Step-Up Converter with Switch Control and Operational Amplifier for TFT LCD
SUNNYVALE, CA-May 26, 2005-Maxim Integrated Products (NASDAQ: MXIM) introduces the MAX8758 IC that includes a high-performance step-up regulator, a high-speed operational amplifier, and a logic-controlled, high-voltage switch-control block with programmable delay. The device is optimized for thin-film transistor (TFT) liquid crystal display (LCD) applications.
The step-up DC-DC regulator, featuring undervoltage lockout (UVLO), soft-start, and internal current limits, provides the regulated supply voltage for the panel source-driver ICs. The converter is a high-frequency (640kHz/1.2MHz) current-mode regulator with an integrated 14V n-channel power MOSFET that allows the use of ultra-small inductors and ceramic capacitors. The current-mode control architecture provides fast transient response to pulsed loads. The regulator achieves efficiencies over 90% by bootstrapping the supply rail of the internal gate driver from the step-up regulator output. The fully integrated, programmable, switch control block helps reduce flickers on the screen.
The integrated high-current operational amplifier is designed to drive the LCD backplane (VCOM). The amplifier features high output current (±150mA), fast slew rate (7.5V/microsecond), wide bandwidth (12MHz), and rail-to-rail inputs and outputs.
The MAX8758 is available in a 4mm x 4mm, 24-pin, TQFN package with a 0.8mm maximum thickness for ultra-thin LCD panels. The device operates over the -40 degrees Celsius to +85 degrees Celsius temperature range.
Prices start at $3.30 (1000-up, FOB USA). A preassembled MAX8758 evaluation kit is available with recommended external components to reduce design time.
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