Intersil ISL6363IRTZ Multiphase pwm regulator for vr12â ¢ desktop cpus Datasheet

Multiphase PWM Regulator for VR12™ Desktop CPUs
ISL6363
Features
Fully compliant with VR12™ specifications, the ISL6363
provides a complete solution for microprocessor core and
graphics power supplies. It provides two Voltage Regulators
(VRs) with three integrated gate drivers. The first output (VR1)
can be configured as a 4, 3, 2 or 1-phase VR while the second
output (VR2) is a 1-phase VR. The two VRs share a serial control
bus to communicate with the CPU and achieve lower cost and
smaller board area compared with a two-chip approach.
• Serial Data Bus (SVID)
• Dual Outputs:
- Configurable 4, 3, 2 or 1-phase for the 1st Output with 2
Integrated Gate Drivers
- 1-phase for the 2nd Output with Integrated Gate Driver
Based on Intersil’s Robust Ripple Regulator R3 Technology™,
the PWM modulator, compared to traditional modulators, has
faster transient settling time, variable switching frequency
during load transients and has improved light load efficiency
with its ability to automatically change switching frequency.
The ISL6363 has several other key features. Both outputs
support DCR current sensing with a single NTC thermistor for
DCR temperature compensation or accurate resistor current
sensing. Both outputs come with remote voltage sensing,
programmable VBOOT voltage, serial bus address, IMAX, TMAX,
adjustable switching frequency, OC protection and separate
power-good indicators. To reduce output capacitors, the
ISL6363 also has an additional compensation function for
PS1/2 mode and high frequency load transient compensation.
• Precision Core Voltage Regulation
- 0.5% System Accuracy Over-Temperature
- Enhanced Load Line Accuracy
• PS2 Compensation and High Frequency Load Transient
Compensation
• Differential Remote Voltage Sensing
• Lossless Inductor DCR Current Sensing
• Programmable VBOOT Voltage at Start-up
• Resistor Programmable Address, IMAX, TMAX for Both
Outputs
• Adaptive Body Diode Conduction Time Reduction
Applications
• VR12 Desktop Computers
Related Literature
• ISL6363EVAL1Z User Guide
1.15
VCORE (V)
1.10
VCORE
50mV/DIV
1.7mΩ LOADLINE
1.05
1.1V - PS1
1.00
1.1V - PS0
COMP
1V/DIV
0.95
65A STEP LOAD
1V/DIV
0.90
0
FIGURE 1. FAST TRANSIENT RESPONSE
September 29, 2011
FN6898.0
1
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85
IOUT (A)
2µs/DIV
FIGURE 2. ACCURATE LOADLINE, VCORE vs IOUT
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas Inc. 2011. All Rights Reserved
Intersil (and design) and R3 Technology are trademarks owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
ISL6363
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
TEMP. RANGE
(°C)
PART MARKING
PACKAGE
(Pb-Free)
PKG.
DWG. #
ISL6363CRTZ
ISL6363 CRTZ
0 to +70
48 Ld 6x6 TQFN
L48.6x6
ISL6363IRTZ
ISL6363 IRTZ
-40 to +85
48 Ld 6x6 TQFN
L48.6x6
NOTES:
1. Add “-T*” suffix for tape and reel. Please refer to TB347 for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte
tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil
Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level (MSL), please see device information page for ISL6363. For more information on MSL please see techbrief TB363.
Pin Configuration
PWM4
PWM3
PHASE2
BOOT2
UGATE2
LGATE2
PVCC
LGATE1
UGATE1
BOOT1
PHASE1
ADDR
ISL6363
(48 LD TQFN)
TOP VIEW
48 47 46 45 44 43 42 41 40 39 38 37
36 PHASEG
SCOMP 1
Temporary Pinout
Subject to Change
PGOOD 2
VCC 3
ISUMP 4
35 UGATEG
34 BOOTG
33 LGATEG
ISUMN 5
32 PVCCG
GND PAD
(BOTTOM)
ISEN1 6
31 VR_HOT#
ISEN2 7
30 NTCG
ISEN3 8
29 ISUMNG
ISEN4 9
28 ISUMPG
VSEN 10
27 RTNG
PSICOMP 11
26 FBG
RTN 12
25 COMPG
VWG
IMONG
PGOODG
SCLK
ALERT#
SDA
IMON
VR_ON
VW
NTC
FB
COMP
13 14 15 16 17 18 19 20 21 22 23 24
Pin Descriptions
ISL6363
SYMBOL
DESCRIPTION
Bottom
Pad
GND
1
SCOMP
This pin is a placeholder for potential future functionality. This pin can be left floating.
