Triple Output Power Supply for Small TFT-LCD Displays

The LTC3450 is a complete power converter solution for small thin film transistor (TFT) liquid crystal display (LCD) panels. The device operates from a single Lithium-Ion cell, 2- to 3-cell alkaline input or any voltage source between 1.5V and 4.6V.

The synchronous boost converter generates a low noise, high efficiency 5.1V, 10mA supply. Internal charge pumps are used to generate 10V, 15V, and -5V, -10V or -15V. Output sequencing is controlled internally to insure proper initialization of the LCD panel.

A master shutdown input reduces quiescent current to <2µA and quickly discharges each output for rapid turn off of the LCD panel. The LTC3450 is offered in a low profile (0.75mm), 3mm × 3mm 16-pin QFN package, minimizing the solution profile and footprint.

Applications

* Cellular Handsets with Color Display

* Handheld Instruments

* PDA

* Generates Three Voltages:

* 5.1V at 10mA

* 5V, -10V, or -15V at 500µA

* 10V or 15V at 500µA

* Better than 90% Efficiency

* Low Output Ripple: Less than 5mVP-P

* Complete 1mm Component Profile Solution

* Controlled Power-Up Sequence: AVDD/VGL/VGH

* All Outputs Disconnected and Actively Discharged in Shutdown

* Low Noise Fixed Frequency Operation

* Frequency Reduction Input for High Efficiency in Blank Mode

* Ultralow Quiescent Current: 75µA (Typ) in Scan Mode

* Available in a 3mm × 3mm 16-Pin QFN Package