Dual-Phase PWM Controller with PWM-VID Reference
The RT8815A 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 RT8815A adopts RDS(ON) current sensing technique. Current limit is accomplished through continuous inductorcurrent-sense, while RDS(ON) current sensing is used for accurate channel current balance. Using the method of current sampling utilizes the best advantages of each technique.
The RT8815A features external reference input and PWMVID 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 softstart, power good indicator, and enable functions.