2
PGOOD
Power-good open-drain output indicating when VR1 is able to supply a regulated voltage. Pull-up externally with a 680Ω
resistor to +5V or 1kΩ to +3.3V.
3
VCC
4, 5
ISUMP,
ISUMN
VR1 current sense input pins for current monitoring, droop current and overcurrent detection.
6
ISEN1
VR1 phase 1 current sense input pin for phase current balancing.
7
ISEN2
VR1 phase 2 current sense input pin for phase current balancing.
8
ISEN3
VR1 phase 3 current sense input pin for phase current balancing.
Common ground signal of the IC. Unless otherwise stated, signals are referenced to the GND pin. The pad should also be
used as the thermal pad for heat dissipation.
+5V bias supply pin. Connect a high quality 0.1µF capacitor from this pin to GND and place it as close to the pin as possible.
A small resistor (2.2Ω for example) between the +5V supply and the decoupling capacitor is recommended.
2
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ISL6363
Pin Descriptions
(Continued)
ISL6363
SYMBOL
DESCRIPTION
9
ISEN4
VR1 phase 4 current sense input pin for phase current balancing.
10
VSEN
VR1 remote core voltage sense input.
11
PSICOMP
12
RTN
13
FB
14
COMP
15
VW
A resistor from this pin to COMP programs the PWM switching frequency for VR1.
16
NTC
One of the thermistor network inputs to the thermal monitoring circuit used to control the VR_HOT# signal. Use this pin to
monitor the temperature of VR1. Place the NTC close to the desired thermal detection point on the PCB.
17
IMON
Current monitoring output pin for VR1. The current sense signal from ISUMN and ISUMP is output on this pin to generate a
voltage proportional to the output current of VR1.
18
VR_ON
Enable input signal for the controller. A high level logic signal on this pin enables the controller and initiates soft-start for VR1
and VR2.
19, 20, 21
SDA,
ALERT#,
SCLK
Data, alert and clock signal for the SVID communication bus between the CPU and VR1 and VR2.
22
PGOODG
Power-good open-drain output indicating when VR2 is able to supply a regulated voltage. Pull-up externally with a 680Ω
resistor to +5V or 1.0kΩ to 3.3V.
23
IMONG
24
VWG
25
COMPG
26
FBG
27
RTNG
28, 29
ISUMPG,
ISUMNG
30
NTCG
31
VR_HOT#
32
PVCCG
Input voltage bias for the internal gate driver for VR2. Connect +12V to this pin. Decouple with at least a 1µF MLCC capacitor
and place it as close to the pin as possible.
33
LGATEG
Output of the VR2 low-side MOSFET gate driver. Connect this pin to the gate of the VR2 low-side MOSFET.
34
BOOTG
Connect a MLCC capacitor from this pin to the PHASEG pin. The boot capacitor is charged through an internal boot diode
connected from the PVCCG pin to the BOOTG pin.
35
UGATEG
Output of the VR2 high-side MOSFET gate drive. Connect this pin to the gate of the VR2 high-side MOSFET.
36
PHASEG
Current return path for the VR2 high-side MOSFET gate driver. Connect this pin to the node connecting the source of the
high-side MOSFET, the drain of the low-side MOSFET and the output inductor of VR2.
37
PWM4
PWM output for phase 4 of VR1. When PWM4 is pulled to +5V VCC, the controller will disable phase 4 of VR1.
38
PWM3
PWM output for phase 3 of VR1. When PWM3 is pulled to +5V VCC, the controller will disable phase 3 of VR1.
39
PHASE2
Current return path for the VR1 phase 2 high-side MOSFET gate driver. Connect this pin to the node connecting the source of
the high-side MOSFET, the drain of the low-side MOSFET and the output inductor of phase 2.
40
UGATE2
Output of the VR1 phase 2 high-side MOSFET gate drive. Connect this pin to the gate of the high-side MOSFET of phase 2.
