2.5V to 5.5V Input Voltage Range
Current Mode Boost Regulator
▪Built-in 18V, 3A, 0.2Ω N-MOSFET
▪1.2MHz Fixed Switching Frequency
▪Fast Load Transition Response
Positive Charge Pump Regulator
Negative Charge Pump Regulator
High Voltage Switch with Gate Pulse Modulation
▪Adjustable Power On Delay Time
Operational Amplifier for VCOM Buffer
▪±200mA Short-Circuit Current
▪40V/μs Slew Rate
▪Adjustable Detecting Voltage
▪N-Channel Open-Drain Output
Soft Start and Power On Sequencing
▪Input Under-Voltage Lockout (UVLO)
▪Over-Voltage Protection (OVP)
▪Under Voltage Protection (UVP)
▪Thermal Shutdown (OTP)
VQFN24 4 x 4 x 0.9mm Package Available
General Description

The AAT1176A device provides a boost regulator, two regulated charge pumps, an operational amplifier, a high voltage switch for gate pulse modulation (GPM), and one open drain reset output, making the device ideal for powering TFT LCD panels.
The current mode boost regulator provides a fast transient response supply voltage for the source driver ICs. It provides an output voltage up to 18V from input voltages ranging from 2.5V to 5.5V. The boost regulator integrates a low RDSON (0.2Ω) N-MOSFET, and operates at a fixed switching frequency of 1.2MHz, thereby minimizing board space while providing good efficiency.   
The positive and negative charge pump regulators provide supply voltages for the TFT LCD’s gate drivers. Both output voltages can be adjusted with external resistive voltage dividers. For improving TFT LCD image quality, a gate pulse modulation circuit shapes the gate-on signal. The slope of the gate-on voltage and GPM power on delay time can be set by external resistor and capacitor.
The operational amplifier drives the LCD backplane (VCOM). This unity-gain buffer is capable of rail-to-rail input and output, ±200mA output short-circuit current, and a 40V/μs slew rate.
The RESET function is used to monitor the device supply voltage. A reset signal is issued via an open drain NMOS when the supply is below a programmable threshold. The threshold is set by external resistors and the delay time is set by an external capacitor.
The AAT1176A regulators feature soft-start to prevent output overshoots and inrushes. Built-in power on sequencing allows for system stability. This device includes various protection features such as input under-voltage lockout (UVLO) and over temperature shutdown. Regulator outputs include overload fault protection.
The AAT1176A is available in a small 4x4x0.9mm, ultra-thin, 24 pin VQFN package with a bottom side exposed thermal pad to provide optimal heat dissipation. The device is rated to operate from –40°C to +85°C ambient temperature range.


LCD Smart Panel
LCD Notebook Panel
LCD Monitor Panel
LCD TV Panel