RT8167B
Dual Single-Phase PWM Controller for CPU and GPU Core
Power Supply
General Description
Features
The RT8167B is a dual single-phase PWM controller with
integrated MOSFET drivers, compliant with Intel IMVP7
Pulse Width Modulation Specification to support both
CPU core and GPU core power. This part adopts G-NAVPTM
(Green-Native AVP), which is a Richtek proprietary topology
derived from finite DC gain compensator in constant ontime control mode. G-NAVPTM makes this part an easy
setting PWM controller to meet all Intel AVP (Active
Voltage Positioning) mobile CPU/GPU requirements. The
RT8167B uses SVID interface to control an 8-bit DAC for
output voltage programming. The built-in high accuracy
DAC converts the received VID code into a voltage value
ranging from 0V to 1.52V with 5mV step voltage. The
system accuracy of the controller can reach 0.8%. The
RT8167B operates in continuous conduction mode or
diode emulation mode, according to the SVID command.
The maximum efficiency can reach up to 90% in different
operating modes according to different load conditions.
The droop function (load line) can be easily programmed
by setting the DC gain of the error amplifier. With proper
compensation, the load transient response can achieve
optimized AVP performance.
z
The output voltage transition slew rate is set via the SVID
interface. The RT8167B supports both DCR and sense
resistor current sensing. The RT8167B provides
VR_READY and thermal throttling output signals for
IMVP7 CPU and GPU core. This part also features
complete fault protection functions including over voltage,
under voltage, negative voltage, over current and thermal
shutdown.
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
Dual Single-Phase PWM Controller for CPU Core
and GPU Core Power
IMVP7 Compatible Power Management States
Serial VID Interface
G-NAVPTM Topology
AVP for CPU VR Only
0.5% DAC Accuracy
0.8% System Accuracy
Differential Remote Voltage Sensing
Built-in ADC for Platform Programming
` SETINI/SETINIA for CPU/GPU Core VR Initial
Startup Voltage
` TMPMAX to Set Platform Maximum Temperature
` ICCMAX/ICCMAXA for CPU/GPU Core VR
Maximum Current
Power Good Indicator : VR_READY/VRA_READY for
CPU/GPU Core Power
Thermal Throttling Indicator : VRHOT
Diode Emulation Mode at Light Load Condition
Fast Line/Load Transient Response
Switching Frequency up to 1MHz per Phase
OVP, UVP, NVP, OTP, UVLO, OCP
Small 40-Lead WQFN Package
RoHS Compliant and Halogen Free
Applications
z
z
z
IMVP7 Intel CPU/GPU Core Power Supply
Laptop Computers
AVP Step-Down Converter
The RT8167B is available in a WQFN-40L 5x5 small
footprint package.
DS8167B-00
October 2011
www.richtek.com
1
RT8167B
Ordering Information
Pin Configurations
(TOP VIEW)
UGATE1
PHASE1
LGATE1
PVCC
LGATEA
PHASEA
UGATEA
BOOTA
EN
TONSETA
RT8167B
Package Type
QW : WQFN-40L 5x5 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Richtek products are :
`
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
`
Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
RT8167BGQW : Product Number
RT8167B
GQW
YMDNN
www.richtek.com
2
YMDNN : Date Code
40 39 38 37 36 35 34 33 32 31
BOOT1
TONSET
ISEN1P
ISEN1N
COMP
FB
RGND
GFXPS2
VCC
SETINIA
1
30
2
29
3
28
4
27
5
26
GND
25
6
24
7
8
41
23
22
9
21
10
ISENAP
ISENAN
COMPA
FBA
RGNDA
VCLK
VDIO
ALERT
VRA_READY
VR_READY
11 12 13 14 15 16 17 18 19 20
SETINI
TMPMAX
ICCMAX
ICCMAXA
TSEN
OCSET
TSENA
OCSETA
IBIAS
VRHOT
Note :
WQFN-40L 5x5
DS8167B-00
October 2011
RT8167B
Typical Application Circuit
R1
2.2
RT8167B
VCC
5V
C1
1µF
9 VCC
VCCP
R6
R7
R8
R9
TONSET 2
BOOT1
VCLK
VDIO
ALERT
VRA_READY
VR_READY
VRHOT
130 130 150 10k 10k 75
25 VCLK
24 VDIO
23 ALERT
22 VRA_READY
21 VR_READY
20
VRHOT
VCC
R17
27k
R18
8.7k
R19
10k
R20
10k
18 OCSETA
16 OCSET
10 SETINIA
11 SETINI
OCSETA
OCSET
SETINIA
SETINI
R24
10k
R25
10k
R26
NC
PHASE1
LGATE1
PVCC
40
R4 0
1
R5
R31 R32
100k NC
38
ICCMAX
ICCMAXA
GFXPS2
R37
33k
R38
5.1k
R39
1.6k
R40
10k
NTCT1
10k
ß = 3380
R47
12k
R71
750
R72
750
R52
1k
3
ISEN1P
ISEN1N 4
6
FB
October 2011
VCORE
R14
3.9k
5V
Optional Optional
C10
NTC1
4.7k
ß = 3500
R15
4.7k
R16
2.4k
C26
330µF
/9m
C5
330µF
/9m
C6
0.068µF
C9 Optional
C11
CORE VCC SENSE
COMP
BOOTA
PHASEA
5
R21
R22
R23
7
71k
10k
100
VCORE
CORE VSS SENSE
R34
5.1
R33
130k
33 R36 0
VIN
5V to 25V
C12
0.1µF
Q3
C13
0.1µF
35
C14
10µF
DCR = 14.6m
L2
2µH
Optional
R42
Q4
R43
11k
15 TSEN
19 IBIAS
C17
330µF
/15m
C16
0.1µF
R45
1.2k
C18
Optional Optional
C19
VGFX
C27
330µF
/15m
C15
R44
1k
NTCA
1k
ß = 3650
Optional
C20
GFX VCC SENSE
17 TSENA
28
R48
R49
R50
RGNDA 26
42k
10k
100
COMPA
R54
53.6k
GND
DS8167B-00
C7
37
FBA 27
Chip Enable
R13
ISENAP 30
ISENAN 29
NTCTA
10k
ß = 3380
R53
1k
DCR = 7.6m
L1
1µH
Optional
Q2
R41 0
LGATEA 36
VCC
R46
12k
R12 0
R35 0
UGATEA 34
12 TMPMAX
13 ICCMAX
14
ICCMAXA
8 GFXPS2
TMPMAX
C4
0.1µF
0
R28
100
VCC
R30
150k
C3
10µF
Q1
39
TONSETA 31
R29
51k
VIN
5V to 25V
C8
1µF
RGND
R27
NC
R3
5.1
C2
0.1µF
UGATE1
R10 R11
R2
130k
41 (Exposed Pad)
VGFX
GFX VSS SENSE
R51
100
32 EN
www.richtek.com
3
RT8167B
Table 1. IMVP7/VR12 Compliant VID Table
VID7
VID6
VID5
VID4
VID3
VID2
VID1
VID0
H1
H0
VDAC Voltage
0
0
0
0
0
0
0
0
0
0
0.000
0
0
0
0
0
0
0
1
0
1
0.250
0
0
0
0
0
0
1
0
0
2
0.255
0
0
0
0
0
0
1
1
0
3
0.260
0
0
0
0
0
1
0
0
0
4
0.265
0
0
0
0
0
1
0
1
0
5
0.270
0
0
0
0
0
1
1
0
0
6
0.275
0
0
0
0
0
1
1
1
0
7
0.280
0
0
0
0
1
0
0
0
0
8
0.285
0
0
0
0
1
0
0
1
0
9
0.290
0
0
0
0
1
0
1
0
0
A
0.295
0
0
0
0
1
0
1
1
0
B
0.300
0
0
0
0
1
1
0
0
0
C
0.305
0
0
0
0
1
1
0
1
0
D
0.310
0
0
0
0
1
1
1
0
0
E
0.315
0
0
0
0
1
1
1
1
0
F
0.320
0
0
0
1
0
0
0
0
1
0
0.325
0
0
0
1
0
0
0
1
1
1
0.330
0
0
0
1
0
0
1
0
1
2
0.335
0
0
0
1
0
0
1
1
1
3
0.340
0
0
0
1
0
1
0
0
1
4
0.345
0
0
0
1
0
1
0
1
1
5
0.350
0
0
0
1
0
1
1
0
1
6
0.355
0
0
0
1
0
1
1
1
1
7
0.360
0
0
0
1
1
0
0
0
1
8
0.365
0
0
0
1
1
0
0
1
1
9
0.370
0
0
0
1
1
0
1
0
1
A
0.375
0
0
0
1
1
0
1
1
1
B
0.380
0
0
0
1
1
1
0
0
1
C
0.385
0
0
0
1
1
1
0
1
1
D
0.390
0
0
0
1
1
1
1
0
1
E
0.395
0
0
0
1
1
1
1
1
1
F
0.400
0
0
1
0
0
0
0
0
2
0
0.405
0
0
1
0
0
0
0
1
2
1
0.410
0
0
1
0
0
0
1
0
2
2
0.415
To be continued
www.richtek.com
4
DS8167B-00
October 2011
RT8167B
VID7
VID6
VID5
VID4
VID3
VID2
VID1
VID0
H1
H0
DAC Voltage
0
0
1
0
0
0
1
1
2
3
0.420
0
0
1
0
0
1
0
0
2
4
0.425
0
0
1
0
0
1
0
1
2
5
0.430
0
0
1
0
0
1
1
0
2
6
0.435
0
0
1
0
0
1
1
1
2
7
0.440
0
0
1
0
1
0
0
0
2
8
0.445
0
0
1
0
1
0
0
1
2
9
0.450
0
0
1
0
1
0
1
0
2
A
0.455
0
0
1
0
1
0
1
1
2
B
0.460
