
Linear Technology
DESCRIPTION
The LT®1948 is a highly integrated multiple output DC/DC converter designed for use in TFT-LCD panels. The device contains two independent switching regulators: the main regulator has an adjustable output voltage with an internal 1.1A switch that can generate a boosted voltage as high as 30V while the second regulator generates 23V at up to 10mA for positive bias. A simple level-shift charge pump off the main switch node generates the negative bias voltage. An external capacitor sets the delay time from AVDD reaching final value to 23V appearing at the VON pin.
FEATURES
■ Complete Solution Under 1.2mm
■ Develops Three Outputs from a 3.3V or 5V Supply
■ Externally Programmable VON Delay
■ Fixed Frequency Low Noise Outputs
■ All Ceramic Capacitors
■ Operates at 3MHz Switching Frequency
■ Fast Transient Response
■ Few External Components Required
■ 2.6V to 6V Input Range
■ Tiny 8-Lead MSOP Package
APPLICATIONS
■ TFT-LCD Notebook Display Panels
■ TFT-LCD Desktop Monitor Display Panels
■ Digital Cameras
■ Handheld Computers