RT9921 - Richtek Technology Corporation

RT9921 Integrated Multi-Channel DC-DC Converter

The RT9921 includes a high-performance boost regulator, a low dropout linear regulator (LDO), a gate pulse modulator (GPM), a voltage detector, a VCOM buffer (unitygain OPA), and a VGH charge pump controller for activematrix thin-film transistor (TFT) liquid-crystal displays (LCDs). The boost converter provides the regulated supply voltage for the panel sour.

Features

high short-circuit current (140mA), fast slew rate (12V/μs), wide bandwidth (12MHz) and rail-to-rail inputs and outputs. The VGH charge pump controller provides regulated TFT Gate-On voltage. The regulation of the positive charge pump is generated by the internal comparator that senses the output voltage and compares it with an internal reference. Features
 2.5V to 5.5V Input Supply Voltage
 640kHz/1.2MHz Current-Mode Boost Regulator  Fast Transient Response to Pulsed Load  Adjustable Output Voltage (±1%)  Built-In 16V, 2A, 0.2Ω N-MOSFET  High Efficiency Up to 90%  Programmable Soft-St.