New Industry Products

Maxim TFT-LCD DC-DC Converter Integrates Five Operational Amplifiers

July 01, 2007 by Jeff Shepard

Maxim Integrated Products introduced the MAX8795A TFT-LCD dc-dc converter. The device is claimed to save both space and cost by integrating a high-performance step-up regulator, two linear-regulator controllers, five high-current operational amplifiers, and a logic-controlled, high-voltage switch with adjustable delay in a small 25mm2 footprint.

Designed to drive the LCD backplane (Vcom) and/or gamma-correction divider string, the high-performance operational amplifiers feature a high ±130mA output current, a 45V/microsecond slew rate, wide 20MHz bandwidth, and rail-to-rail operation on the input and output. The MAX8795A is suitable for active-matrix, TFT-LCD TV and monitor display applications.

To further reduce solution size, the MAX8795A utilizes a 1.2MHz high-frequency current-mode regulator with an integrated 20V n-channel MOSFET. This converter provides a regulated supply voltage for panel source drivers, and it delivers fast transient response to pulsed loads while achieving efficiencies over 85%. Its high frequency enables the use of ultra-small inductors and ceramic capacitors. Additionally, the MAX8795A integrates gate-on and gate-off linear-regulator controllers that provide regulated, TFT gate-on and gate-off supplies using external charge pumps attached to the switching node. These power supplies utilize a high-voltage-switch control matrix to improve system operation and efficiency while powering the LCD-panel row drivers.

Available in a small, 5mm x 5mm x 0.8mm, 32-pin TQFN package, the MAX8795A is fully specified over the -40 to +85°C temperature range. Prices start at $3.90 (1000-up, FOB USA).