ADM8830

Charge Pump Regulator for Color TFT Panel ADM8830 FEATURES 3 Output Voltages (+5.1 V, +15.3 V, –10.2 V) from One 3 V Input Supply Power Efficiency Optimized for Use with TFT in Mobile Phones Low Quiescent Current Low Shutdown Current (<1 A) Fast Transient Response Shutdown Function Power Saving during Blanking Period Option to Use External LDO APPLICATIONS Handheld Instruments TFT LCD Panels Cellular Phones FUNCTIONAL BLOCK DIAGRAM C5 2.2F VOLTAGE DOUBLER C1+ C1– VOUT CLKIN OSCILLATOR LDO VOLTAGE REGULATOR CONTROL LOGIC DOUBLE LDO IN C6 2.2F +5VOUT +5VIN C2+ C2– TIMING GENERATOR VOLTAGE TRIPLER SHDN SHUTDOWN CONTROL DISCHARGE VOLTAGE INVERTER TRIPLE C3+ C3– C2 1F C3 1F +15.3V C8 1F VCC ADM8830 C1 2.2F SCAN/BLANK LDO_ON/OFF +5.1V C7 2.2F +15VOUT C4+ C4– C4 1F GENERAL DESCRIPTION –10VOUT GND The ADM8830 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 output voltages (+5.1 V ± 2%, +15.3 V, –10.2 V) from a single 3 V input supply. These outputs are then used to provide supplies for the LCD controller (5.1 V) and the gate drives for the transistors in the panel (+15.3 V and –10.2 V). Only a few external capacitors are needed for the charge pumps. An efficient low dropout voltage regulator also ensures that the power efficiency is high and provides a low ripple 5.1 V output. This LDO can be shut down and an external LDO used to regulate the 5 ...