AAT11771
Features
Built-in 3A, 0.2Ω Switching NMOS
VGH and VGL Charge Pumps
VCOM Operational Amplifier
Adjustable VGH Delay
Open-Drain Reset Output for TCON
1.2MHz Fixed Switching Frequency
Thermal Protection
Low Dissipation Current: Typical 2.3mA in Operation
VQFN24 4 x 4 Package Available
General Description
The AAT11771 provides a step-up PWM controller, dual charge pumps, VCOM operational amplifier, and one open drain reset output for TFT LCD displays.
The PWM controller consists of an on-chip voltage reference, oscillator, error amplifier, current sense circuit, comparator, under-voltage lockout protection and soft-start control circuit. The thermal fault protection prevents excessive current from damaging internal circuit.
Integrated charge pump controllers regulate VGH and VGL. The power on sequence of AAT11771 is:
VGL –> AVDD –> VGH
(Please refer to the “Timing Chart” for more details.)
RST signal will keep high for 163ms and will pull low when the RSTIN falls below 1.25V after 163ms.
With the minimal external components, the AAT11771 offers a simple and economical solution for TFT LCD power management.
The PWM controller consists of an on-chip voltage reference, oscillator, error amplifier, current sense circuit, comparator, under-voltage lockout protection and soft-start control circuit. The thermal fault protection prevents excessive current from damaging internal circuit.
Integrated charge pump controllers regulate VGH and VGL. The power on sequence of AAT11771 is:
VGL –> AVDD –> VGH
(Please refer to the “Timing Chart” for more details.)
RST signal will keep high for 163ms and will pull low when the RSTIN falls below 1.25V after 163ms.
With the minimal external components, the AAT11771 offers a simple and economical solution for TFT LCD power management.
Application