The MP3394S is a step-up controller with 4 current channels. It’s designed to drive WLED arrays for large-size LCD-panel backlighting applications. The MP3394S is flexible, and can expand the number of LED channels with 1 or 2 MP3394S in parallel operating from a single inductive power source. The MP3394S uses an architecture of current –mode and fixed operation frequency The frequency is programmable by an external frequency-setting resistor. MP3394S drives an external MOSFET to boost up the output voltage from a 5V to 28V input supply. It regulates the current in each LED string to the programmed value set by an external current- setting resistor. The MP3394S applies 4 internal current sources for current balance. 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. An external PWM input signal or DC input signal controls PWM dimming. In DC-input dimming mode, the dimming PWM signal can be generated internally and the dimming frequency is programmed by an external setting capacitor.
The EV3394S-S-00A is an evaluation board for the MP3394SGS, a step-up converter designed for liquid-crystal displays that employ an array of LEDs as the light source. It can drive up to 4 strings LEDs in parallel with 200mA/string maximum current.
The MP3394S 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 MP3394S 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.