HV892 Datasheet, PDF (1/6 Pages) Sirectifier Semiconductors – Inductorless Liquid Lens Driver

Supertex inc.
Inductorless
Liquid Lens Driver
HV892
Features
►►Drives capacitive loads up to 200pF
►►Programmable drive amplitude
(compatible with 40V_RMS to 60V_RMS lenses)
►►On-chip boost converter
►►No external inductor
►►I²C interface
►►Low operating current (≤20mA)
►►Low standby current (≤1.0µA)
►►Controlled drive edge reduces EMI
►►10-Lead 4x4mm DFN Package
Applications
►►Cell phone cameras
►►PDA and ultracompact cameras
►►Bar code readers
►►Web and laptop cameras
General Description
The HV892 liquid lens driver is controlled via an I²C interface,
is capable of driving capacitive loads of up to 200pF, and is
compatible with 40V_RMS to 60V_RMS lenses.
A single byte (AMP) written to the HV892 controls the operation
of the driver. Setting AMP = 01h to FFh controls output amplitude
in 255 monotonic steps. Setting AMP = 00h causes the HV892
to go into low power standby mode, consuming less than 1.0µA.
When active, the HV892 draws less than 20mA.
A charge pump boost converter integrated on-chip provides the
high voltage necessary for driving the lens. No external inductors
or diodes are needed. Two ceramic chip capacitors are the only
external components required for a complete lens driver circuit.
An H-bridge output stage provides AC drive to the lens, allowing
the use of a single high voltage boost converter while providing
alternating polarity to the lens. Controlled rising and falling edges
on the drive waveform reduces EMI.
The HV892 is offered in a 10-Lead 4x4mm DFN package.
Typical Application Circuit
I²C bus
V_IN
2.65 - 5.5V
C_IN
2.2μF 6.3V
V_DD
1.7 - 2.95V
VIN
HV
HV892
SDA
SCL
VDD
GND1
OUT1
GND2 ^OUT2
C_HV
4.7nF 100V
Liquid Lens
100 - 200pF
Doc.# DSFP-HV892
A042314
Supertex inc.
www.supertex.com