The MP3399 is a step-up controller with 12-channel current sources designed for driving the WLED arrays for large size LCD panel backlighting applications. The MP3399 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 5V to 28V input supply. The MP3399 regulates the current in each LED string to the programmed value set by an external current setting resistor. The MP3399 applies 12 internal current sources for current balance. And the current matching can achieve 2.5% regulation accuracy between strings. Its low 600mV 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 MP3399 is flexible for extending LED channels with two or more MP3399s in parallel.
The EV3399EF-00A is an evaluation board for the MP3399EF, a 12 LED channels step-up converter designed for large liquid-crystal displays that employ an array of LEDs as the light source. The board builds with two MP3399EF in parallel to drive 24 strings LEDs with 60mA maximum current.
The MP3399 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 MP3399 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.