HV895 Datasheet, PDF (1/5 Pages) Supertex, Inc – Liquid Lens Driver

HV895
Liquid Lens Driver
Features
► Drives capacitive loads up to 200pF
► Programmable drive amplitude (up to 60V_RMS)
► On-chip boost converter
► No external inductor
► I²C interface
► Low operating current (≤20mA)
► Low standby current (≤1.0µA)
► Controlled drive edge reduces EMI
► 1.0mm × 6.0mm flip-chip
Applications
► Cell phone and PDA cameras
► Bar code readers
► Web and laptop cameras
► Biometric scanners
► Ultracompact cameras
Typical Application Circuit
I²C bus
General Description
The HV895 is designed to drive liquid lenses of up to 200pF with
a 1.5kHz waveform at amplitudes up to 60V_RMS, controlled via an
I²C interface.
A single byte (AMP) written to the HV895 controls the operation of
the driver. Setting AMP = 01h to FFh controls output amplitude in
255 monotonic steps. Setting AMP = 00h causes the HV895 to go
into low power standby mode, consuming less than 1.0µA. When
active, the HV895 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 0402 size capacitors are the
only external components required for a complete lens driver
circuit. The narrow die size and only 2 small external components
allow an entire lens driver circuit to be incorporated inside a
camera module.
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 HV895 is offered in a 1.0mm × 6.0mm lead-free solder-
bumped flip-chip.
V_DD
1.7 -2.95V
V_IN
2.65 - 5.5V
C_IN
2.2μF
6.3V
VDD
SDA
SCL
VIN1
VIN2
HV895
OUT1
OUT2
HV GND1 GND2
C_HV
4.7nF
100V
Liquid Lens
100 -200pF