ZXLB1600 Datasheet, PDF (1/16 Pages) Zetex Semiconductors – LCD BIAS BOOST CONVERTER

ZXLB1600
LCD AND OLED BIAS BOOST CONVERTER - STN, CSTN SCREENS
DESCRIPTION
The ZXLB1600 inductive switching boost converter
accepts an input voltage of between 1.6V and 5.5V and
provides an adjustable output voltage of up to 28V for
LCD and OLED bias. The device contains an output
switch and a second switch to isolate the coil from the
input to provide true isolation in shutdown mode. The
output can be adjusted by means of an externally
applied dc voltage, a PWM control signal, or external
feedback resistors and can supply typically 10mA of
output current at maximum output voltage. Higher
current is available at lower output voltages.
The input voltage range accepts a number of battery
solutions, including dual dry cell and single Li-Ion cells
and PFM operation mode allows the output to be
regulated with high efficiency under light or no load
conditions. The switching frequency range permits the
use of miniature surface mount inductors.
A low battery comparator is provided to indicate when
the input voltage has fallen to within ±2% of a preset
threshold. This threshold is set internally , but can be
adjusted externally to any voltage within the supply
voltage range.
FEATURES
• Wide input voltage range: 1.6 to 5.5V
• Adjustable output voltage up to 28V, using PWM
or analog control voltage
• Internal PWM filter
• True shutdown (output isolated from input)
• Internal output switch and current sense
• Low quiescent current: (75␮A max)
• 5␮A (max) shutdown current (including low
battery comparator)
• Up to 500kHz switching frequency
• High efficiency
• Small MSOP10 package
• Low external component count
APPLICATIONS
• PDAs
• Mobile phones - OLED sub displays
• Digital cameras
• Portable internet appliances
• Palmtop computers
• GPS terminals
TYPICAL APPLICATION CIRCUIT
ISSUE 3 - SEPTEMBER 2003
1
SEMICONDUCTORS