Part number : RT9921
Functions : Integrated Multi-Channel DC-DC Converter
Package information : VQFN-24L 4×4 Type
Manufacturer : Richtek Technology
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 (unity gain OPA), and a VGH charge pump controller for active matrix thin-film transistor (TFT) liquid-crystal displays (LCDs).
The boost converter provides the regulated supply voltage for the panel source driver ICs. The converter is a high switching frequency (640kHz or 1.2MHz) current-mode regulator with an integrated 16V N-Channel 0.2Ω MOSFET that allows the use of ultra-small inductors and ceramic capacitors. It provides fast transient response to pulsed loading while achieving efficiency over 90%. The device can produce output voltage as high as 15V from an input as low as 2.5V. Soft-Start is programmed by external capacitor, which sets the input-current ramp-rate.
1. 2.5V to 5.5V Input Supply Voltage
2. 640kHz/1.2MHz Current-Mode Boost Regulator
3. Low Dropout Voltage Linear Regulator
4. On-Chip GPM Controller with Adjustable