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HIGH-EFFICIENCY, CCFL BACKLIGHT CONTROLLER WITH AN SMBus INTERFACE
SUNNYVALE, CA-March 4, 2004-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX8709, an integrated backlight controller optimized for powering cold-cathode fluorescent lamps (CCFLs) by using a resonant, full-bridge inverter architecture. To improve CCFL lifetime, the resonant operation maximizes striking capability and provides near-sinusoidal waveforms over the entire input range. The controller operates over a wide input-voltage range of 4.6V to 28V with high power-to-light efficiency. The MAX8709 integrates safety features for protection against many single-point fault conditions, including lamp-out and short-circuit faults. This device is ideal for notebook-computer displays, LCD TVs and monitors, and automotive displays.
The MAX8709 achieves a 10:1 dimming range by "chopping" the lamp current on and off using a digitally adjusted, pulse-width modulation (DPWM) method. The brightness is controlled with a 2-wire SMBus™-compatible interface. The device directly drives the full-bridge inverter's four external
N-channel power MOSFETs. An internal 5.3V linear regulator powers the MOSFET drivers, the DPWM oscillator, and most of the internal circuitry.
The MAX8709 is available in a space-saving 28-pin TQFN package and operates over the -40°C to +85°C extended temperature range. Prices start at $4.80 (1000-up, FOB USA). To speed designs, a preassembled evaluation kit is available with recommended external components.
SMBus is a trademark of Intel Corporation.
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