2.3V to 5.5V Input Supply Voltage Range
1.2MHz Fixed Switching Frequency
Current Mode Boost Regulator
▪Built-in 14V, 2A, 0.2Ω N-MOSFET
▪Fast Load Transient Response
▪Adjustable Soft-Start
Low Dropout Linear Regulator
▪1.5V to VI Adjustable Output Voltage Range
▪350mA Minimum Output Current
▪±1.5% Accurate Output
Linear Regulator Controller for Gate-Off
High Voltage Switch with Gate Pulse Modulation
Unity-Gain Operational Amplifier
▪±200mA Short-Circuit Current
▪12V/μs Slew Rate
▪Adjustable Detecting Voltage and Delay Time
▪N-Channel Open-Drain Output
▪Input Under-Voltage Lockout (UVLO)
▪Under Voltage Protection (UVP)
▪Over Temperature Protection (OTP)
VQFN 24-4 x 4 x 0.9 Package Availabl
General Description
The AAT11671 is a highly integrated power management IC for TFT LCD panels. The device consists of a boost regulator, a low dropout linear regulator, a linear regulator controller for gate-off, a unity-gain operational amplifier, a high voltage switch with gate pulse modulation and one open drain RESET output.
The current mode boost regulator provides a fast transient response supply voltage for the source driver ICs. It provides an output voltage up to 14V from input voltages ranging from 2.3V to 5.5V. The boost regulator integrates a low RDSON (0.2Ω) N-MOSFET, and operates at a 1.2MHz fixed switching frequency, thereby minimizing board space while providing good efficiency. An externally programmed soft start minimizes inrush current and output overshoot.
The low dropout linear regulator typically supplies system logic power (T-CON). The LDO guarantees a minimum 350mA output current, and its output is set via external feedback resistors.
The linear regulator controller for gate-off generates an adjustable regulated negative output voltage (VGL) for the gate-off driver. For improving TFT LCD image quality, a gate pulse modulation (GPM) circuit shapes the gate high signal. The slope of the gate high voltage can be set by external resistor and capacitor.
The unity-gain operational amplifier (buffer) drives the LCD backplane (VCOM). This buffer is capable of rail-to-rail input and output, ±200mA output short-circuit current, and a 12V/μs slew rate.
A 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.
This device includes various protection features such as input under-voltage lockout (UVLO) and over temperature protection (OTP). Regulator outputs include under voltage protection (UVP).
The AAT11671 is available in a small VQFN 24 pin 4 x 4 x 0.9 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.
Smart Panel
Notebook Panel