The MP3373 is a step-up controller with 8-channel external current sources designed for driving the WLED arrays for large-sized LCD panel backlighting applications. The device employs peak current mode, fixed-frequency architecture to provide robust operation with 9V to 40V input supply. The switching frequency is programmable by an external frequency setting resistor.
The MP3373 integrates a constant current control circuit to regulate each LED string current to the programmed value set by an external resistor. The current matching can achieve 1.2% regulation accuracy between strings. Its low 200mV regulation voltage on LED current sources reduces power loss and improves efficiency. To reduce inrush current and the stress of components, the MP3373 employs phase-shift PWM dimming mode, which can be disabled by pulling the PSEN pin to GND.
The device also includes UVLO, LED short/open protection, inductor/diode short protection, and thermal shutdown protection. All fault statuses are indicated by the fault flag signal.
The MP3373 is flexible for extending LED channels with two or three ICs in parallel, sharing one power stage. It is available in TSSOP-28 and SOIC-28 packages.