GENERAL DESCRIPTION

The ADM8839 is a charge pump regulator used for color thin film transistor (TFT) liquid crystal displays (LCDs). Using charge pump technology, the device can be used to generate three voltages (+5 V ± 2, +15 V, −15 V) from a single 3 V supply. These voltages are then used to provide supplies for the LCD controller (5 V) and the gate drives for the transistors in the panel (+15 V and −15 V). Only a few external capacitors are needed for the charge pumps. An efficient low dropout (LDO) voltage regulator ensures that the power efficiency is high, and provides a low ripple 5 V output. This LDO can be shut down and an external LDO can be used to regulate the 5 V doubler output and drive the input to the charge pump section that generates the +15 V and −15 V outputs, if required by the user.

FEATURES

3 voltages (+5 V, +15 V, −15 V) from a single 3 V supply

Power efficiency optimized for use with TFT in mobile

phones

Low quiescent current

Low shutdown current (<5 μA)

Shutdown function

Option to use external LDO

APPLICATIONS

Hand-held instruments

TFT LCD panels

Cellular phones