0
0
1
0
1
1
0
0
2
C
0.465
0
0
1
0
1
1
0
1
2
D
0.470
0
0
1
0
1
1
1
0
2
E
0.475
0
0
1
0
1
1
1
1
2
F
0.480
0
0
1
1
0
0
0
0
3
0
0.485
0
0
1
1
0
0
0
1
3
1
0.490
0
0
1
1
0
0
1
0
3
2
0.495
0
0
1
1
0
0
1
1
3
3
0.500
0
0
1
1
0
1
0
0
3
4
0.505
0
0
1
1
0
1
0
1
3
5
0.510
0
0
1
1
0
1
1
0
3
6
0.515
0
0
1
1
0
1
1
1
3
7
0.520
0
0
1
1
1
0
0
0
3
8
0.525
0
0
1
1
1
0
0
1
3
9
0.530
0
0
1
1
1
0
1
0
3
A
0.535
0
0
1
1
1
0
1
1
3
B
0.540
0
0
1
1
1
1
0
0
3
C
0.545
0
0
1
1
1
1
0
1
3
D
0.550
0
0
1
1
1
1
1
0
3
E
0.555
0
0
1
1
1
1
1
1
3
F
0.560
0
1
0
0
0
0
0
0
4
0
0.565
0
1
0
0
0
0
0
1
4
1
0.570
0
1
0
0
0
0
1
0
4
2
0.575
0
1
0
0
0
0
1
1
4
3
0.580
0
1
0
0
0
1
0
0
4
4
0.585
0
1
0
0
0
1
0
1
4
5
0.590
To be continued
DS8167B-00
October 2011
www.richtek.com
5
RT8167B
VID7
VID6
VID5
VID4
VID3
VID2
VID1
VID0
H1
H0
DAC Voltage
0
1
0
0
0
1
1
0
4
6
0.595
0
1
0
0
0
1
1
1
4
7
0.600
0
1
0
0
1
0
0
0
4
8
0.605
0
1
0
0
1
0
0
1
4
9
0.610
0
1
0
0
1
0
1
0
4
A
0.615
0
1
0
0
1
0
1
1
4
B
0.620
0
1
0
0
1
1
0
0
4
C
0.625
0
1
0
0
1
1
0
1
4
D
0.630
0
1
0
0
1
1
1
0
4
E
0.635
0
1
0
0
1
1
1
1
4
F
0.640
0
1
0
1
0
0
0
0
5
0
0.645
0
1
0
1
0
0
0
1
5
1
0.650
0
1
0
1
0
0
1
0
5
2
0.655
0
1
0
1
0
0
1
1
5
3
0.660
0
1
0
1
0
1
0
0
5
4
0.665
0
1
0
1
0
1
0
1
5
5
0.670
0
1
0
1
0
1
1
0
5
6
0.675
0
1
0
1
0
1
1
1
5
7
0.680
0
1
0
1
1
0
0
0
5
8
0.685
0
1
0
1
1
0
0
1
5
9
0.690
0
1
0
1
1
0
1
0
5
A
0.695
0
1
0
1
1
0
1
1
5
B
0.700
0
1
0
1
1
1
0
0
5
C
0.705
0
1
0
1
1
1
0
1
5
D
0.710
0
1
0
1
1
1
1
0
5
E
0.715
0
1
0
1
1
1
1
1
5
F
0.720
0
1
1
0
0
0
0
0
6
0
0.725
0
1
1
0
0
0
0
1
6
1
0.730
0
1
1
0
0
0
1
0
6
2
0.735
0
1
1
0
0
0
1
1
6
3
0.740
0
1
1
0
0
1
0
0
6
4
0.745
0
1
1
0
0
1
0
1
6
5
0.750
0
1
1
0
0
1
1
0
6
6
0.755
0
1
1
0
0
1
1
1
6
7
0.760
0
1
1
0
1
0
0
0
6
8
0.765
0
1
1
0
1
0
0
1
6
9
0.770
To be continued
www.richtek.com
6
DS8167B-00
October 2011
RT8167B
VID7
VID6
VID5
VID4
VID3
VID2
VID1
VID0
H1
H0
DAC Voltage
0
1
1
0
1
0
1
0
6
A
0.775
0
1
1
0
1
0
1
1
6
B
0.780
0
1
1
0
1
1
0
0
6
C
0.785
0
1
1
0
1
1
0
1
6
D
0.790
0
1
1
0
1
1
1
0
6
E
0.795
0
1
1
0
1
1
1
1
6
F
0.800
0
1
1
1
0
0
0
0
7
0
0.805
0
1
1
1
0
0
0
1
7
1
0.810
0
1
1
1
0
0
1
0
7
2
0.815
0
1
1
1
0
0
1
1
7
3
0.820
0
1
1
1
0
1
0
0
7
4
0.825
0
1
1
1
0
1
0
1
7
5
0.830
0
1
1
1
0
1
1
0
7
6
0.835
0
1
1
1
0
1
1
1
7
7
0.840
0
1
1
1
1
0
0
0
7
8
0.845
0
1
1
1
1
0
0
1
7
9
0.850
0
1
1
1
1
0
1
0
7
A
0.855
0
1
1
1
1
0
1
1
7
B
0.860
0
1
1
1
1
1
0
0
7
C
0.865
0
1
1
1
1
1
0
1
7
D
0.870
0
1
1
1
1
1
1
0
7
E
0.875
0
1
1
1
1
1
1
1
7
F
0.880
1
0
0
0
0
0
0
0
8
0
0.885
1
0
0
0
0
0
0
1
8
1
0.890
1
0
0
0
0
0
1
0
8
2
0.895
1
0
0
0
0
0
1
1
8
3
0.900
1
0
0
0
0
1
0
0
8
4
0.905
1
0
0
0
0
1
0
1
8
5
0.910
1
0
0
0
0
1
1
0
8
6
0.915
1
0
0
0
0
1
1
1
8
7
0.920
1
0
0
0
1
0
0
0
8
8
0.925
1
0
0
0
1
0
0
1
8
9
0.930
1
0
0
0
1
0
1
0
8
A
0.935
1
0
0
0
1
0
1
1
8
B
0.940
1
0
0
0
1
1
0
0
8
C
0.945
1
0
0
0
1
1
0
1
8
D
0.950
To be continued
DS8167B-00
October 2011
www.richtek.com
7
RT8167B
VID7
VID6
VID5
VID4
VID3
VID2
VID1
VID0
H1
H0
DAC Voltage
1
0
0
0
1
1
1
0
8
E
0.955
1
0
0
0
1
1
1
1
8
F
0.960
1
0
0
1
0
0
0
0
9
0
0.965
1
0
0
1
0
0
0
1
9
1
0.970
1
0
0
1
0
0
1
0
9
2
0.975
1
0
0
1
0
0
1
1
9
3
0.980
1
0
0
1
0
1
0
0
9
4
0.985
1
0
0
1
0
1
0
1
9
5
0.990
1
0
0
1
0
1
1
0
9
6
0.995
1
0
0
1
0
1
1
1
9
7
1.000
1
0
0
1
1
0
0
0
9
8
1.005
1
0
0
1
1
0
0
1
9
9
1.010
1
0
0
1
1
0
1
0
9
A
1.015
1
0
0
1
1
0
1
1
9
B
1.020
1
0
0
1
1
1
0
0
9
C
1.025
1
0
0
1
1
1
0
1
9
D
1.030
1
0
0
1
1
1
1
0
9
E
1.035
1
0
0
1
1
1
1
1
9
F
1.040
1
0
1
0
0
0
0
0
A
0
1.045
1
0
1
0
0
0
0
1
A
1
1.050
1
0
1
0
0
0
1
0
A
2
1.055
1
0
1
0
0
0
1
1
A
3
1.060
1
0
1
0
0
1
0
0
A
4
1.065
1
0
1
0
0
1
0
1
A
5
1.070
1
0
1
0
0
1
1
0
A
6
1.075
1
0
1
0
0
1
1
1
A
7
1.080
1
0
1
0
1
0
0
0
A
8
1.085
1
0
1
0
1
0
0
1
A
9
1.090
1
0
1
0
1
0
1
0
A
A
1.095
1
0
1
0
1
0
1
1
A
B
1.100
1
0
1
0
1
1
0
0
A
C
1.105
1
0
1
0
1
1
0
1
A
D
1.110
1
0
1
0
1
1
1
0
A
E
1.115
1
0
1
0
1
1
1
1
A
F
1.120
1
0
1
1
0
0
0
0
B
0
1.125
1
0
1
1
0
0
0
1
B
1
1.130
To be continued
www.richtek.com
8
DS8167B-00
October 2011
RT8167B
VID7
VID6
VID5
VID4
VID3
VID2
VID1
VID0
H1
H0
DAC Voltage
1
0
1
1
0
0
1
0
B
2
1.135
1
0
1
1
0
0
1
1
B
3
1.140
1
0
1
1
0
1
0
0
B
4
1.145
1
0
1
1
0
1
0
1
B
5
1.150
1
0
1
1
0
1
1
0
B
6
1.155
1
0
1
1
0
1
1
1
B
7
1.160
1
0
1
1
1
0
0
0
B
8
1.165
1
0
1
1
1
0
0
1
B
9
1.170
1
0
1
1
1
0
1
0
B
A
1.175
1
0
1
1
1
0
1
1
B
B
1.180
1
0
1
1
1
1
0
0
B
C
1.185
1
0
1
1
1
1
0
1
B
D
1.190
1
0
1
1
1
1
1
0
B
E
1.195
1
0
1
1
1
1
1
1
B
F
1.200
1
1
0
0
0
0
0
0
C
0
1.205
1
1
0
0
0
0
0
1
C
1
1.210
1
1
0
0
0
0
1
0
C
2
1.215
1
1
0
0
0
0
1
1
C
3
1.220
1
1
0
0
0
1
0
0
C
4
1.225
1
1
0
0
0
1
0
1
C
5
1.230
1
1
0
0
0
1
1
0
C
6
1.235
1
1
0
0
0
1
1
1
C
7
1.240
1
1
0
0
1
0
0
0
C
8
1.245
1
1
0
0
1
0
0
1
C
9
1.250
1
1
0
0
1
0
1
0
C
A
1.255
1
1
0
0
1
0
1
1
C
B
1.260
1
1
0
0
1
1
0
0
C
C
1.265
1
1
0
0
1
1
0
1
C
D
1.270
1
1
0
0
1
1
1
0
C
E
1.275
1
1
0
0
1
1
1
1
C
F
1.280
1
1
0
1
0
0
0
0
D
0
1.285
1
1
0
1
0
0
0
1
D
1
1.290
1
1
0
1
0
0
1
0
D
2
1.295
1
1
0
1
0
0
1
1
D
3
1.300
1
1
0
1
0
1
0
0
D
4
1.305
1
1
0
1
0
1
0
1
D
5
1.310
To be continued
DS8167B-00
October 2011
www.richtek.com
9
RT8167B
VID7
VID6
VID5
VID4
VID3
VID2
VID1
VID0
H1
H0
DAC Voltage
1
1
0
1
0
1
1
0
D
6
1.315
1
1
0
1
0
1
1
1
D
7
1.320
1
1
0
1
1
0
0
0
D
8
1.325
1
1
0
1
1
0
0
1
D
9
1.330
1
1
0
1
1
0
1
0
D
A
1.335
1
1
0
1
1
0
1
1
D
B
1.340
1
1
0
1
1
1
0
0
D
C
1.345
1
1
0
1
1
1
0
1
D
D
1.350
1
1
0
1
1
1
1
0
D
E
1.355
1
1
0
1
1
1
1
1
D
F
1.360
1
1
1
0
0
0
0
0
E
0
1.365
1
1
1
0
0
0
0
1
E
1
1.370
1
1
1
0
0
0
1
0
E
2
1.375
1
1
1
0
0
0
1
1
E
3
1.380
1
1
1
0
0
1
0
0
E
4
1.385
1
1
1
0
0
1
0
1
E
5
1.390
1
1
1
0
0
1
1
0
E
6
1.395
1
1
1
0
0
1
1
1
E
7
1.400
1
1
1
0
1
0
0
0
E
8
1.405
1
1
1
0
1
0
0
1
E
9
1.410
1
1
1
0
1
0
1
0
E
A
1.415
1
1
1
0
1
0
1
1
E
B
1.420
1
1
1
0
1
1
0
0
E
C
1.425
1
1
1
0
1
1
0
1
E
D
1.430
1
1
1
0
1
1
1
0
E
E
1.435
1
1
1
0
1
1
1
1
E
F
1.440
1
1
1
1
0
0
0
0
F
0
1.445
1
1
1
1
0
0
0
1
F
1
1.450
1
1
1
1
0
0
1
0
F
2
1.455
1
1
1
1
0
0
1
1
F
3
1.460
1
1
1
1
0
1
0
0
F
4
1.465
1
1
1
1
0
1
0
1
F
5
1.470
1
1
1
1
0
1
1
0
F
6
1.475
1
1
1
1
0
1
1
1
F
7
1.480
1
1
1
1
1
0
0
0
F
8
1.485
To be continued
www.richtek.com
10
DS8167B-00
October 2011
RT8167B
VID7
VID6
VID5
VID4
VID3
VID2
VID1
VID0
H1
H0
DAC Voltage
1
1
1
1
1
0
0
1
F
9
1.490
1
1
1
1
1
0
1
0
F
A
1.495
1
1
1
1
1
0
1
1
F
B
1.500
1
1
1
1
1
1
0
0
F
C
1.505
1
1
1
1
1
1
0
1
F
D
1.510
1
1
1
1
1
1
1
0
F
E
1.515
1
1
1
1
1
1
1
1
F
F
1.520
DS8167B-00
October 2011
www.richtek.com
11
RT8167B
Functional Pin Description
Pin No.