This pin is used for improving transient response in PS2/3 mode of VR1 by switching in an additional type 3 compensation
network to improve system gain and phase margin. Connect a resistor and capacitor from this pin to the output of VR1 near
the feedback compensation network.
VR1 remote voltage sensing return input. Connect this pin to the remote ground sensing location.
Inverting input of the error amplifier for VR1.
This is a dual function pin. This pin is the output of the error amplifier for VR1. A resistor connected from this pin to GND
programs IMAX for VR1 and VBOOT for both VR1 and VR2. Refer to Table 7 on page 28.
Current monitoring output pin for VR2. The current sense signal from ISUMNG and ISUMPG is output on this pin to generate
a voltage proportional to the output current of VR2.
A resistor from this pin to COMPG programs the PWM switching frequency for VR1.
This is a dual function pin. This pin is the output of the error amplifier for VR2. A resistor connected from this pin to GND
programs IMAX for VR2 and TMAX for both VR1 and VR2. Refer to Table 8 on page 28.
Inverting input of the error amplifier for VR2.
VR2 remote voltage sensing return input. Connect this pin to the remote ground sensing location.
VR2 current sense input pin for current monitoring, droop current and overcurrent detection.
One of the thermistor network inputs to the thermal monitoring circuit used to control the VR_HOT# signal. Use this pin to
monitor the temperature of VR2. Place the NTC close to the desired thermal detection point on the PCB.
Open drain thermal overload output indicator.
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ISL6363
Pin Descriptions
(Continued)
ISL6363
SYMBOL
DESCRIPTION
41
BOOT2
Connect an MLCC capacitor from this pin to the PHASE2 pin. The boot capacitor is charged through an internal boot diode
connected from the PVCCG pin to the BOOTG pin.
42
LGATE2
Output of the VR1 phase 2 low-side MOSFET gate driver. Connect this pin to the gate of the low-side MOSFET of phase 2.
43
PVCC
44
LGATE1
Output of the VR1 phase 1 low-side MOSFET gate driver. Connect this pin to the gate of the low-side MOSFET of phase 1.
45
BOOT1
Connect an MLCC capacitor from this pin to the PHASE1 pin. The boot capacitor is charged through an internal boot diode
connected from the PVCC pin to the BOOT1 pin.
46
UGATE1
Output of the VR1 phase 1 high-side MOSFET gate drive. Connect this pin to the gate of the high-side MOSFET of phase 1.
47
PHASE1
Current return path for the VR1 phase 1 high-side MOSFET gate driver. Connect this pin to the node connecting the source of
the high-side MOSFET, the drain of the low-side MOSFET and the output inductor of phase 1.
48
ADDR
Input voltage bias for the internal gate drivers for VR1. Connect +12V to this pin. Decouple with at least a 1µF MLCC capacitor
and place it as close to the pin as possible.
A resistor from this pin to GND programs the SVID address for VR1 and VR2. Refer to Table 9 on page 28.
4
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ISL6363
Block Diagram
VWG
COMPG
COMPG
+
RTNG
Σ
+
+
E/A
_
FBG
VR2
MODULATOR
IDROOPG
ISUMPG
+
ISUMNG
_
BOOTG
DRIVER
UGATEG
PHASEG
CURRENT
SENSE
DRIVER
LGATEG
PGOODG
IMONG
OC FAULT
OV FAULT
NTCG
VCC
T_MONITOR
TEMP
MONITOR
NTC
PVCCG
VR_HOT#
COMPG
IMAX
VBOOT
TMAX
SET (A/D)
ADDR
ADDR
PVCC
COMP
VR_ON
SDA
DIGITAL
INTERFACE
ALERT#
A/D
IMONG
IMON
D/A
DAC2
DAC1
MODE
SCLK
SCOMP
PWM4
PWM3
MODE2
MODE1
BOOT2
VREADY
DRIVER
VW
PHASE2
COMP
COMP
+
RTN
FB
PSICOMP
Σ
+
VR1
MODULATOR
+
_
PSICOMP
CIRCUIT
E/A
DRIVER
+
ISUMN
_
BOOT1
CURRENT
SENSE
UGATE1
PHASE1
ISEN4
ISEN2
LGATE2
IDROOP
DRIVER
ISUMP
ISEN3
UGATE2
DRIVER
CURRENT
BALANCING
OC FAULT
ISEN1
LGATE1
PGOOD
IBAL FAULT
VSEN
OV FAULT
IMON
5
GND
FN6898.0
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ISL6363
Simplified Application Circuit
Vin +12V
+5V
VCC
Rntcg
PVCC
PVCCG
BOOTG
NTCG
oC
LG
UGATEG
PGOODG
PGOODG
Rfsetg
PHASEG
GX Vcore
LGATEG
VWG
Rsumg
ISUMPG
Rprog2
Rng
COMPG
oC
Cng
Rig
Vsumng
ISUMNG
VCC
UGATE
Rdroopg
PVCC
VCCSENSEG
VSSSENSEG
SDA
ALERT#
SCLK
+12V
ISL6363
VCC
UGATE
SDA
ALERT#
SCLK
PVCC
L3
PHASE
ISL6622
BOOT
LGATE
GND
PWM3
Rscomp
PWM
SCOMP
Raddr
L4
PHASE
BOOT
PWM LGATE
GND
PWM4
IMONG
IMONG
Vin
+12V
ISL6622
RTNG
BOOT2
