Tuesday, January 08, 2008

Maxim power-supply controller saves space and cost

Maxim Integrated Products introduces the MAX17014 highly integrated, multiple-output power-supply controller for TFT-LCD TVs and monitors. This device operates from an 8V to 16.5V input-voltage range, and is optimized for LCD-panel applications that use a 12V supply.

To save space, cost, and design time, this TFT-LCD solution integrates step-down and step-up regulators; positive and negative charge pumps; two operational amplifiers; and a Dual Mode(TM), logic-controlled, high-voltage switch-control block. The integration of these critical components enables the MAX17014 to generate all the supply rails needed for the TFT-LCD panels used in TVs and monitors.

To reduce further total solution size and cost, the step-up and step-down regulators feature internal power MOSFETs and high-frequency operation, thus enabling the use of small inductors and capacitors. Both switching regulators use fixed-frequency, current-mode control architectures to provide fast load-transient response and easy compensation.

Additionally, they provide soft-start functions to limit inrush current during startup, adjustable power-up timing, and 180 degree out-of-phase operation to minimize input ripple. Internal switch current limiting and output-fault shutdown protect the step-up and step-down power supplies against fault conditions.

To generate the supply rails for TFT-LCDs, the MAX17014 integrates positive and negative charge-pump regulators that provide TFT gate-driver supply voltages, as well as adjustable output voltages. An integrated switch-control block allows for the control of the positive TFT gate-driver voltage and power transfer.

This highly integrated device also includes two high-performance operational amplifiers that are designed to drive the LCD backplane (VCOM). The amplifiers feature a high, ±150mA output current; fast, 45V/microsecond slew rate; wide, 20MHz bandwidth; and rail-to-rail inputs and outputs.

Available in a small, 7mm x 7mm x 0.8mm, 48-pin TQFN package, the MAX17014 is fully specified over the -40 degrees Celsius to +85 degrees Celsius extended temperature range. Prices start at $4.50 (1000-up, FOB USA). An evaluation kit that includes recommended external components is available to reduce design time.

Dual Mode is a trademark of Maxim Integrated Products, Inc.

Source : Click here

comments: 0