5

HV853

Pin Descriptions: 10-Lead DFN (K7) / 8-Lead MSOP (MG)

K7

MG

Pin

Name

Description

Pin #

1

1

VDD

Input supply voltage pin.

2

2

REL

An external resistor to VDD will set the EL lamp frequency. The EL frequency is inversely

proportional to the R

quency of 280Hz

f

When using an external clock to set the EL lamp frequency, the REL pin should be con-

nected to ground.

3

3

EN

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

a delayed turn off.

4

4

CLKIN

Logic input pin. An external logic clock applied to this pin 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.

5

-

NC

No connect.

6

5

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

Logic low will cause the EL lamp frequency to be set by the external R

7,8

6

GND

IC ground pin.

9

7

VB

EL lamp driver output pin. The EL lamp is connected across VA and VB terminals.

10

8

VA

EL lamp driver output pin. The EL lamp is connected across VA and VB terminals.

EL Lamp Dimming Using PWM

EL lamp dimming can be achieved by applying a PWM signal to the ENABLE pin. This is done by pulse skipping the out-

put pulses. The PWM frequency should be kept below the EL frequency but above 50Hz to avoid flickering.

Figure 4: PWM Dimming Circuit

EL Lamp

V

DD

+

-

R

EL

8

7

6

5

VDD

VB

REL

GND

VA

1

2

3

4

EN

CLKIN CLKEN

HV853MG

GND

PWM

Signal