MP3385

The MP3385 is a step-up controller with 4 regulated current channels designed to drive WLED arrays for middle and large-size LCD panel backlighting applications. The MP3385 uses peak current mode, PWM control architecture for system loop regulation. It drives an external MOSFET to boost up the output voltage from a 4.5V to 33V input supply. It employs an I2C digital interface and can flexibly set the operation and protection modes, including dimming mode, dimming current and dimming ratio, OCP, OVP, LED short protection threshold, and the switching frequency. For easy application use and board debugging, the MP3385 detects and automatically disables the unused LED strings during start-up to avoid charging the output to the OVP threshold. The MP3385 achieves 1.8% current matching between each string. The low regulation voltage on the LED current sources improves efficiency and reduces power loss in order to achieve a higher current output. The MP3385 supports analog, PWM, and combined analog and PWM dimming modes to meet different application requirements. Full protection features include OCP, OTP, UVP, OVP, LED short/open protection, and inductor/diode short protection. The MP3385 is available in a QNF-20 4mm x 4mm and a TSSOP20-EP package.