HV895

Features

Drives capacitive loads up to 200pF

Programmable drive amplitude (up to 60V

On-chip boost converter

No external inductor

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

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Typical Application Circuit

Liquid Lens Driver

General Description

The HV895 is designed to drive liquid lenses of up to 200pF with

a 1.5kHz waveform at amplitudes up to 60V

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.

VD

D

SDA

SCL

GND1

VIN1

HV

OUT1

OUT2

HV895

GND2

VIN2

4.7nF

100V

1.7 -2.95V

2.65 - 5.5V

2.2μF

6.3V

Liquid Lens

100 -200pF