The RT8811B 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-24L 4x4 package.
The RT8811B adopts RDS(ON) current sensing technique. Current limit is accomplished through continuous inductor-current-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 RT8811B 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.
Applications
- Motherboard to High End GPU Core Power
- High End Desktop PC Memory Core Power
- Low Voltage. High Current DC/DC Converter
- Voltage Regulator Modules