General Description
The RT8857/A is a 4/3/2/1-phase synchronous buck controller with 2 integrated MOSFET drivers for Intel VR11.1/VR10.x and AMD K8/K8_M2 CPUs power application. RT8857/A uses differential inductor DCR current sense to achieve phase current balance and active voltage positioning. Other features include adjustable operating frequency, adjustable soft start, power good indication, external error-amp compensation, over voltage protection, over current protection, VRHOT sensing and IMON for various applications. RT8857/A comes to a small footprint with WQFN-48L 7x7 package

Features
● 12V Power Supply Voltage
● 4/3/2/1-Phase Power Conversion
● 2 Embedded MOSFET Drivers
● Internal Regulated 5V Output
● VID table for INTEL VR11.1/VR10.x and AMD K8/K8_M2 CPUs
● Continuous Differential Inductor DCR Current Sense
● Adjustable Soft Start
● Adjustable Frequency
● Power Good Indication
● Adjustable Over Current Protection
● Over Voltage Protection
● VRHOT Sensing with External Thermistor
● IMON Output Current Indication
● Power State Indicator (PSI)
● Support MOSFET Power Stage Input Voltage (VIN) Down to 5V (RT8857A Only)
● Small 48-Lead WQFN Package
● RoHS Compliant and Halogen Free

Applications
● Desktop CPU Core Power
● Low Voltage, High Current DC/ DC Converter