DC/DC converter has five op amps

Maxim Integrated Products introduces the MAX8795A TFT-LCD DC-DC converter. The device saves both space and cost by integrating a 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 25mm? footprint.

Designed to drive the LCD backplane (Vcom) and/or gamma-correction divider string, the operational amplifiers feature a high ±130mA output current, fast 45V/?s slew rate, wide 20MHz bandwidth and rail-to-rail operation on the input and output. The high integration and performance of MAX8795A, combined with its low cost and small size, make it suitable for active-matrix, TFT-LCD TV and monitor display applications.

To further reduce solution size, the MAX8795A uses 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 percent. Its high frequency enables the use of ultrasmall inductors and ceramic capacitors.

MAX8795A also 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 use a high-voltage-switch control matrix to improve system operation and efficiency while powering the LCD-panel row drivers.

Available in a small, 5-by-5-by-0.8mm, 32-pin TQFN package, MAX8795A is fully specified over the -40°C to 85°C temperature range. Prices start at $3.90 for 1,000-unite quantities. An evaluation kit that includes recommended external components is available to reduce design time.