MAX8729

MAX8729 EVALUATION KIT AVAILABLE Constant-Frequency, Half-Bridge CCFL Inverter Controller General Description The MAX8729 cold-cathode-fluorescent lamp (CCFL) inverter controller is designed to drive multiple CCFLs using the half-bridge inverter consisting of two external n-channel power MOSFETs. The half-bridge topology minimizes the component count, while providing near sinusoidal drive waveforms. The MAX8729 operates in resonant mode during striking and switches over to constant-frequency operation after all the lamps are lit. This unique feature ensures reliable striking under all conditions and reduces the transformer stress. The MAX8729 provides accurate lamp-current regulation (±2.5%). The lamp current is adjustable with an external resistor. The MAX8729 changes the brightness by turning the CCFL on and off using a digital pulse-width modultion (DPWM) method, while maintaining the lamp current constant. The brightness can be adjusted with an analog voltage on the CNTL pin, ...