Pin Name
Pin Function
CPU VR Bootstrap Power Pin. This pin powers the high side MOSFET drivers.
Connect this pin to the PHASE1 pin with a bootstrap capacitor.
1
BOOT1
2
TONSET
3
ISEN1P
Single-Phase CPU VR On-Time Setting Pin. Connect this pin to VIN with a
resistor to set ripple size in PWM mode.
Positive Current Sense Input Pin of CPU VR.
4
ISEN1N
Negative Current Sense Input Pin of CPU VR.
5
COMP
CPU VR Compensation Pin. This pin is the output of the error amplifier.
6
FB
7
RGND
8
GFXPS2
9
VCC
10
11
12
13
14
15
SETINIA
SETINI
TMPMAX
ICCMAX
ICCMAXA
TSEN
16
OCSET
17
TSENA
18
OCSETA
19
IBIAS
20
VRHOT
CPU VR Feedback Pin. This pin is the inverting input node of the error amplifier.
Return Ground for CPU VR. This pin is the inverting input node for differential
remote voltage sensing.
Set Pin for GPU VR Operation Mode. Logic-high on this pin will force the GPU VR
to enter DCM.
Controller Power Supply Pin. Connect this pin to GND via a ceramic capacitor
larger than 1μF.
ADC Input for Single-Phase GPU VR VBOOT Voltage Setting.
ADC Input for Single-Phase CPU VR VBOOT Voltage Setting.
ADC Input for Single-Phase CPU VR Maximum Temperature Setting.
ADC Input for Single-Phase CPU VR Maximum Current Setting.
ADC Input for Single-Phase GPU VR Maximum Current Setting.
Thermal Monitor Sense Input Pin for CPU VR.
Set Pin for Single-Phase CPU VR Over Current Protection Threshold.
Connect a resistive voltage divider from VCC to ground, and connect the joint of
the voltage divider to the OCSET pin. The voltage, VOCSET , at this pin sets the
over current threshold, ILIMIT, for CPU VR.
Thermal Monitor Sense Input for GPU VR.
Set Pin for Single-Phase GPU VR Over Current Protection Threshold.
Connect a resistive voltage divider from VCC to ground, and connect the joint of
the voltage divider to the OCSETA pin. The voltage, VOCSETA, at this pin sets the
over current threshold, ILIMIT, for GPU VR.
Internal Bias Current Setting. Connect a 53.6kΩ resistor from this pin to GND to
set the internal bias current.
Thermal Monitor Output Pin (active low).
21
VR_READY
CPU VR Voltage Ready Indicator. This pin has an open drain output.
22
VRA_READY
GPU VR Voltage Ready Indicator. This pin has an open drain output.
23
24
25
ALERT
VDIO
VCLK
26
RGNDA
27
FBA
28
COMPA
29
30
ISENAN
ISENAP
31
TONSETA
Alert Line of SVID Interface (active low). This pin has an open drain output.
Data Transmission Line of SVID Interface.
Clock Signal Line of SVID Interface.
Return Ground for Single-Phase GPU VR.
This pin is the inverting input node for differential remote voltage sensing.
GPU VR Feedback Pin. This pin is the inverting input node of the error amplifier.
Single-Phase GPU VR Compensation Pin. This pin is the output of the error
amplifier.
Negative Current Sense Input Pin of Single-Phase GPU VR.
Positive Current Sense Input Pin of Single-Phase GPU VR.
Single-Phase GPU VR On-Time Setting Pin. Connect this pin to VIN with a
resistor to set ripple size in PWM mode.
To be continued
www.richtek.com
12
DS8167B-00
October 2011
RT8167B
Pin No.
32
33
34
35
36
37
38
39
40
41 (Exposed Pad)
DS8167B-00
Pin Name
Pin Function
EN
Voltage Regulator Enable Signal Input Pin.
GPU VR Bootstrap Power Pin. This pin powers the high side MOSFET drivers.
BOOTA
Connect this pin to the PHASEA pin with a bootstrap capacitor.
Upper Gate Driver of GPU VR. This pin drives the high side MOSFET of GPU
UGATEA
VR.
Switch Node of GPU VR. This pin is the return node of the high side MOSFET
PHASEA driver for GPU VR. Connect this pin to the joint of the source of high side
MOSFET, drain of the low side MOSFET, and the output inductor.
Lower Gate Driver of GPU VR. This pin drives the low side MOSFET of GPU
LGATEA
VR.
MOSFET Driver Power Supply Pin. Connect this pin to GND via a ceramic
PVCC
capacitor larger than 1μF.
Lower Gate Driver of CPU VR. This pin drives the low side MOSFET of CPU
LGATE1
VR.
Switch Node of CPU VR. This pin is the return node of the high side driver for
PHASE1
CPU VR. Connect this pin to the joint of the source of high side MOSFET, drain
of the low side MOSFET, and the output inductor.
Upper Gate Driver of CPU VR. This pin drives the high side MOSFET of CPU
UGATE1
VR.
Ground of Low Side MOSFET Driver. The exposed pad must be soldered to a
GND
large PCB and connected to GND for maximum power dissipation.
