Maxim DC/DC converter tailored for active-matrix TFT LCDs

Maxim Integrated Products unveiled a new fully integrated, step-up DC/DC converter designed for active-matrix thin-film transistor (TFT) LCDs. The MAX1518B includes a high-performance step-up regulator, two linear-regulator controllers, and five high-current operational amplifiers. Also integrated is a logic-controlled, high-voltage switch with adjustable delay.

The five op amps drive the LCD backplane (VCOM) and/or the gamma-correction-divider string, and feature high output current (±150mA), a fast slew rate (13V/?s), wide bandwidth (12MHz), and rail-to-rail inputs and outputs.

The MAX1518B provides the regulated supply voltage for the panel source driver ICs. As a high-frequency (1.2MHz) current-mode regulator, this device integrates a 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 percent.

The two integrated, gate-on and gate-off linear-regulator controllers provide regulated TFT gate-on and gate-off supplies using external charge pumps attached to the switching node.

The MAX1518B is available in a small (5-by-5mm), low-profile (0.8mm), 32-pin thin QFN package and operates over the -40°C to 85°C temperature range. Prices start at $3.90 (1,000-up, FOB USA). A preassembled MAX1518B EV kit is available with recommended external components to reduce design time.