ADDR
UGATE2
Rntc
NTC
oC
VR_HOT#
PGOOD
VR_ON
Cvsumng
+12V
FBG
CPU Vcore
LGATE2
VR_HOT#
PGOOD
VR_ON
Rfset
L2
PHASE2
BOOT1
L1
UGATE1
VW
PHASE1
Rprog1
LGATE1
COMP
Rsum4
ISUMP
Rn
FB
Cn
Rsum2
Rsum1
PSICOMP
Ri
ISUMN
Vsumn
Cvsumv
Cisen1 Cisen2 Cisen3Cisen4 Risen4
Rdroop
ISEN4
VCCSENSE
VSSSENSE
oC
Rsum3
IMON
VSEN
ISEN3
RTN
ISEN2
IMON
6
GND
ISEN1
Risen3
Risen2
Risen1
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ISL6363
Table of Contents
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Electrical Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Gate Driver Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Multiphase R3 Modulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Start-up Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Regulation and Load Line Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential Voltage Sensing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Phase Current Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dynamic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VR_HOT#/ALERT# Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protection Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PSICOMP Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adaptive Body Diode Conduction Time Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Supported Data and Configuration Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
11
13
13
17
17
19
19
20
20
21
21
21
Key Component Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Inductor DCR Current-Sensing Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Resistor Current-Sensing Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compensator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming Resistors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NTC Network on the NTC and the NTCG pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Current Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Slew Rate Compensation Circuit for 1-Tick VID Transition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
22
24
25
25
28
29
29
29
29
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
7
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Absolute Maximum Ratings
Thermal Information
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +7V
Supply Voltage, PVCC, PVCCG . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 15V
Absolute Boot Voltage (BOOT). . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +36V
Phase Voltage (PHASE) . . . . . . . . . . . . . . . . . . -8V (<400ns, 20µJ) to +30V,
(<200ns, VBOOT - VGND < +36V)
UGATE Voltage (UGATE) . . . . . . . . . . . . . . . . . . PHASE-0.3V to BOOT + 0.3V
PHASE-3.5V (<100ns Pulse Width, 2µJ) to BOOT + 0.3V
LGATE Voltage . . . . . . . . . . . . -3V (<20ns Pulse Width, 5µJ) to PVCC + 0.3V
-5V (<100ns Pulse Width, 2µJ) to PVCC + 0.3V
All Other Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to (VCC + 0.3V)
Open Drain Outputs, PGOOD, VR_HOT#, ALERT#. . . . . . . . . . -0.3V to +7V
ESD Rating
Human Body Model (Tested per JESD22-A114E) . . . . . . . . . . . . . . 2500V
Machine Model (Tested per JESD22-A115-A) . . . . . . . . . . . . . . . . . 250V
Charged Device Model (Tested per JESD22-C101A) . . . . . . . . . . 1000V
Latch Up (Tested per JESD-78B; Class 2, Level A) . . . . . . . . . . . . . . 100mA
Thermal Resistance (Typical)
θJA (°C/W) θJC (°C/W)
48 Ld TQFN Package (Notes 4, 5) . . . . . . .
27
1
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . .+150°C
Maximum Storage Temperature Range . . . . . . . . . . . . . .-65°C to +150°C
Maximum Junction Temperature (Plastic Package) . . . . . . . . . . . .+150°C
Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Pb-Free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
Recommended Operating Conditions
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5V ±5%
PVCC, PVCCG Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5V to 12V
Ambient Temperature
CRTZ (Commercial) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C
IRTZ (Industrial) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40°C to +85°C
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product
reliability and result in failures not covered by warranty.
