The MPQ3386 is a step-up converter with 6-channel current sources designed for driving the white LED arrays for large size LCD panel backlighting applications. The MPQ3386 uses current mode, fixed frequency architecture. The switching frequency can be selected at 1.25MHz or 625kHz. It generates an output voltage up to 50V from a 4.5V to 25V input supply. The MPQ3386 regulates the current in each LED string to the user programmed value set by an external current setting resistor. The MPQ3386 applies 6 internal current sources in each LED string terminal to get current balance. And the current matching achieves 3% regulation accuracy between strings. Its low 600mV regulation voltage on LED current sources reduces power loss and improves efficiency. The MPQ3386 features external PWM dimming or DC input PWM dimming, which allows the flexible control of the backlighting luminance under wide range of the ambient brightness, and also avoids the possibility of PWM dimming audible noise. The dimming PWM signal can be generated internally, and the dimming frequency is programmed by an external setting capacitor.