Dual-Phase PWM Controller with PWM-VID Reference

The RT8812A is a 2/1 phase synchronous Buck PWM controller which is optimized for high performance graphic microprocessor and computer applications. The IC integrates a Constant-On-Time (COT) PWM controller, two MOSFET drivers with internal bootstrap diodes, as well as channel current balance and protection functions including Over Voltage Protection (OVP), Under Voltage Protection (UVP), current limit, and thermal shutdown into the WQFN-20L 3x3 package. The RT8812A adopts R_DS(ON) current sensing technique. Current limit is accomplished through continuous inductor-current-sense, while R_DS(ON) current sensing is used for accurate channel current balance. Using the method of current sampling utilizes the best advantages of each technique.

The RT8812A features external reference input and PWM-VID dynamic output voltage control, in which the feedback voltage is regulated and tracks external input reference voltage. Other features include adjustable switching frequency, dynamic phase number control, internal/external soft-start, power good indicator, and enable functions.