October 2011
www.richtek.com
13
RT8167B
VR_READY
VRA_READY
VRHOT
VCC
EN
ICCMAXA
ICCMAX
TSEN
TSENA
SETINI
SETINIA
TMPMAX
ALERT
VDIO
VCLK
Function Block Diagram
UVLO
MUX
From Control Logic
ADC
SVID XCVR
Control & Protection Logic
GFXPS2
DAC
RGNDA
Soft-Start & Slew
Rate Control
VREFA
FBA
ERROR
AMP
+
-
PWM CMP
Offset
Cancellation
TON Time
Generator
TONSETA
+
-
BOOTA
COMPA
UGATEA
Driver Logic
Control
IBIAS
From Control Logic
LGATEA
To Protection Logic
DAC
RGND
OVP/UVP/NVP
OCP
PHASEA
PVCC
10
+
ISENAP
-
ISENAN
OCSETA
Soft-Start & Slew
Rate Control
FB
VREF
ERROR
AMP
+
Offset
Cancellation
-
PWM CMP
+
TON Time
Generator
TONSET
-
COMP
BOOT1
UGATE1
To Protection Logic
ISEN1P
ISEN1N
+
10
-
OCP
Driver Logic
Control
PHASE1
LGATE1
OVP/UVP/NVP
OCSET
www.richtek.com
14
DS8167B-00
October 2011
RT8167B
Absolute Maximum Ratings
z
z
z
z
z
z
z
z
z
z
z
z
z
z
(Note 1)
PVCC, VCC to GND ------------------------------------------------------------------------------------RGNDx to GND ------------------------------------------------------------------------------------------TONSETx to GND ---------------------------------------------------------------------------------------Others ------------------------------------------------------------------------------------------------------BOOTx to PHASEx -------------------------------------------------------------------------------------PHASEx to GND
DC -----------------------------------------------------------------------------------------------------------<20ns ------------------------------------------------------------------------------------------------------UGATEx to PHASEx
DC -----------------------------------------------------------------------------------------------------------<20ns ------------------------------------------------------------------------------------------------------LGATEx to GND
DC -----------------------------------------------------------------------------------------------------------<20ns ------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
WQFN−40L 5x5 ------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
WQFN−40L 5x5, θJA ------------------------------------------------------------------------------------WQFN−40L 5x5, θJC ------------------------------------------------------------------------------------Junction Temperature -----------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------Storage Temperature Range --------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Mode) ----------------------------------------------------------------------------MM (Machine Mode) -------------------------------------------------------------------------------------
Recommended Operating Conditions
z
z
z
z
−0.3V to 6.5V
−0.3V to 0.3V
−0.3V to 28V
−0.3V to (VCC + 0.3V)
−0.3V to 6.5V
−3V to 28V
−8V to 32V
−0.3V to (BOOTx − PHASEx)
−5V to 7.5V
−0.3V to (PVCC + 0.3V)
−2.5V to 7.5V
2.778W
36°C/W
6°C/W
150°C
260°C
−65°C to 150°C
2kV
200V
(Note 4)
Supply Voltage, VCC ------------------------------------------------------------------------------------Input Voltage, VIN ----------------------------------------------------------------------------------------Junction Temperature Range --------------------------------------------------------------------------Ambient Temperature Range ---------------------------------------------------------------------------
4.5V to 5.5V
5V to 25V
−40°C to 125°C
−40°C to 85°C
Electrical Characteristics
(VCC = 5V, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
VCC /VPVCC
VEN = 1.05V, Not Switching
4.5
5
5.5
V
VIN
Battery Input Voltage
5
--
25
V
IVCC + IPVCC
VEN = 1.05V, Not Switching
--
12
20
mA
ITONSETx
VFB =1V, V IN = 12V, RTON = 100kΩ
--
110
--
μA
Supply Input
Input Voltage Range
Supply Current
(VCC + PVCC)
Supply Current
(TONSETx)
To be continued
DS8167B-00
October 2011
www.richtek.com
15
RT8167B
Parameter
Shutdown Current
(PVCC + VCC )
Symbol
Test Conditions
Min
Typ
Max
Unit
I VCC_SHDN
+ IPVCC_SHDN
VEN = 0V
--
--
5
μA
I TONSETx_SHDN
VEN = 0V
--
--
5
μA
TONSETx Voltage
VTONSETx
IRTON = 80μA, VFBx = 1V
0.95
1.075
1.2
0V
On-Time
t ON
IRTON = 80μA, VFBx = 1V
315
350
385
ns
TONSETx Input
Current Range
I RTON
VFBx = 1.1V
25
--
280
μA
Minimum Off-Time
TOFF_MIN
--
350
--
ns
4.3
--
--
V
--
--
0.7
V
VID SVID Setting = 1.000V~1.520V
OFSSVID Setting = 0V
VID SVID Setting = 0.800V~1.000V
OFSSVID Setting = 0V
−0.5
0
0.5
%VID
−5
0
5
VID SVID Setting = 0.500V~0.800V
OFSSVID Setting = 0V
−8
0
8
VID SVID Setting = 0.250V~0.500V
OFSSVID Setting = 0V
VID SVID Setting = 1.100V
OFSSVID Setting = −0.640V~0.635V
−8
0
8
−10
0
10
0
0.3125
0.5125
VINI_CORE = 0.9V, VINI_GFX = 0.9V
0.7375
0.9375
1.1375
VINI_CORE = 1V, VINI_GFX = 1V
1.3625
1.5625
1.7625
VINI_CORE = 1.1V, VINI_GFX = 1.1V
2.6125
--
5
RIBIAS = 53.6kΩ
2.09
2.14
2.19
SetVID Slow
2.5
3.125
3.75
SetVID Fast
10
12.5
15
70
80
--
dB
--
10
--
MHz
--
5
--
V/μs
0.5
--
3.6
V
--
250
--
μA
1
--
--
MΩ
Shutdown Current
(TONSETx)
TON Setting
GFX VR Forced DEM
GFXPS2x Enable
VGFXPS
Threshold
GFXPS2x Disable
VGFXPS
Threshold
References and System Output Voltage
DAC Accuracy
(PS0/PS1)
VFBx
VINI_CORE = 0V, VINI_GFX = 0V
SETINIx Voltage
VSETINIx
IBIAS Pin Voltage
VIBIAS
Dynamic VID Slew
Rate
SRDVID
mV
V
V
mV/μs
Error Amplifier
DC Gain
Gain-Bandwidth
Product
ADC
RL = 47kΩ
GBW
CLOAD = 5pF
Slew Rate
SRCOMP
CLOAD = 10pF (Gain = −4,
RLOAD_COMP = 47kΩ, VCOMPx =
0.5V to 3V)
VCOMP
RL = 47kΩ
I COMP
VCOMP = 2V
Output Voltage
Range
MAX Source/Sink
Current
Impedance of FBx
R FBx
(Note5)
(Note5)
To be continued
www.richtek.com
16
DS8167B-00
October 2011
RT8167B
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
−1
--
1
mV
Impedance of Neg. Input RISENxN
1
--
--
MΩ
Impedance of Pos. Input
1
--
--
MΩ
−50
--
100
mV
Current Sense Amplifier
Input Offset Voltage
Current Sense
Differential Input Range
Current Sense DC Gain
(Loop)
VISEN Linearity
VOFS_CSA
RISENxP
VCSDIx
VFBx = 1.1V,
VCSDIx = VISENxP − VISENxN
AI
VFBx = 1.1V, −30mV < VCSDIx < 50mV
--
10
--
V/V
VISEN_ACC
VDAC = 1.1V −30mV < VISEN_IN < 50mV
−1
--
1
%
Upper Driver Source
RUGATEx_sr
VBOOTx − VPHASEx = 5V
VBOOTx − VUGATEx = 0.1V
--
1
--
Ω
Upper Driver Sink
RUGATEx_sk
VUGATEx = 0.1V
--
1
--
Ω
Lower Driver Source
RLGATEx_sr
PVCC = 5V, PVCC − VLGATEx = 0.1V
--
1
--
Ω
Lower Driver Sink
RLGATEx_sk
VLGATEx = 0.1V
--
0.5
--
Ω
Internal Boot Charging
Switch On-Resistance
RBOOTx
PVCC to BOOTx
--
30
--
Ω
Zero Current Detection
Threshold
VZCD_TH
VZCD_TH = GND − VPHASEx
--
10
--
mV
Under Voltage Lock-out
Threshold
VUVLO
VCC Falling edge
4.04
4.24
--
V
Under Voltage Lock-out
Hysteresis
ΔVUVLO
--
100
--
mV
Over Voltage Protection
Threshold
VOVP
100
150
200
mV
Gate Driver
Protection
Respect to VOUT_MAXSVID, with 1μs
filter time
Under Voltage Protection
VUVP
Threshold
VUVP = VISENxN − VREFx, 0.8V < VREFx
−350
<1.52V, with 3μs filter time
−300
−250
mV
Negative Voltage
Protection Threshold
VNVP
VNVP = VISENxN − GND
−100
−50
--
mV
Current Sense Gain for
Over Current Protection
AOC
VOCSET = 2.4V
VISENxP − VISENxN = 50mV
--
48
--
V/V
Logic-High
VIH
With respect to 1V, 70%
0.7
--
--
Logic-Low
VIL
With respect to 1V, 30%
--
--
0.3
−1
--
1
Logic Inputs
EN Input
Threshold
Voltage
V
Leakage Current of EN
VCLK,VDIO Input
Threshold Voltage
Leakage Current of
VCLK, VDIO
VIH
With respect to Intel Spec.
0.65
--
--
VIL
With respect to Intel Spec.
--
--
0.45
−1
--
1
ILEAK_IN
μA
V
μA
To be continued
DS8167B-00
October 2011
www.richtek.com
17
RT8167B
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
--
--
0.4
V
--
--
0.4
V
70
100
160
μs
--
0.4
--
V
−1
--
1
μA
100°C
--
1.8725
--
V
97°C
--
1.8175
--
V
94°C
--
1.7625
--
V
91°C
--
1.7075
--
V
88°C
--
1.6525
--
V
85°C
--
1.5975
--
V
82°C
--
1.5425
--
V
75°C
--
1.4875
--
V
ALERT
ALERT Low Voltage
VALERT
I ALERT_ SINK = 4mA
VR Ready
VRx_READY Low Voltage VVRx_READY I VRx_READY_ SINK = 4mA
VRx_READY Delay
tVRx_READY VISENxN = VBOOT to VVRx_READY high
Thermal Throttling
VRHOT Output Voltage
VVRHOT
I VRHOT_SINK = 40mA
High Impedance Output
ALERT, VRx_READY,
VRHOT
ILEAK_OUT
Temperature Zone
TSEN Threshold for
Tmp_Zone [7] transition
TSEN Threshold for
Tmp_Zone [6] transition
TSEN Threshold for
Tmp_Zone [5] transition
VTSENx
TSEN Threshold for
Tmp_Zone [4] transition
TSEN Threshold for
Tmp_Zone [3] transition
TSEN Threshold for
Tmp_Zone [2] transition
TSEN Threshold for
Tmp_Zone [1] transition
VTSENx
TSEN Threshold for
Tmp_Zone [0] transition
Update Period
ADC
t TSEN
--
1600
--
μs
Latency
tLAT
--
--
400
μs
Digital Code of ICCMAX
Digital Code of ICCMAXA
Digital Code of TMPMAX
www.richtek.com
18
CICCMAX1
VICCMAX = 0.637V
29
32
35
decimal
CICCMAX2
VICCMAX = 1.2642V
61
64
67
decimal
CICCMAX3
VICCMAX = 2.5186V
125
128
131
decimal
CICCMAXA1
VICCMAXA = 0.1666V
5
8
11
decimal
CICCMAXA2
VICCMAXA = 0.3234V
13
16
19
decimal
CICCMAXA3
VICCMAXA = 0.637V
29
32
35
decimal
CTMPMAX1
VTMPMAX = 1.6758V
82
85
88
decimal
CTMPMAX2
VTMPMAX = 1.9698V
97
100
103
decimal
CTMPMAX3
VTMPMAX = 2.4598V
122
125
128
decimal
DS8167B-00
October 2011
RT8167B
Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for
stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.
Note 2. θJA is measured in the natural convection at TA = 25°C on a high effective thermal conductivity four-layer test board of
JEDEC 51-7 thermal measurement standard. The measurement case position of θJC is on the exposed pad of the
package.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. Guaranteed by design.
