AAT1272
Features
2.2V to 5.5V Input Supply Voltage Range
310kHz to 1.15MHz Adjustable Frequency
Current Mode Boost Regulator for AVDD
▪Built-in 18V, 2.5A, 0.15Ω N-MOSFET
▪Fast Load Transient Response
▪Adjustable Soft-Start
Current Mode Boost Regulator for VGH
▪Built-in 40V, 1.2A, 0.69Ω N-MOSFET
▪Temperature Compensation
High-Voltage Level-Shifter Scan Driver
▪Max. +40V for High Level
▪Min. –10V for Low Level
▪Rising / Falling time 20ns (Max) / 30ns (Max)
V500mA Peak Current / 15mA Continuous Current for Each Channel
▪Gate Pulse Modulation for 4 Channels
Low Dropout Linear Regulator
▪1.89V Fixed Output Voltage
▪300mA Minimum Output Current
Programmable Operational Amplifier for VCOM
▪I2C Interface
▪7-Bit, 128 Step Adjustable Sink Current Output
▪±200mA Short-Circuit Current
▪35V/μs Slew Rate
Protection
▪Input Under-Voltage Lockout (UVLO)
▪Over Voltage Protection (OVP)
▪Short Circuit Protection (SCP)
▪Over Temperature Protection (OTP)
WQFN 46-6.5 x 4.5 x 0.75 Package Available
General Description
The AAT1272 is a highly integrated power management IC for TFT LCD panels. The device consists of two current mode boost regulators, 8 channel level-shifters, a low dropout linear regulator, and a programmable operational amplifier for VCOM.
A current mode boost regulator provides a fast transient response supply voltage for the source driver. The source driver boost is capable of generating up to 16V, and includes an adjustable soft start via an external capacitor. The second current mode boost supplies a VGH voltage for the integrated level shifters, is capable of an output up to 40V, and includes a built-in pre-defined soft start. The VGH boost also includes temperature compensation via an external NTC thermistor. Both boost regulators integrate a low RDSON N-MOSFET, and operates at an adjustable switching frequency between 310kHz and 1.15MHz.
The high-voltage level shifter is designed to drive the TFT panels with row drivers integrated on the panel glass. Its eight output can swing from +40V to –10V and swiftly drive capacitive loads. For improving TFT LCD image quality, a gate pulse modulation (GPM) circuit shapes the gate high signal (VGH). The slope of the gate high voltage (VGH) can be set by external resistor.
The low dropout linear regulator typically supplies system logic power (T-CON). The 1.89V Fixed output voltage LDO guarantees a minimum 300mA output current. The programmable 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 35V/μs slew rate. It’s programmed by I2C interface with 7-bit, 128 step adjustable sink current output that can replace mechanical potentiometers to reduce labor cost.  
The AAT1272 device includes various protection features such as input under-voltage lockout (UVLO) and over temperature shutdown (OTP). Regulator outputs include overload voltage protection (OVP), and short circuit protection (SCP).
The AAT1272 is available in a small WQFN 46 pin 6.5X4.5X0.75 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.
 
Application
Smart Panel
Notebook Panel