NOTES:
4. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech
Brief TB379.
5. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside.
Electrical Specifications
Operating Conditions: VCC = 5V, PVCC = 12V, PVCCG = 12V, TA = 0°C to +70°C, (Commercial) or
-40°C to +85°C (Industrial), fSW = 300kHz, unless otherwise noted.
Boldface limits apply over the operating temperature range, 0°C to +70°C (Commercial) or -40°C to +85°C (Industrial).
PARAMETER
TYP
MAX
(Note 6)
UNITS
VR_ON = 1V
18
20
mA
VR_ON = 0V
4.1
5.5
mA
VR_ON = 1V
1
2
mA
1
mA
2
mA
1
mA
4.5
V
SYMBOL
TEST CONDITIONS
MIN
(Note 6)
INPUT POWER SUPPLY
+5V Supply Current
IVCC
PVCC Supply Current
IPVCC
PVCCG Supply Current
IPVCCG
VR_ON = 0V
VR_ON = 1V
1
VR_ON = 0V
VCC Power-On-Reset Threshold
PVCC and PVCCG Power-On-Reset
Threshold
PORr
VCC rising
PORf
VCC falling
PPORr
VCC rising
PPORf
VCC falling
CRTZ
No load; closed loop, active mode range
VID = 0.75V to 1.52V
4.35
4
4.15
4.35
4
V
4.5
4.15
V
V
SYSTEM AND REFERENCES
System Accuracy
IRTZ
Internal VBOOT
8
-0.5
+0.5
%
VID = 0.5V to 0.745V
-8
+8
mV
VID = 0.25V to 0.495V
-15
+15
mV
No load; closed loop, active mode range
VID = 0.75V to 1.52V
-0.8
+0.8
%
VID = 0.5V to 0.745V
-10
+10
mV
VID = 0.25V to 0.495V
-18
+18
mV
CRTZ
1.0945 1.100 1.1055
V
IRTZ
1.0912
V
1.1
1.1088
FN6898.0
September 29, 2011
ISL6363
Electrical Specifications
Operating Conditions: VCC = 5V, PVCC = 12V, PVCCG = 12V, TA = 0°C to +70°C, (Commercial) or
-40°C to +85°C (Industrial), fSW = 300kHz, unless otherwise noted.
Boldface limits apply over the operating temperature range, 0°C to +70°C (Commercial) or -40°C to +85°C (Industrial). (Continued)
PARAMETER
SYMBOL
Maximum Output Voltage
TEST CONDITIONS
MIN
(Note 6)
TYP
MAX
(Note 6)
UNITS
VCC_CORE(max)
VID = [11111111]
1.52
V
Minimum Output Voltage
VCC_CORE(min)
VID = [00000001]
0.25
V
Maximum Output Voltage with Offset
VCC_CORE(max)
+ Offset
Register 33h = 7Fh, VID = FFh
2.155
V
CHANNEL FREQUENCY
Nominal Channel Frequency
fSW(nom)
Rfset = 8.06kΩ, 3-channel operation,
VCOMP = 1.1V
280
300
Minimum Adjustment Range
Maximum Adjustment Range
320
kHz
200
kHz
+0.313
mV
500
AMPLIFIERS
IFB = 0A
Current-Sense Amplifier Input Offset
Error Amp DC Gain
Av0
Error Amp Gain-Bandwidth Product
GBW
CL = 20pF
-0.313
90
dB
18
MHz
ISEN
Imbalance Voltage
Maximum of ISENs - Minimum of ISENs
Input Bias Current
1.1
20
mV
nA
POWER-GOOD AND PROTECTION MONITORS
PGOOD Low Voltage
VOL
IPGOOD = 4mA
PGOOD Leakage Current
IOH
PGOOD = 3.3V
PGOOD Delay
tpgd
0.15
0.4
V
1
µA
3.8
ms
ALERT# Low Resistance
7
13
Ω
VR_HOT# Low Resistance
7
13
Ω
ALERT# Leakage Current
1
µA
VR_HOT# Leakage Current
1
µA
GATE DRIVE SWITCHING TIME
UGATE Rise Time
tRUGATE; VPVCC /VPVCCG = 12V, 3nF load,
