RT3668EB
Functional Block Diagram
SVC
VRHOT_L
PWROK
PGOOD
VDDIO
VSEN
TSEN
SET1
VCC
UVLO
SVD
SVT
MUX
ADC
SVI2 Interface
Configuration Registers
Control Logic
AI_GFX
QR_TH
TONSET
OFFSET
PHOCP_TH
IMONI
EN
GND
From Control Logic
RGND
DAC
Soft-Start &
Slew Rate Control
FB
COMP
1.867m
ISEN1P
ISEN1N
VREF_PINSET
ISEN2P
ISEN2N
IMON
+
-
Loop Control
Protection Logic
VSET
ERROR
AMP
+
-
VIN
Offset
Cancellation
+
+
-
PWM
CMP
QR_TH
BOOTx
TON
GEN
PWM1
PWM2
Driver
UGATEx
PHASEx
LGATEx
IB1
0.75 x AI_GFX
+
-
RAMP
TONSET
1.867m
+
-
IB2
IMONI
+
VSEN
OV/UV
OC
Current
Balance
IB1
IB2
Driver
POR
PVCC
OCP_SPIKE
MUX_CTRL
VSEN_NB_IN
40mV
LDO_OUT
+
-
-
To Protection Logic
LDO
VCC
0.4V
LDO_VIN
CMP
+
-
OP
10mV
+
-
+
-
LDO_OUT
VSEN_NB_IN
0
POWER
_MUX
1
LDO_OUT
FBA
S5_OUT
Operation
The RT3668EB adopts G-NAVP
TM
(Green Native AVP)
which is Richtek's proprietary topology derived from
finite DC gain of EA amplifier with current mode control,
making it easy to set the droop to meet all AMD GFX
requirements of AVP (Adaptive Voltage Positioning).
The G-NAVP
TM
MUX and ADC
The MUX supports the inputs from SET1, TSEN,
IMONI and VSEN. The ADC converts these analog
signals to digital codes for reporting or performance
adjustment.
SVI2 Interface/Configuration Registers/Control
Logic
The SVI2 interface uses the SVC, SVD, and SVT pins
to communicate with GFX. The configuration registers
save the digital data from ADC output for reporting or
performance adjustment. The Control Logic controls
the ADC timing and generates the digital code of the
VID for VSEN voltage.
controller is one type of current mode
constant on-time control with DC offset cancellation.
The approach can not only improve DC offset problem
for increasing system accuracy but also provide fast
transient response. When current feedback signal
reaches COMP signal, it generates an on-time width
to achieve PWM modulation.
Copyright © 2019 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS3668EB-05
August 2019
www.richtek.com
5
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
