®
RT8877F
Dual-Output PWM Controller for AMD SVI2 CPU Power
Supply
General Description
The RT8877F is a 4 + 2 phases PWM controller, and is
compliant with AMD SVI2 Voltage Regulator Specification
to support both CPU core (VDD) and Northbridge portion
of the CPU (VDDNB). The RT8877F features CCRCOT
(Constant Current Ripple Constant On-Time) with the
G-NAVP (Green-Native AVP), which is Richtek's
proprietary topology. The G-NAVP makes it an easy setting
controller to meet all AMDAVP (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 RT8877F provides special purpose offset capabilities
by pin setting. The RT8877F also provides power good
indication, over-current indication (OCP_L) and dual OCP
mechanism for AMD SVI2 CPU core and NB. It also
features fault protection functions, including over-voltage,
under voltage and negative voltage protections.
Features
4/3/2/1-Phase (VDD) + 2/1/0-Phase (VDDNB) PWM
Controller
G-NAVPTM 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 VOUT and IOUT Reporting
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
Applications
AMD SVI2 CPU
Desktop Computer
Simplified Application Circuit
To CPU
RT8877F
OCP_L
PWM1
SVC
PWM2
PWM3
SVD
PWM4
PWMA1
SVT PWMA2
RT9624A
RT9624A
RT9624A
RT9624A
RT9624A
RT9624A
MOSFET
MOSFET
MOSFET
MOSFET
MOSFET
MOSFET
VVDD
VVDDNB
Copyright ©2018 Richtek Technology Corporation. All rights reserved.
DS8877F-00 April 2018
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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