

cause the EL lamp frequency to be set by the external R

Gnd

IC ground pin.

V

B

EL lamp driver output pin. The EL lamp is connected across V

V

A

EL lamp driver output pin. The EL lamp is connected across V

Functional Block Diagram

Feedback

EL

Oscillator

MOSFET

Full Bridge

EN

GND

Capacitor

Charge

Pump Circuit

High

Voltage

Level

Trans-

lators