The MP3391 is a step-up controller with 8-channel current sources designed for driving the WLED arrays for large size LCD panel backlighting applications. The MP3391 uses current mode, fixed frequency architecture. The switching frequency is programmable by an external frequency setting resistor. It drives an external MOSFET to boost up the output voltage from a 9V to 35V input supply. The MP3391 regulates the current in each LED string to the programmed value set by an external current setting resistor. The MP3391 applies 8 internal current sources for current balance. And the current matching can achieve 2.5% regulation accuracy between strings. Its low regulation voltage on LED current sources reduces power loss and improves efficiency. PWM dimming is implemented with external PWM input signal or DC input signal. The dimming PWM signal can be generated internally, and the dimming frequency is programmed by an external setting capacitor.
The EV3391EF-00A is an evaluation board for the MP3391EF, a step-up converter designed for large liquid-crystal displays that employ an array of LEDs as the light source. It can drive up to 8 WLED strings in parallel with 80mA maximum current.
The MP3391 uses external power MOSFET and internal current mode, fixed frequency architecture and includes current ballast in each string terminal, which achieves 2.5% current regulation accuracy between strings. Low feedback voltage at each LED string help reduce power loss and improve efficiency.
The MP3391 is flexible for extending LED channels with two or more MP3391s in parallel.
The MP3391 has multiple features to protect the converter from fault conditions, including under-voltage lockout, current limiting, over voltage, short LED, open LED and thermal shut-down protection.