EUP2644
TFT LCD DC-DC Converter with Integrated
LDO, OP-AMP and GPM Switch
DESCRIPTION
The EUP2644 generates power supply rails for thin-film
transistor (TFT) liquid-crystal display (LCD) panels in
monitors and notebooks operation from 3V to 5.5V input
supply. The device integrates a step-up converter, a high
speed V
COM
buffer, a 350mA low dropout (LDO) linear
regulator, and a Gate Pulse Modulator (GPM).
The external compensated step up converter features an
internal power MOSFET and high frequency operation
allowing the use of small inductors and capacitors. The step
up converter uses fixed-frequency, current mode control
architecture which provides fast load-transient response and
easy compensation. A 3.3A peak current limit for the
internal switch protects power supply fault condition.
The GPM provides a modulated voltage to the gate driver
circuitry of a TFT LCD display. It allows shaping of the
gate high voltage to improve image quality. It also can
delay the gate high voltage while power on. Both the
power-on delay time and the falling time of the gate high
voltage are programmable by external resistor and
capacitor.
The high speed V
COM
butter features continues output
current (±100mA), 20MHz bandwidth, fast slew rate
70V/µs, and rail-to-rail inputs and outputs.
The LDO regulator provides up to 350mA current to the
external digital circuitry.
FEATURES
3V to 5.5V Input Supply Range
Current Mode Step Up Converter
- Selectable Frequency (650kHz/1.2MHz)
- Built-In 20V, 3.3A, 0.15Ω N-MOSFET
- High Efficiency Up to 90%
- Programmable Soft-Start
- Fast Transient Response to Pulsed Load
Gate Pulse Modulator Circuit
- Adjustable Falling Time and Delay
- Flicker Compensation
High Speed High Output Current V
COM
Buffer
- 20MHz BW
- 70V/µS Slew Rate
- 400mA Peak Output Current
350mA LDO Regulator for V
LOGIC
- Adjustable Output Voltage：2.5V, 2.85V, 3.3V
Input Under Voltage Lockout and Thermal Protection
24 pin 4mm
×
4mm TQFN Package
RoHS Compliant and 100% Lead (Pb)-Free
APPLICATIONS
LCD Monitors
Notebook Display
DS2644
Ver1.0
Aug. 2008
1
EUTECH [ EUTECH MICROELECTRONICS INC ]