DS8167B-00
October 2011
www.richtek.com
19
RT8167B
Typical Operating Characteristics
CORE VR Power Off from EN
CORE VR Power On from EN
V CORE
(500mV/Div)
EN
(2V/Div)
VR_READY
(2V/Div)
V CORE
(500mV/Div)
EN
(2V/Div)
VR_READY
(2V/Div)
UGATE
(20V/Div)
UGATE
(20V/Div)
Boot VID = 1V
Boot VID = 1V
Time (100μs/Div)
Time (100μs/Div)
CORE VR OCP
CORE VR OVP and NVP
V CORE
(1V/Div)
V CORE
(1V/Div)
I LOAD
(10A/Div)
LGATE
(10V/Div)
VR_READY
(1V/Div)
VR_READY
(1V/Div)
UGATE
(20V/Div)
UGATE
(20V/Div)
VID = 1.1V
VID = 1.1V
Time (100μs/Div)
Time (40μs/Div)
CORE VR Dynamic VID Up
CORE VR Dynamic VID Down
V CORE
(500mV/Div)
V CORE
(500mV/Div)
VCLK
(2V/Div)
VDIO
(2V/Div)
VCLK
(2V/Div)
VDIO
(2V/Div)
ALERT
(2V/Div)
0.7V to 1.2V, Slew Rate = Slow, ILOAD = 4A
Time (40μs/Div)
www.richtek.com
20
ALERT
(2V/Div)
1.2V to 0.7V, Slew Rate = Slow, ILOAD = 4A
Time (40μs/Div)
DS8167B-00
October 2011
RT8167B
CORE VR Dynamic VID Down
CORE VR Dynamic VID Up
V CORE
(500mV/Div)
V CORE
(500mV/Div)
VCLK
(2V/Div)
VCLK
(2V/Div)
VDIO
(2V/Div)
ALERT
(2V/Div)
VDIO
(2V/Div)
ALERT
(2V/Div)
0.7V to 1.2V, Slew Rate = Fast, ILOAD = 4A
Time (10μs/Div)
Time (10μs/Div)
CORE VR Load Transient
CORE VR Load Transient
V CORE
(20mV/Div)
V CORE
(20mV/Div)
8
I LOAD
(A/Div) 1
8
I LOAD
(A/Div) 1
VID = 1.1V, ILOAD = 1A to 8A, Slew Time = 150ns
VID = 1.1V, ILOAD = 8A to 1A, Slew Time = 150ns
Time (100μs/Div)
Time (100μs/Div)
CORE VR Mode Transition
CORE VR Mode Transition
V CORE
(20mV/Div)
V CORE
(20mV/Div)
VCLK
(1V/Div)
LGATE
(10V/Div)
VCLK
(1V/Div)
LGATE
(10V/Div)
UGATE
(20V/Div)
UGATE
(20V/Div)
DS8167B-00
1.2V to 0.7V, Slew Rate = Fast, ILOAD = 4A
VID = 1.1V, PS0 to PS2, ILOAD = 0.2A
VID = 1.1V, PS2 to PS0, ILOAD = 0.2A
Time (100μs/Div)
Time (100μs/Div)
October 2011
www.richtek.com
21
RT8167B
CORE VR Thermal Monitoring
CORE VR VREF vs. Temperature
1.006
1.9
1.004
TSEN
(V/Div)
1.002
VREF (V)
1.7
1.000
0.998
0.996
0.994
VRHOT
(500mV/Div)
0.992
TSEN Sweep from 1.7V to 1.9V
0.990
Time (10ms/Div)
-50
-25
0
25
50
75
100
125
Temperature (°C)
GFX VR Power On from EN
GFX VR Power Off from EN
VGFX
(500mV/Div)
EN
(2V/Div)
VRA_READY
(2V/Div)
VGFX
(500mV/Div)
EN
(2V/Div)
VRA_READY
(2V/Div)
UGATEA
(20V/Div)
UGATEA
(20V/Div)
Boot VID = 1V
Boot VID = 1V
Time (100μs/Div)
Time (100μs/Div)
GFX VR OCP
GFX VR OVP and NVP
VGFX
(1V/Div)
VGFX
(1V/Div)
I LOAD
(5A/Div)
VRA_READY
(1V/Div)
LGATEA
(10V/Div)
VRA_READY
(1V/Div)
UGATEA
(20V/Div)
UGATEA
(20V/Div)
VID = 1.1V
Time (100μs/Div)
www.richtek.com
22
Time (40μs/Div)
DS8167B-00
October 2011
RT8167B
GFX VR Dynamic VID
GFX VR Dynamic VID
VGFX
(500mV/Div)
VGFX
(500mV/Div)
VCLK
(2V/Div)
VDIO
(2V/Div)
ALERT
(2V/Div)
VCLK
(2V/Div)
VDIO
(2V/Div)
ALERT
(2V/Div)
0.7V to 1.2V, Slew Rate = Slow, ILOAD = 1.25A
Time (40μs/Div)
Time (40μs/Div)
GFX VR Dynamic VID
GFX VR Dynamic VID
VGFX
(500mV/Div)
VGFX
(500mV/Div)
VCLK
(2V/Div)
VDIO
(2V/Div)
VCLK
(2V/Div)
VDIO
(2V/Div)
ALERT
(2V/Div)
ALERT
(2V/Div)
0.7V to 1.2V, Slew Rate = Fast, ILOAD = 1.25A
1.2V to 0.7V, Slew Rate = Fast, ILOAD = 1.25A
Time (10μs/Div)
Time (10μs/Div)
GFX VR Load Transient
GFX VR Load Transient
VGFX
(20mV/Div)
VGFX
(20mV/Div)
I LOAD 4
(A/Div) 1
I LOAD 4
(A/Div) 1
VID = 1.1V, ILOAD = 1A to 4A, Slew Time = 150ns
Time (100μs/Div)
DS8167B-00
1.2V to 0.7V, Slew Rate = Slow, ILOAD = 1.25A
October 2011
VID = 1.1V, ILOAD = 4A to 1A, Slew Time = 150ns
Time (100μs/Div)
www.richtek.com
23
RT8167B
GFX VR Mode Transition
GFX VR Mode Transition
VGFX
(20mV/Div)
VGFX
(20mV/Div)
VCLK
(1V/Div)
VCLK
(1V/Div)
LGATEA
(10V/Div)
LGATEA
(10V/Div)
UGATEA
(20V/Div)
UGATEA
(20V/Div)
VID = 1.1V, PS0 to PS2, ILOAD = 0.1A
VID = 1.1V, PS2 to PS0, ILOAD = 0.1A
Time (100μs/Div)
Time (100μs/Div)
GFX VR VREF vs. Temperature
GFX VR Thermal Monitoring
1.006
1.004
1.9
TSENA
(V/Div)
1.002
1.000
VREF (V)
1.7
0.998
0.996
0.994
0.992
VRHOT
(500mV/Div)
0.990
TSENA Sweep from 1.7V to 1.9V
Time (10ms/Div)
0.988
-50
-25
0
25
50
75
100
125
Temperature (°C)
www.richtek.com
24
DS8167B-00
October 2011
RT8167B
Application Information
The RT8167B 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 RT8167B to
communicate with Intel VR12/IMVP7 compliant CPU.
The RT8167B 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 RT8167B has fast transient response due
to the G-NAVP TM commanding variable switching
frequency.
G-NAVPTM topology also represents a high efficiency
system with green power concept. With G-NAVPTM
topology, the RT8167B becomes a green power controller
with high efficiency under heavy load, light load, and very
light load conditions. The RT8167B 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 RT8167B 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.
DS8167B-00
October 2011
The RT8167B 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 RT8167B
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 RT8167B 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 RT8167B is available in a WQFN48L 6x6 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
(RT8167B) receives the SVID transactions and acts
accordingly.
www.richtek.com
25
RT8167B
Standard Serial VID Command
Master Payload
Slave Payload
Contents
Contents
Code
Commands
00h
not supported
N/A
N/A
01h
SetVID_Fast
VID code
N/A
02h
SetVID_Slow
VID code
N/A
03h
SetVID_Decay
VID code
N/A
04h
SetPS
Byte indicating
power states
N/A
Set power state
05h
SetRegADR
Pointer of registers
in data table
N/A
Set the pointer of the data register
06h
SetReg DAT
New data register
content
N/A
Write the contents to the data register
07h
GetReg
Pointer of registers
in data table
Specified
Register
Contents
Slave returns the contents of the specified
register as the payload
08h
1Fh
not supported
N/A
N/A
N/A
www.richtek.com
26
Description
N/A
Set new target VID code, VR jumps to new VID
target with controlled default “fast” slew rate
12.5mV/μs.
Set new target VID code, VR jumps to new VID
target with controlled default “slow” slew rate
3.125mV/μs.
Set new target VID code, VR jumps to new VID
target, but does not control the slew rate. The
output voltage decays at a rate proportional to
the load current
DS8167B-00
October 2011
RT8167B
Index
00h
01h
02h
05h
Register Name
Vendor ID
Product ID
Product Revision
Protocol ID
06h
VR_Capability
10h
Status_1
11h
Status-2
Temperature
Zone
12h
15h
Output_Current
1Ch
Status_2_lastread
21h
ICC_Max
22h
Temp_Max
24h
SR-Fast
25h
SR-Slow
30h
VOUT_Max
31h
Data and Configuration Register
Description
Vendor ID, default 1Eh.
Product ID.
Product Revision.
SVID Protocol ID.
Bit mapped register, identifies the SVID VR capabilities
and which of the optional telemetry register are
supported.
Data register containing the status of VR.
Access
RO, Vendor
RO, Vendor
RO, Vendor
RO, Vendor
Default
1Eh
65h
01h
01h
RO, Vendor
81h
R-M, W-PWM
00h
Data register containing the status of transmission.
Data register showing temperature zone that have been
entered.
Data register showing direct ADC conversion of averaged
output current.
R-M, W-PWM
00h
R-M, W-PWM
00h
R-M, W-PWM
00h
The register contains a copy of the status_2.
R-M, W-PWM
00h
RO, Platform
--
RO, Platform
--
RO
0Ah
RO
02h
Data register containing the maximum ICC of platform
supports.
Binary format in Amp, IE 64h = 100A.
Data register containing the temperature max the platform
supports.
Binary format in °C, IE 64h = 100°C
Only for CORE VR
Data register containing the capability of fast slew rate the
platform can sustains. Binary format in mV/μs, IE 0Ah =
10mV/μs.
Data register containing the capability of slow slew rate.
Binary format in mV/μs IE 02h = 2.5mV/μs.
RW, Master
BFh
VID Setting
The register is programmed by the master and sets the
maximum VID.
