LT1947 Datasheet

• Complete Solution Under 1.2mm
• Develops Three Outputs from a 3.3V or 5V Supply
• Externally Programmable V_ON Delay
• Fixed Frequency Low Noise Outputs
• All Ceramic Capacitors
• 3MHz Switching Frequency
• Fast Transient Response
• Few External Components Required
• 2.7V to 8V Input Range
• Adjustable AV_DD and V_ON Voltages
• Tiny 10-Lead MSOP and Thermally Enhanced 10-Lead MSOP Packages

• TFT-LCD Notebook Display Panels
• TFT-LCD Desktop Monitor Display Panels
• Digital Cameras
• Handheld Computers

The LT1947 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. The second regulator’s output is also adjustable up to 30V and can deliver 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 AV_DD’s final value to the rising edge at the V_ON pin. The 3MHz switching frequency allows the use of tiny low profile chip inductors and capacitors throughout, providing a low noise, low cost total solution with all components under 1.2mm in height.

The device operates from an input range of 2.7V to 8V and is available in 10-lead MSOP and thermally enhanced 10-lead MSOP packages.