The RT8809A/B is a dual-phase synchronous buck PWM controller with integrated drivers which are optimized for high performance graphic microprocessor and computer applications. The IC integrates a G-NAVPTM PWM controller, two 12V MOSFET drivers with internal bootstrap diodes, as well as output current monitoring and protection functions into the WQFN-24L 4x4 package. The RT8809A/B adopts DCR and RDS(ON) current sensing. Load line voltage positioning (droop) and over current protection are accomplished through continuous inductor DCR current sensing, while RDS(ON) current sensing is used for accurate channel current balance. Using both methods of current sampling utilizes the best advantages of each technique. The RT8809A/B also features a one-bit VID control operation in which the feedback voltage is regulated and tracks external input reference voltage. Other features include, adjustable operating frequency, external compensation, and enable/shutdown functions.