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