Data register containing currently programmed VID.
RW, Master
00h
32h
Power State
Register containing the current programmed power state.
RW, Master
00h
33h
Offset
Set offset in VID steps.
RW, Master
00h
34h
Multi VR Config
Bit mapped data register which configures multiple VRs
behavior on the same bus.
RW, Master
00h
35h
Pointer
Scratch pad register for temporary storage of the
SetRegADR pointer register.
RW, Master
30h
Notes :
RO = Read Only
RW = Read/Write
R-M = Read by Master
W-PWM = Write by PWM only
Vendor = hard coded by VR vendor
Platform = programmed by platform
Master = programmed by the master
PWM = programmed by the VR control IC
DS8167B-00
October 2011
www.richtek.com
27
RT8167B
Power Ready Detection and Power On Reset (POR)
ICCMAX, ICCMAXA and TMPMAX
During start-up, the RT8167B detects the voltage on the
voltage input pins : VCC and EN. When VCC > VUVLO,
the RT8167B will recognize the power state of system to
be ready (POR = high) and wait for enable command at
EN pin. After POR = high and EN > VENTH, the RT8167B
will enter start-up sequence for both CORE VR and GFX
VR. If the voltage on any voltage pin drops below POR
threshold (POR = low), the RT8167B will enter power down
sequence and all the functions will be disabled. SVID will
be invalid within 300μs after chip becomes enabled. All
the protection latches (OVP, OCP, UVP, OTP) will be
cleared only after POR = low. EN = low will not clear
these latches.
The RT8167B provides ICCMAX, ICCMAXA and TMPMAX
pins for platform users to set the maximum level of output
current or VR temperature: ICCMAX for CORE VR
maximum current, ICCMAXA for GFX VR maximum
current, and TMPMAX for CORE VR maximum
temperature.
VCC
+
VUVLO
POR
-
EN
Chip EN
+
VENTH
-
Figure 3. Power Ready Detection and Power On Reset
(POR)
Precise Reference Current Generation
The RT8167B includes extensive analog circuits inside
the controller. These analog circuits need very precise
reference voltage/current to drive these analog devices.
The RT8167B will auto-generate a 2.14V voltage source
at IBIAS pin, and a 53.6kΩ resistor is required to be
connected between IBIAS and analog ground. Through
this connection, the RT8167B generates a 40μA current
from IBIAS pin to analog ground and this 40μA current will
be mirrored inside the RT8167B for internal use. Other
types of connection or other values of resistance applied
at the IBIAS pin may cause failure of the RT8167B's analog
circuits. Thus a 53.6kΩ resistor is the only recommended
component to be connected to the IBIAS pin. The
resistance accuracy of this resistor is recommended to
be at least 1%.
Current
Mirror
2.14V
+
-
+
-
IBIAS
53.6k
Figure 4. IBIAS Setting
www.richtek.com
28
To set ICCMAX, ICCMAXA and TMPMAX, platform
designers should use resistive voltage dividers on these
three pins. The current of the divider should be several
milli-Amps to avoid noise effect. The three items share
the same algorithms : the ADC divides 5V into 255 levels.
Therefore, LSB = 5/255 = 19.6mV, which means 19.6mV
applied to ICCMAX pin equals to 1A setting. For example,
if a platform designer wants to set TMPMAX to 120°C, the
voltage applied to TMPMAX should be 120 x 19.6mV =
2.352V. The ADC circuit inside these three pins will
decode the voltage applied and store the maximum current/
temperature setting into ICC_MAX and Temp_Max
registers. The ADC monitors and decodes the voltage at
these three pins only after EN = high. If EN = low, the
RT8167B will not take any action even when the VR output
current or temperature exceeds its maximum setting at
these ADC pins. The maximum level settings at these
ADC pins are different from over current protection or over
temperature protection. That means, these maximum level
setting pins are only for platform users to define their
system operating conditions and these messages will only
be utilized by the CPU.
V CC
ICCMAX
A/D
Converter
ICCMAXA
TMPMAX
Figure 5. ADC Pins Setting
VINI_CORE and VINI_GFX Setting
The initial start up voltage (VINI_CORE, VINI_GFX) of the
RT8167B can be set by platform users through SETINI
and SETINIA pins. Voltage divider circuit is recommended
to be applied to SETINI and SETINIA pins. The VINI_CORE/
VINI_GFX relate to SETINI/SETINIA pin voltage setting as
shown in Figure 6. Recommended voltage setting at SETINI
and SETINIA pins are also shown in Figure 6.
DS8167B-00
October 2011
RT8167B
VCC (5V)
VINI_CORE = 1.1V
VINI_GFX = 1.1V
VINI_CORE
V INI_GFX
Recommended
SETINI/SETINIA Pin Voltage
1.1V
5 x VCC≒3.125V or VCC
8
3 x VCC≒1.875V
8
3 x VCC≒0.9375V
16
1/2 VCC
VINI_CORE = 1V
VINI_GFX = 1V
VINI_CORE = 0.9V
VINI_GFX = 0.9V
VINI_CORE = 0V
VINI_GFX = 0V
1V
0.9V
1/4 VCC
1/8 VCC
0V
1 x VCC≒0.3125V or GND
16
GND
Figure 6. SETINI and SETINIA Pin Voltage Setting
Start Up Sequence
Power Down Sequence
The RT8167B utilizes internal soft-start sequence which
strictly follows Intel VR12/IMVP7 start up sequence
specifications. After POR = high and EN = high, a 300μs
delay is needed for the controller to determine whether all
the power inputs are ready for entering start up sequence.
If pin voltage of SETINI/SETINIA is zero, the output voltage
of CORE/GFX VR is programmed to stay at 0V. If pin
voltage of SETINI/SETINIA is not zero, VR output voltage
will ramp up to initial boot voltage (VINI_CORE, VINI_GFX) after
both POR = high and EN = high. After the output voltage
of CORE/GFX VR reaches target initial boot voltage, the
controller will keep the output voltage at the initial boot
voltage and wait for the next SVID commands. After the
RT8167B receives valid VID code (typically SetVID_Slow
command), the output voltage will ramp up/down to the
target voltage with specified slew rate. After the output
voltage reaches the target voltage, the RT8167B will send
out VR_READY signal to indicate the power state of the
RT8167B is ready. The VR_READY circuit is an opendrain structure so a pull-up resistor is recommended for
connecting to a voltage source.
Similar to the start up sequence, the RT8167B also utilizes
a soft shutdown mechanism during turn-off. After POR =
low, the internal reference voltage (positive terminal of
compensation EA) starts ramping down with 3.125mV/μs
slew rate, and output voltage will follow the reference
voltage to 0V. After output voltage drops below 0.2V, the
RT8167B shuts down and all functions are disabled. The
VR_READY will be pulled down immediately after POR =
low.
DS8167B-00
October 2011
www.richtek.com
29
RT8167B
VCC
POR
EN
EN Chip
(Internal Signal)
SVID
Valid
XX
xx
300µs
0.2V
VCORE
CORE VR
Operation Mode
Off
VGFX
GFX VR
Operation Mode
CCM
SVID defined
Off
CCM
0.2V
Off
CCM
SVID defined
Off
CCM
100µs
VR_READY
VRA_READY
100µs
Figure 7 (a). Power sequence for RT8167B (VINI_CORE = VINI_GFX = 0V)
VCC
POR
EN
EN Chip
(Internal Signal)
SVID
300µs
xx
Valid
XX
250µs
VINI_CORE
0.2V
VCORE
CORE VR
Operation Mode
Off
CCM
SVID defined
Off
CCM
100µs
VR_READY
50µs
VINI_GFX
VGFX
GFX VR
Operation Mode
0.2V
Off
CCM
SVID defined
Off
CCM
100µs
VRA_READY
Figure 7 (b). Power sequence for RT8167B (VINI_CORE ≠ 0, VINI_GFX ≠ 0V)
www.richtek.com
30
DS8167B-00
October 2011
RT8167B
Disable GFX VR : Before EN = High
GFX VR enable or disable is determined by the internal
circuitry that monitors the ISENAN voltage during start
up. Before EN = high, GFX VR detects whether the voltage
of ISENAN is higher than “VCC − 1V” to disable GFX
VR. The unused driver pins can be connected to GND or
left floating.
GFX VR Forced-DEM Function Enable : After
VRA_Ready = High
The GFX VR's forced-DEM function can be enabled or
disabled with GFXPS2 pin. The RT8167B detects the
voltage of GFXPS2 for forced-DEM function. If the voltage
at GFXPS2 pin is higher than 4.3V, the GFX VR operates
in forced-DEM. If this voltage is lower than 0.7V, the GFX
VR follows SVID power state command.
Loop Control
Both CORE and GFX VR adopt Richtek's proprietary GNAVPTM topology. G-NAVPTM is based on the finite-gain
valley current mode with CCRCOT (Constant Current
Ripple Constant On Time) topology. The output voltage,
VCORE or VGFX, will decrease with increasing output load
current. The control loop consists of PWM modulator with
power stage, current sense amplifier and error amplifier
as shown in Figure 8.
Similar to the valley current mode control with finite
compensator gain, the high side MOSFET on-time is
determined by the CCRCOT PWM generator. When load
current increases, VCS increases, the steady state COMP
voltage also increases which makes the output voltage
decrease, thus achieving AVP.
Droop Setting (with Temperature Compensation)
It's very easy to achieve the Active Voltage Positioning
(AVP) by properly setting the error amplifier gain due to
the native droop characteristics. The target is to have
VOUT = VREFx − ILOAD x RDROOP
(1)
Then solving the switching condition VCOMPx = VCSx in
Figure 8 yields the desired error amplifier gain as
A × RSENSE
(2)
A V = R2 = I
R1
RDROOP
where AI is the internal current sense amplifier gain and
RSENSE is the current sense resistance. If no external sense
resistor is present, the DCR of the inductor will act as
RSENSE. RDROOP is the resistive slope value of the converter
output and is the desired static output impedance.
V OUT
A V2 > A V1
A V2
VIN
High Side
MOSFET
UGATEx
GFX/CORE VR
CCRCOT
PWM Generator
Driver
Logic
Control
A V1
L
PHASEx
VOUT
(VCORE/VGFX)
RC
Low Side
MOSFET RX
CX
+
-
+
-
ISENxP
ISENxN
CByp
C2
C1
COMPx
R2
R1
CORE/GFX VR
VCC_SENSE
EA
+
+
-
FBx
RGNDx
Accuracy
C
CMP
Ai
Load Current
Figure 9. Error Amplifier Gain (AV) Influence on VOUT
LGATEx
VCSx
0
Since the DCR of inductor is temperature dependent, it
affects the output accuracy in high temperature conditions.
