HV823
HV823
High-Voltage EL Lamp Driver
Ordering Information
Package Options
Device
Input Voltage
8-Lead SO
Die
HV823
2.0V to 9.5V
HV823LG
HV823X
Features
General Description
Processed with HVCMOS® technology
The Supertex HV823 is a high-voltage driver designed for driving
EL lamps of up to 50nF. EL lamps greater than 50nF can be
driven for applications not requiring high brightness. The input
supply voltage range is from 2.0 to 9.5V. The device uses a single
inductor and a minimum number of passive components. The
nominal regulated output voltage that is applied to the EL lamp
is ±90V. The chip can be enabled by connecting the resistors on
RSW-osc and REL-osc to VDD and disabled when connected to GND.
2.0V to 9.5V operating supply voltage
DC to AC conversion
180V peak-to-peak typical output voltage
Large output load capability typically 50nF
Permits the use of high-resistance elastomeric lamp
components
The HV823 has two internal oscillators, a switching MOSFET,
and a high-voltage EL lamp driver. The frequency for the switching converter MOSFET is set by an external resistor connected
between the RSW-osc pin and the supply pin VDD. The EL lamp
driver frequency is set by an external resistor connected between REL-osc pin and the VDD pin. An external inductor is
connected between the Lx and VDD pins. A 0.01µF to 0.1µF
capacitor is connected between CS and GND. The EL lamp is
connected between VA and VB.
Adjustable output lamp frequency to control lamp color,
lamp life, and power consumption
Adjustable converter frequency to eliminate harmonics and
optimize power consumption
Enable/disable function
Low current draw under no load condition
The switching MOSFET charges the external inductor and
discharges it into the Cs capacitor. The voltage at Cs will start to
increase. Once the voltage at Cs reaches a nominal value of 90V,
the switching MOSFET is turned OFF to conserve power. The
outputs VA and VB are configured as an H-bridge and are
switched in opposite states to achieve 180V peak-to-peak across
the EL lamp.
Applications
Handheld personal computers
Electronic personal organizers
GPS units
Pagers
Cellular phones
Portable instrumentation
Pin Configuration
Absolute Maximum Ratings*
Supply Voltage, VDD
-0.5V to +10V
Output Voltage, VCs
-0.5V to +120V
Operating Temperature Range
-25°C to +85°C
Storage Temperature Range
Power Dissipation
ςΑ
R EL-osc
2
7
VA
3
6
VB
Lx
Note:
*All voltages are referenced to GND.
8
Cs
400mW
1
RSW-osc
-65°C to +150°C
VDD
4
5
GND
SO-8
15-17
