TFT, LCD, DC-DC Converter with Operational Amplifiers

The MAX8739 includes a high-performance, step-up regulator and two high-current operational amplifiers for active-matrix thin-film transistor (TFT) liquid-crystal displays(LCDs). The input supply voltage range of the MAX8739 is from 1.8V to 5.5V. The device also includes a logic-controlled, high-voltage switch with adjustable delay.

The step-up DC-DC converter provides the regulated supply voltage for the panel source driver ICs. The converter is a high-frequency (600kHz/1.2MHz) current-mode regulator with an integrated 14V n-channel MOSFET that allows the use of ultra-small inductors and ceramic capacitors. It provides fast transient response to pulsed loads while achieving efficiencies over 85%.

The two high-performance operational amplifiers are designed to drive the LCD backplane (VCOM) and/or the gamma-correction-divider string. The devices feature high output current (±150mA), fast slew rate (7.5V/µs), wide bandwidth (12MHz), and rail-to-rail inputs and outputs.

The MAX8739 is available in a 20-pin, 5mm x 5mm thin QFN package with a maximum thickness of 0.8mm for ultra-thin LCD panels.

Applications

* LCD Monitor Panels * Notebook Computer Displays