Temperature compensation is recommended for the
lossless inductor DCR current sense method. Figure 10
shows a simple but effective way of compensating the
temperature variations of the sense resistor using an NTC
thermistor placed in the feedback path.
C2
CORE/GFX VR
VSS_SENSE
VREFx
EA
+
R2
R1b
FBx
+
Figure 8. Simplified Schematic for Droop and Remote
Sense in CCM
COMPx
C1
RGNDx
R1a
VCC_SENSE
NTC
VSS_SENSE
VREFx
Figure 10. Loop Setting with Temperature Compensation
DS8167B-00
October 2011
www.richtek.com
31
RT8167B
Usually, R1a is set to equal RNTC (25°C), while R1b is
selected to linearize the NTC's temperature characteristic.
For a given NTC, the design would be to obtain R1b and
R2 and then C1 and C2. According to (2), to compensate
the temperature variations of the sense resistor, the error
amplifier gain (AV) should have the same temperature
coefficient with RSENSE. Hence
A V, HOT
RSENSE, HOT
=
A V, COLD RSENSE, COLD
(3)
From (2), we can have Av at any temperature (T) as
A V, T =
R2
R1a / /RNTC, T + R1b
(4)
The standard formula for the resistance of NTC thermistor
as a function of temperature is given by :
RNTC, T = RNTC, 25
{(
e
) ( )}
1
β⎡
− 1 ⎤
⎢⎣ T+273
298 ⎥⎦
(5)
where RNTC, 25 is the thermistor's nominal resistance at
room temperature, β (beta) is the thermistor's material
constant in Kelvins, and T is the thermistor's actual
temperature in Celsius.
The DCR value at different temperatures can be calculated
using the equation below :
DCRT = DCR25 x [1+0.00393 x (T-25)]
(6)
where 0.00393 is the temperature coefficient of copper.
For a given NTC thermistor, solving (4) at room temperature
(25°C) yields
R2 = AV,
25
x (R1b + R1a // RNTC, 25)
(7)
where AV, 25°C is the error amplifier gain at room temperature
obtained from (2). R1b can be obtained by substituting
(7) to (3),
R1b =
RSENSE, HOT
× (R1a // RNTC, HOT ) − (R1a // RNTC, COLD )
RSENSE, COLD
RSENSE, HOT ⎞
⎛
⎜1 − R
⎟
SENSE, COLD ⎠
⎝
(8)
Loop Compensation
Optimized compensation of the CORE VR allows for best
possible load step response of the regulator's output. A
type-I compensator with one pole and one zero is adequate
for a proper compensation. Figure 10 shows the
compensation circuit. It was previously mentioned that to
determine the resistive feedback components of error
amplifier gain, C1 and C2 must be calculated for the
compensation. The target is to achieve constant resistive
output impedance over the widest possible frequency
range.
The pole frequency of the compensator must be set to
compensate the output capacitor ESR zero :
fP =
1
2 × π × C × RC
(9)
where C is the capacitance of the output capacitor and RC
is the ESR of the output capacitor. C2 can be calculated
as follows :
C × RC
(10)
C2 =
R2
The zero of compensator has to be placed at half of the
switching frequency to filter the switching-related noise.
Such that,
1
C1 =
(11)
+
R1b
R1a
//
R
(
)× π× f
NTC, 25°C
SW
TON Setting
High frequency operation optimizes the application by
trading off efficiency due to higher switching losses with
smaller component size. This may be acceptable in ultraportable devices where the load currents are lower and
the controller is powered from a lower voltage supply. Low
frequency operation offers the best overall efficiency at
the expense of component size and board space. Figure
11 shows the on-time setting circuit. Connect a resistor
(RTONSETx) between VIN and TONSETx to set the on-time
of UGATEx :
tONx (VREFx < 1.2V) =
-12
28 × 10 × RTONSETx
VIN − VREFx
(12)
where tONx is the UGATEx turn on period, VIN is the input
voltage of converter, and VREFx is the internal reference
voltage.
www.richtek.com
32
DS8167B-00
October 2011
RT8167B
When VREFx is larger than 1.2V, the equivalent switching
frequency may be over the maximum design range, making
it unacceptable. Therefore, the VR implements a pseudoconstant-frequency technology to avoid this disadvantage
of CCRCOT topology. When VREFx is larger than 1.2V,
the on-time equation will be modified to :
tONx (VREFx ≥ 1.2V)
=
23.33 × 10
-12
× RTONSETx × VREFx
VIN − VREFx
(13)
On-time translates roughly to switching frequencies. The
on-times guaranteed in the Electrical Characteristics are
influenced by switching delays in external high side
MOSFET. Also, the dead-time effect increases the effective
on-time, reducing the switching frequency. It occurs only
in CCM during dynamic output voltage transitions when
the inductor current reverses at light or negative load
currents. With reversed inductor current, PHASEx goes
high earlier than normal, extending the on-time by a period
equal to the high side MOSFET rising dead time.
For better efficiency of the given load range, the maximum
switching frequency is suggested to be :
fS(MAX) (kHz) =
Differential Remote Sense Setting
The CORE/GFX VR includes differential, remote-sense
inputs to eliminate the effects of voltage drops along the
PC board traces, CPU internal power routes and socket
contacts. The CPU contains on-die sense pins CORE/
GFX VCC_SENSE and VSS_SENSE. Connect RGNDx to CORE/
GFX VSS_SENSE. Connect FBx to CORE/GFX VCC_SENSE
with a resistor to build the negative input path of the error
amplifier. The precision voltage reference VREFx is referred
to RGND for accurate remote sensing.
Current Sense Setting
The current sense topology of the CORE/GFX VR is
continuous inductor current sensing. Therefore, the
controller can be less noise sensitive. Low offset amplifiers
are used for loop control and over current detection. The
internal current sense amplifier gain (AI) is fixed to be 10.
The ISENxP and ISENxN denote the positive and negative
input of the current sense amplifier.
Users can either use a current sense resistor or the
inductor's DCR for current sensing. Using inductor's DCR
allows higher efficiency as shown in Figure 12. To let
1
×
tON − tHS−Delay
(15)
L = R ×C
X
X
DCR
VREFx(MAX) + ILOAD(MAX) × ⎡⎣RON _ LS−FET + DCR − RDROOP ⎤⎦ then the transient performance will be optimum. For
example, choose L = 0.36μH with 1mΩ DCR and
VIN(MAX) + ILOAD(MAX) × ⎡⎣RON _ LS−FET − RON _ HS−FET ⎤⎦
CX = 100nF, to yields for RX :
(14)
0.36μH
RX =
= 3.6kΩ
(16)
1mΩ × 100nF
where fS(MAX) is the maximum switching frequency, tHSVOUT
(VCORE/VGFX)
Delay is the turn on delay of high side MOSFET, VREFx(MAX)
is the maximum application DAC voltage of application,
V IN(MAX) is the maximum application input voltage,
ILOAD(MAX) is the maximum load of application, RON_LS-FET
is the low side MOSFET RDS(ON), RON_HS-FET is the high
side MOSFET RDS(ON), DCRL is the inductor DCR, and
RDROOP is the load line setting.
GFX/CORE
VR CCRCOT
PWM
Generator
TONSETx RTONSETx
VREFx
PHASEx
L
RX
VCSx
AI
+
-
DCR
CX
ISENxP
ISENxN
CByp
Figure 12. Lossless Inductor Sensing
R1
VIN
C1
On-Time
Figure 11. On-Time Setting with RC Filter
DS8167B-00
October 2011
www.richtek.com
33
RT8167B
Considering the inductance tolerance, the resistor RX has
to be tuned on board by examining the transient voltage.
If the output voltage transient has an initial dip below the
minimum load line requirement with a slow recovery, RX
is too small. Vice versa, if the resistance is too large the
output voltage transient will only have a small initial dip
and the recovery will be too fast, causing a ring-back.
Using current-sense resistor in series with the inductor
can have better accuracy, but the efficiency is a trade-off.
Considering the equivalent inductance (LESL) of the current
sense resistor, a RC filter is recommended. The RC filter
calculation method is similar to the above-mentioned
inductor DCR sensing method.
Operation Mode Transition
The RT8167B supports operation mode transition function
in CORE/GFX VR for the SetPS command of Intel's VR12/
IMVP7 CPU. The default operation mode of the RT8167B's
CORE/GFX VR is PS0, which is CCM operation. The other
operation mode is PS2 (DEM operation).
After receiving SetPS command, the CORE/GFX VR will
immediately change to the new operation state. When
VR receives SetPS command of PS2 operation mode,
the VR operates as a DEM controller.
If VR receives dynamic VID change command (SetVID),
VR will automatically enter PS0 operation mode. After
output voltage reaches target voltage, VR will stay at PS0
state and ignore former SetPS command. Only by
re-sending SetPS command after SetVID command will
VR be forced into PS2 operation state again.
Thermal Monitoring and Temperature Reporting
CORE/GFX VR provides thermal monitoring function via
sensing TSEN pin voltage. Through the voltage divider
resistors R1, R2, R3 and RNTC, the voltage of TSEN will
be proportional to VR temperature. When VR temperature
rises, the TSENx voltage also rises. The ADC circuit of
VR monitors the voltage variation at TSENx pin from 1.47V
to 1.89V with 55mV resolution, and this voltage is decoded
into digital format and stored into the Temperature Zone
register.
www.richtek.com
34
VCC
R1
RNTC
R2
TSENx
R3
Figure 13. Thermal Monitoring Circuit
To meet Intel's VR12/IMVP7 specification, platform users
have to set the TSEN voltage to meet the temperature
variation of VR from 75% to 100% VR max temperature.
For example, if the VR max temperature is 100°C, platform
users have to set the TSEN voltage to be 1.4875V when
VR temperature reaches 75°C and 1.8725V when VR
temperature reaches 100°C. Detailed voltage setting
versus temperature variation is shown in Table 2.
Thermometer code is implemented in the Temperature
Zone register.
