代理产线

RT8878B

 2014-05-28

【基本数据】

【产品特性】

• 4/3/2/1-Phase (VDD) + 2/1/0-Phase (VDDNB) PWM
Controller
• 2 Embedded MOSFET Drivers at the VDD Controller
• G-NAVP TM Topology
• Support Dynamic Load Line and Zero Load Line
• Diode Emulation Mode at Light Load Condition
• SVI2 Interface to Comply AMD Power Management
Protocol
• Build-in ADC for VOUTand IOUTReporting
• Immediate OV, UV and NV Protections and UVLO
• Programmable Dual OCP Mechanism
• 0.5% DAC Accuracy
• Fast Transient Response
• Power Good Indicator
• Over Current Indicator
• 52-Lead WQFN Package
• RoHS Compliant and Halogen Free


Dual-Output PWM Controller with 2 Integrated Drivers for AMD SVI2 CPU Power Supply


【产品应用】

• AMD SVI2 CPU
• Desktop Computer

【文字介绍】

The RT8878B is a 4 + 2 phases PWM controller. Moreover, it is compliant with AMD SVI2 Voltage Regulator Specification to support both CPU core (VDD) and Northbridge portion of the CPU (VDDNB). The RT8878B features CCRCOT (Constant Current Ripple Constant OnTime) with G-NAVP (Green-Native AVP), which is a Richtek's proprietary topology. G-NAVP makes it an easy setting controller to meet all AMD AVP (Active Voltage Positioning) VDD/VDDNB requirements. The droop is easily programmed by setting the DC gain of the error amplifier. With proper compensation, the load transient response can achieve optimized AVP performance. The controller also uses the interface to issue VOTF Complete and to send digitally encoded voltage and current values for the VDD and VDDNB domains. It can operate in single phase and diode emulation mode and reach up to 90% efficiency in different modes according to different loading conditions. The RT8878B provides special purpose offset capabilities by pin setting. The RT8878B also provides power good indication, over current indication (OCP_L)
and dual OCP mechanism for AMD SVI2 CPU core and NB. It also features complete fault protection functions cluding over voltage, under voltage and negative voltage.