HV852_09 Datasheet, PDF (1/7 Pages) Supertex, Inc – High Voltage,Low Noise,Inductorless EL Lamp Driver

HV852
High Voltage,
Low Noise,
Inductorless EL Lamp Driver
Features
► No external components required when using an
external EL clock frequency
► EL frequency can be set by an external resistor
► Low Noise
► DC to AC converter
► Drives up to 5.3nF (approx. 1.5in² lamp) load
► Output voltage regulation
► Enable function
► EL Lamp dimming
Applications
► Cellular phone keypad
► Watches
► Small handheld wireless devices
► MP3 Players
General Description
The Supertex HV852 is a high voltage, low noise, inductorless
EL (electroluminescent) lamp driver. It is designed to drive EL
lamps of up to 1.5in², with capacitive values up to 5.3nF over
an input voltage range of 2.4 to 5.0V. The HV852 converts a
low voltage DC input to a high voltage AC output across an
EL lamp. It uses a charge pump scheme to boost the input
voltage eliminating the need for an external inductor, diode,
and high voltage capacitor commonly found in conventional
topologies.
The charge pump circuit discharges its energy into an EL lamp
through a high voltage H-bridge. Once the voltage reaches
its regulated limit, it is turned off to conserve power. The EL
lamp is then discharged to ground and the H-bridge changes
state to allow the charge pump to charge the EL lamp in the
opposite direction.
Typical Application Circuit
+
V_DD
C_DD
-
V_DD = ON
GND = OFF
VDD
R_EL
REL
EN
VA
VB
GND
CLKIN CLKEN
HV852MG
EL Lamp frequency set by R_EL
EL LAMP
● 1235 Bordeaux Drive, Sunnyvale, CA 94089 ● Tel: [phone] ● www.supertex.com