Application Information
The RT8166B is a VR12/IMVP7 compliant, dual singlephase synchronous Buck PWM controller for the CPU
CORE VR and GFX VR. The gate drivers are embedded
to facilitate PCB design and reduce the total BOM cost. A
Serial VID (SVID) interface is built-in in the RT8166B to
communicate with Intel VR12/IMVP7 compliant CPU.
The RT8166B adopts G-NAVPTM (Green Native AVP),
which is Richtek's proprietary topology derived from finite
DC gain compensator, making it an easy setting PWM
controller to meet AVP requirements. The load line can
be easily programmed by setting the DC gain of the error
amplifier. The RT8166B has fast transient response due
to the G-NAVPTM commanding variable switching
frequency
G-NAVPTM topology also represents a high efficiency
system with green power concept. With G-NAVPTM
topology, the RT8166B becomes a green power controller
with high efficiency under heavy load, light load, and very
light load conditions. The RT8166B supports mode
transition function between CCM and DEM. These different
operating states allow the overall power system to have
low power loss. By utilizing the G-NAVPTM topology, the
operating frequency of RT8166B varies with output voltage,
load and VIN to further enhance the efficiency even in CCM
The built-in high accuracy DAC converts the SVID code
ranging from 0.25V to 1.52V with 5mV per step. The
differential remote output voltage sense and high accuracy
DAC allow the system to have high output voltage accuracy.
The RT8166B supports VR12/IMVP7 compatible power
management states and VID on-the-fly function. The power
management states include DEM in PS2/PS3 and ForcedCCM in PS1/PS0. The VID on-the-fly function has three
different slew rates : Fast, Slow and Decay. The RT8166B
integrates a high accuracy ADC for platform setting
functions, such as no-load offset and over current level.
The controller supports both DCR and sense resistor
current sensing. The RT8166B provides VR ready output
signals of both CORE VR and GFX VR. It also features
complete fault protection functions including over voltage,
under voltage, negative voltage, over current and under
voltage lockout. The RT8166B is available in a WQFN40L 5x5 small foot print package.
Design Tool
To help users reduce efforts and errors caused by manual
calculations, a user-friendly design tool is now available
on request. This design tool calculates all necessary
design parameters by entering user's requirements.
Please contact Richtek's representatives for details.
Serial VID (SVID) Interface
SVID is a three-wire serial synchronous interface defined
by Intel. The three wire bus includes VDIO, VCLK and
ALERT signals. The master (Intel's VR12/IMVP7 CPU)
initiates and terminates SVID transactions and drives the
VDIO, VCLK, and ALERT during a transaction. The slave
(RT8166B) receives the SVID transactions and acts
accordingly.
