RT8857应用电路及参数

4/3/2/1-Phase PWM Controller with Embedded Drivers for CPU Core Power Supply

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 
 
Application

• Desktop CPU Core Power
• Low Voltage, High Current DC/ DC Converter 
 
Typical Applications Circuit