2.5V to 5.5V Input Voltage Range
Current Mode Boost Regulator
▪Built-in 20V, 4.5A, 0.15Ω N-MOSFET
▪1.2MHz Fixed Switching Frequency
▪Fast Load Transient Response
Positive Charge Pump Regulator
Negative Charge Pump Regulator
High Voltage Switch with Gate Pulse Modulation
Build-in Soft Start and Power On Sequencing
▪Input Under-Voltage Lockout (UVLO)
▪Over Voltage Protection (OVP)
▪Under Voltage Protection (UVP)
▪Short Circuit Protection (SCP)
▪Over Temperature Protection (OTP)
WQFN20 5 x 5 x 0.75mm Package Available
General Description
AAT1215 device provides a boost regulator, two regulated charge pumps, and a high voltage switch for gate pulse modulation, 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 (0.15Ω) 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 (GPM) circuit shapes the gate-on signal. The slope of the gate-on voltage can be set by external resistor.
The AAT1215 regulators feature internal 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 OVP, UVP, and SCP.
The AAT1215 is available in a small 5x5x0.75mm, ultra-thin, 20 pin WQFN 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.