Table 2. Temperature Zone Register
Comparator Trip Points
SVID Temperatures Scaled to maximum =
VRHOT Thermal 100%
Alert Voltage Represents Assert bit
Minimum Level
b7
b6
b5
b4
b3
b2
b1
b0
100%
97% 94% 91% 88% 85% 82% 75%
1.745 1.69 1.635 1.58 1.52 1.47
1.855V 1.8V
V
V
V
V
5V
V
1.855 ≤ VTSEN
1.800 ≤ V TSEN ≤ 1.835
1.745 ≤ V TSEN ≤ 1.780
Temperature_Zone
Register Content
1111_1111
0111_1111
0011_1111
1.690 ≤ V TSEN ≤ 1.725
1.635 ≤ V TSEN ≤ 1.670
1.580 ≤ V TSEN ≤ 1.615
1.525 ≤ V TSEN ≤ 1.560
0001_1111
0000_1111
0000_0111
0000_0011
1.470 ≤ V TSEN ≤ 1.505
V TSEN < 1.470
0000_0001
0000_0000
TSEN Pin Voltage
DS8167B-00
October 2011
RT8167B
The RT8167B supports two temperature reporting,
VRHOT(hardware reporting) and ALERT(software
reporting), to fulfill VR12/IMVP7 specification. VRHOT is
an open-drain structure which sends out active-low VRHOT
signals. When TSEN voltage rises above 1.855V (100%
of VR temperature), the VRHOT signal will be set to low.
When TSEN voltage drops below 1.8V (97% of VR
temperature), the VRHOT signal will be reset to high. When
TSEN voltage rises above 1.8V (97% of VR temperature),
The RT8167B will update the bit1 data from 0 to 1 in the
Status_1 register and assert ALERT. When TSEN voltage
drops below 1.745V (94% of VR temperature), VR will
update the bit1 data from 1 to 0 in the Status_1 register
and assert ALERT.
The temperature reporting function for the GFX VR can be
disabled by pulling TSENA pin to VCC in case the
temperature reporting function for the GFX VR is not used
or the GFX VR is disabled. When the GFX VR's
temperature reporting function is disabled, the RT8167B
will reject the SVID command of getting the
Temperature_Zone register content of the GFX VR.
However, note that the temperature reporting function for
the CORE VR is always active. CORE VR's temperature
reporting function can not be disabled by pulling TSEN
pin to VCC.
VCC
ROC1
OCSETx
ROC2
Figure 14. OCP Setting without Temperature
Compensation
The current limit is triggered when inductor current
exceeds the current limit threshold ILIMIT, defined by
VOCSET. The driver will be forced to turn off UGATE until
the over current condition is cleared. If the over current
condition remains valid for 15 PWM cycles, VR will trigger
OCP latch. Latched OCP forces both UGATE and LGATE
to go low. When OCP is triggered in one of VRs, the
other VR will enter into soft shutdown sequence. The OCP
latch mechanism will be masked when VRx_READY =
low, which means that only the current limit will be active
when VOUT is ramping up to initial voltage (or VREFx).
If inductor DCR is used as the current sense component,
then temperature compensation is recommended for
protection under all conditions. Figure 15 shows a typical
OCP setting with temperature compensation.
VCC
ROC1a
Over Current Protection
The CORE/GFX VR compares a programmable current
limit set point to the voltage from the current sense amplifier
output for Over Current Protection (OCP). The voltage
applied to OCSETx pin defines the desired peak current
limit threshold ILIMIT :
VOCSET = 48 x ILIMIT x RSENSE
DS8167B-00
October 2011
ROC1b
OCSETx
ROC2
Figure 15. OCP Setting with Temperature Compensation
(17)
Connect a resistive voltage divider from VCC to GND, with
the joint of the resistive divider connected to OCSET pin
as shown in Figure 14. For a given ROC2, then
⎛ VCC
⎞
ROC1 = ROC2 × ⎜
− 1⎟
V
⎝ OCSET
⎠
NTC
(18)
Usually, ROC1a is selected to be equal to the thermistor's
nominal resistance at room temperature. Ideally, VOCSET
is assumed to have the same temperature coefficient as
RSENSE (Inductor DCR) :
VOCSET, HOT
RSENSE, HOT
=
VOCSET, COLD RSENSE, COLD
(19)
www.richtek.com
35
RT8167B
According to the basic circuit calculation, VOCSET can be
obtained at any temperature :
VOCSET, T = VCC ×
ROC2
ROC1a / /RNTC, T + ROC1b + ROC2
(20)
Re-write (19) from (20), to get VOCSET at room temperature
ROC1a // RNTC, COLD + ROC1b + ROC2
RSENSE, HOT
=
ROC1a // RNTC, HOT + ROC1b + ROC2
RSENSE, COLD
(21)
VOCSET, 25 =
VCC ×
ROC2
ROC1a / /RNTC, 25 + ROC1b + ROC2
(22)
Solving (21) and (22) yields ROC1b and ROC2
ROC2 =
α × REQU, HOT − REQU, COLD + (1 − α ) × REQU, 25
VCC
× (1 − α )
VOCSET, 25
(23)
ROC1b =
(α − 1) × R2 + α × REQU, HOT − REQU, COLD
(1 − α )
During OVP latch state, both CORE/GFX VRs also monitor
ISENxN pin for negative voltage protection. Since the OVP
latch will continuously turn on low side MOSFET of VR,
VR may suffer negative output voltage. Therefore, when
the voltage of ISENxN drops below −0.05V after triggering
OVP, VR will turn off low side MOSFETs while high side
MOSFETs remain off. The NVP function will be active only
after OVP is triggered.
Under Voltage Protection (UVP)
Both CORE/GFX VR implement Under Voltage Protection
(UVP). If ISENxN is less than VREFx by 300mV + VOFFSET,
VR will trigger UVP latch. The UVP latch will turn off both
high side and low side MOSFETs. When UVP is triggered
by one of the VRs, the other VR will enter into soft
shutdown sequence. The UVP mechanism is masked
when VRx_READY = low.
Under Voltage Lock Out (UVLO)
(24)
where
α=
RSENSE, HOT
DCR25 × [1 + 0.00393 × (THOT − 25)]
=
RSENSE, COLD DCR25 × [1 + 0.00393 × (TCOLD − 25)]
(25)
REQU, T = ROC1a // RNTC, T
Negative Voltage Protection (NVP)
(26)
During normal operation, if the voltage at the VCC pin
drops below UVLO falling edge threshold, both VR will
trigger UVLO. The UVLO protection forces all high side
MOSFETs and low side MOSFETs off to turn off.
Inductor Selection
The switching frequency and ripple current determine the
inductor value as follows :
V − VOUT
LMIN = IN
×t
(27)
IRipple(MAX) ON
Over Voltage Protection (OVP)
The over voltage protection circuit of CORE/GFX VR
monitors the output voltage via the ISENxN pin. The
supported maximum operating VID of VR (V(MAX)) is stored
in the Vout_Max register. Once VISENxN exceeds “V(MAX)
+ 200mV”, OVP is triggered and latched. VR will try to
turn on low side MOSFETs and turn off high side
MOSFETs to protect CPU. When OVP is triggered by
the one of the VRs, the other VR will enter soft shutdown
sequence. A 10μs delay is used in OVP detection circuit
to prevent false trigger.
www.richtek.com
36
where tON is the UGATE turn on period.
Higher inductance induces less ripple current and hence
higher efficiency. However, the tradeoff is a slower transient
response of the power stage to load transients. This might
increase the need for more output capacitors, thus driving
up the cost. Find a low-loss inductor having the lowest
possible DC resistance that fits in the allotted dimensions.
The core must be large enough not to be saturated at the
peak inductor current.
DS8167B-00
October 2011
RT8167B
Output Capacitor Selection
Output capacitors are used to obtain high bandwidth for
the output voltage beyond the bandwidth of the converter
itself. Usually, the CPU manufacturer recommends a
capacitor configuration. Two different kinds of output
capacitors can be found, bulk capacitors closely located
to the inductors and ceramic output capacitors in close
proximity to the load. Latter ones are for mid-frequency
decoupling with very small ESR and ESL values while the
bulk capacitors have to provide enough stored energy to
overcome the low-frequency bandwidth gap between the
regulator and the CPU.
`
The capacitor connected to the ISEN1N/ISENAN for noise
decoupling is optional and it should also be placed close
to the ISEN1N/ISENAN pin.
`
The NTC thermistor should be placed physically close
to the inductor for better DCR thermal compensation.
Layout Consideration
Careful PC board layout is critical to achieving low
switching losses and clean, stable operation. The
switching power stage requires particular attention. If
possible, mount all of the power components on the top
side of the board with their ground terminals flushed
against one another. Follow these guidelines for optimum
PC board layout :
`
Keep the high current paths short, especially at the
ground terminals.
`
Keep the power traces and load connections short. This
is essential for high efficiency.
`
When trade-offs in trace lengths must be made, it's
preferable to allow the inductor charging path to be made
longer than the discharging path.
`
Place the current sense component close to the
controller. ISENxP and ISENxN connections for current
limit and voltage positioning must be made using Kelvin
sense connections to guarantee the current sense
accuracy. The PCB trace from the sense nodes should
be parallel to the controller.
`
Route high-speed switching nodes away from sensitive
analog areas (COMPx, FBx, ISENxP, ISENxN, etc...)
`
Special attention should be paid in placing the DCR
current sensing components. The DCR current sensing
capacitor and resistors must be placed close to the
controller.
DS8167B-00
October 2011
www.richtek.com
37
RT8167B
Outline Dimension
D
SEE DETAIL A
D2
L
1
E2
E
e
b
1
1
2
2
DETAIL A
Pin #1 ID and Tie Bar Mark Options
A
A3
A1
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
0.700
0.800
0.028
0.031
A1
0.000
0.050
0.000
0.002
A3
0.175
0.250
0.007
0.010
b
0.150
0.250
0.006
0.010
D
4.950
5.050
0.195
0.199
D2
3.250
3.500
0.128
0.138
E
4.950
5.050
0.195
0.199
E2
3.250
3.500
0.128
0.138
e
L
0.400
0.350
0.016
0.450
0.014
0.018
W-Type 40L QFN 5x5 Package
Richtek Technology Corporation
Richtek Technology Corporation
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
5F, No. 95, Minchiuan Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)86672399 Fax: (8862)86672377
Email: [email protected]
Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit
design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be
guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.
www.richtek.com
38
DS8167B-00
October 2011