RT8877C Datasheet, PDF(1/38 Page) Richtek Technology Corporation – Dual-Output PWM Controller for AMD SVI2 CPU Power Supply

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RT8877C Datasheet, PDF (1/38 Pages) Richtek Technology Corporation – Dual-Output PWM Controller for AMD SVI2 CPU Power Supply

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RT8877C

Dual-Output PWM Controller for AMD SVI2 CPU Power

Supply

General Description

The RT8877C 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 RT8877C

features CCRCOT (Constant Current Ripple Constant On-

Time) 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 RT8877C provides special purpose offset

capabilities by pin setting. The RT8877C 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

including over voltage, under voltage and negative voltage.

Features

z 4/3/2/1-Phase (VDD) + 2/1/0-Phase (VDDNB) PWM

Controller

z G-NAVPTM Topology

z Support Dynamic Load Line and Zero Load Line

z Diode Emulation Mode at Light Load Condition

z SVI2 Interface to Comply AMD Power Management

Protocol

z Build-in ADC for VOUT and IOUT Reporting

z Immediate OV, UV and NV Protections and UVLO

z Programmable Dual OCP Mechanism

z 0.5% DAC Accuracy

z Fast Transient Response

z Power Good Indicator

z Over Current Indicator

z 52-Lead WQFN Package

z RoHS Compliant and Halogen Free

Applications

z AMD SVI2 CPU

z Desktop Computer

Simplified Application Circuit

To CPU

RT8877C

OCP_L

PWM1

SVC

PWM2

PWM3

SVD

PWM4

PWMA1

SVT

PWMA2

RT9624A

MOSFET

VVDD

VVDDNB

DS8877C-00 November 2012

is a registered trademark of Richtek Technology Corporation.

www.richtek.com

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