G5521/A 台湾致新代理商 GMT DC-DC系列液晶显示器的集成PMIC

致新G5521/A

G5521/A 台湾致新代理商 GMT DC-DC系列液晶显示器的集成PMIC
Integrated Multi-Channel DC-DC Converter for TFT-LCD Panels

Part Number	Vin (V)min.	Vin (V) max.	FSW (k Hz)	ILX (A)	VLX(V)	OPA S/R (V/us)	OPA ISC (mA)	Note	Package
G5521/A	2.5	5.5	640/ 1200	2.0	20	12	150	Async-Boost, VGH Charge-Pump, VCOM, GPM, Voltage Detector, LDO	TQFN4X4-24

General Description

The G5521 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 activematrix thin-film transistor (TFT) liquid-crystal displays (LCDs).

The boost converter provides the regulated supply volt-age for the panel source driver ICs. The converter is a high switching frequency (640kHz or 1.2MHz) current- mode regulator with an integrated 20V N-Channel 0.2Ω MOSFET that allows the use of ultra-small inductors and ceramic capacitors. It provides fast transient re-sponse to pulsed loading while achieving efficiency over 90%. The device can produce output voltage as high as 18V from an input as low as 2.8V. Soft-Start is pro-grammed by external capacitor, which sets the in-put-current ramp-rate. The low-dropout (LDO) linear regu-lator can supply up to 350mA current while input voltage is 3.3V. It uses an internal PMOS as the pass device. It is suitable for the supply voltage of the timing controller.

The GPM is controlled by frame signals from timing con-troller to modulate the Gate-On voltage, VGHM, which acts a flicker compensation circuit to reduce the coupling effect between gate lines and pixels. It also can delay the Gate-On voltage while power-on for achieving a corrected power-on sequence for gate driver ICs. Both of power-on delay time and the falling time of the Gate-On voltage are programmable by external capacitor and resistor.

The voltage detector monitors the supply voltage to issue a reset signal while the detected voltage is too low. The de-tecting level is decided by an external resistor divider and the delay time is programmable by an external capacitor.

The VCOM buffer can drive the LCD VCOM voltage that features high short-circuit current (150mA), fast slew rate (12V/μs), wide bandwidth (12MHz) and rail-to-rail in-put/output.

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 refer-ence.

Features
2.5V to 5.5V Input Supply Range
640kHz/1.2MHz Current-Mode Boost Regulator
Fast Transient Response to Pulse Load
±1% Accurate Output Voltage
Built-In 20V/2A, 0.2ΩN-Channel MOSFET
High Efficiency up to 90%
Programmable Soft-Start
Over-Current Protection
Output Under-Voltage Protection
High-Performance Operational Amplifiers
±150mA Output Short-Circuit Current
12V/μs Slew Rate
12MHz, -3dB Bandwidth
Rail-to-Rail Input and Output
Low Dropout Voltage Linear Regulator
350mA Maximum Output Current
Adjustable Output Voltage
On-Chip GPM Controller
Adjustable Falling Time and Power-On Delay
Flicker Compensator
Power-On Sequence Control
Charge pump for VGH regulation
Low Voltage Detector
Programmable Detecting Voltage and Delay Time
Thermal-Overload Protection
RoHs Compliant
TQFN4X4-24 Package