General Description
The EC9232 is an integrated power supply solution optimized for small to medium size thin-film transistor (TFT)
liquid crystal displays (LCD’s).
The boost converter operates at the frequency of 1.2MHz. The integrated N channel FET has a typical current limit of 3.0A and can support output voltages up to 20V.
The gate-on and gate-off charge pumps provide regulated TFT-LCD gate-on and gate-off supplies.
Both outputs can be adjusted by external resistive voltage-dividers.
The GPM is a flicker compensation circuit to reduce the coupling effect of gate lines; the gate-shaping timing is controlled by the timing-controller to modulate the Gate-On voltage, VGHM.
It also can delay the Gate-On voltage during power-on to achieve a correct power-on sequence for gate driver
ICs. Both the power-on delay time and the falling time of the Gate-On voltage are programmable by external
capacitor and resistor.
The integrated operational amplifier is typically used for LCD VCOM driving; the output can sink or source up to 350mA short-circuit current.
This operational amplifier features fast slew rate (40V/us), wide bandwidth (20MHz), and rail-to-rail outputs as well. A built-in voltage detector generates a reset signal when the input voltage drops below a specified level.
The reset signal is active low, and the detecting level is decided by an external resistor divider.
The EC9232 is available in a thin 24-pin 4×4 mm VQFN green package.
Features
◆ 2.5V to 5.5V input supply
◆ Current-mode boost regulator
－ 1.2MHz switching frequency
－ Integrated 20V/3.0A 160mΩ FET
－ Fast transient response to pulsed load
－ High efficiency up to 90%
－ Adjustable high-accuracy output voltage(±1%)
－ Over current protection
－ Over voltage protection
◆ VGH positive charge pump controller
◆ VGL negative charge pump controller
◆ Integrated high performance operational amplifier
－ ±350mA output short-circuit current
－ 40V/us fast slew rate
－ 20MHz Bandwidth
－ rail-to-rail output
◆ Low-voltage detection circuit
◆ GPM controller
－ Adjustable falling time
－ Adjustable delay
◆ Thermal shutdown
◆ Thin 4×4 mm 24-lead VQFN package
Applications
◆ TFT LCD for Notebooks
◆ TFT LCD for Monitors
◆ Car Navigation Display
◆ Portable equipment