10% to 90%
26
ns
LGATE Rise Time
tRLGATE; VPVCC = 12V, 3nF load, 10% to 90%
18
ns
UGATE Fall Time
tFUGATE; VPVCC = 12V, 3nF load, 90% to 10%
18
ns
LGATE Fall Time
tFLGATE; VPVCC = 12V, 3nF load, 90% to 10%
12
ns
UGATE Turn-On Non-Overlap
tPDHUGATE; VPVCC = 12V, 3nF load, adaptive
10
ns
LGATE Turn-On Non-Overlap
tPDHLGATE; VPVCC = 12V, 3nF load, adaptive
10
ns
GATE DRIVE RESISTANCE
Upper Drive Source Resistance
VPVCC = 12V, 15mA source current
2.0
W
Upper Drive Sink Resistance
VPVCC = 12V, 15mA sink current
1.35
W
Lower Drive Source Resistance
VPVCC = 12V, 15mA source current
1.35
W
Lower Drive Sink Resistance
VPVCC = 12V, 15mA sink current
0.90
W
BOOTSTRAP DIODE
Forward Voltage
VF
PVCC = 12V, IF = 2mA
0.58
V
Reverse Leakage
IR
VR = 25V
0.2
µA
9
FN6898.0
September 29, 2011
ISL6363
Electrical Specifications
Operating Conditions: VCC = 5V, PVCC = 12V, PVCCG = 12V, TA = 0°C to +70°C, (Commercial) or
-40°C to +85°C (Industrial), fSW = 300kHz, unless otherwise noted.
Boldface limits apply over the operating temperature range, 0°C to +70°C (Commercial) or -40°C to +85°C (Industrial). (Continued)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
(Note 6)
TYP
MAX
(Note 6)
UNITS
232
mV
PROTECTION
Overvoltage Threshold
OVH
VSEN rising above setpoint for >1µs
Current Imbalance Threshold
One ISEN above another ISEN for >1.2ms
VR1 Overcurrent Threshold
4, 3, 2, 1-Phase Configuration PS0 Mode
116
9
50
4-Phase Configuration, drop to 2-Phase in PS1
Mode
4-Phase Configuration, drop to 1-Phase in PS2/3
Mode
16
20
16
20
All modes of operation
26
µA
26
µA
µA
30
50
60
µA
µA
40
2-Phase Configuration, drop to 1-phase in
PS1/2/3 Mode
VR2 Overcurrent Threshold
71
30
3-Phase Configuration, drop to 2-Phase in PS1
3-Phase Configuration, drop to 1-Phase in PS2/3
60
mV
µA
71
µA
0.3
V
LOGIC THRESHOLDS
VR_ON Input Low
VIL
VR_ON Input High
VIH
0.7
V
PWM
PWM Output Low
V0L
Sinking 5mA
PWM Output High (Note 6)
V0H
Sourcing 5mA
PWM Tri-State Leakage
1.0
3.5
PWM = 2.5V
V
4.2
V
2
µA
THERMAL MONITOR
NTC Source Current
NTC = 1.3V
58
60
63
µA
VR_HOT# Trip Voltage (VR1 and VR2)
Falling
0.86
0.873
0.89
V
VR_HOT# Reset Voltage (VR1 and VR2)
Rising
0.905
0.929
0.935
V
Therm_Alert Trip Voltage (VR1 and VR2)
Falling
0.9
0.913
0.93
V
Therm_Alert Reset Voltage (VR1 and VR2)
Rising
0.945
0.961
0.975
V
147
150
154
µA
CURRENT MONITOR
IMON Output Current (VR1 and VR2)
ISUM- pin current = 25µA
ICCMAX_Alert Trip Voltage (VR1 and VR2)
Rising
2.61
2.66
2.695
V
ICCMAX_ALERT Reset Voltage (VR1 and VR2)
Falling
2.585
2.62
2.650
V
-1
0
INPUTS
VR_ON Leakage Current
IVR_ON
VR_ON = 0V
VR_ON = 1V
SCLK, SDA Leakage
VR_ON = 0V, SCLK and SDA = 0V and 1V
18
-1
VR_ON = 1V, SCLK and SDA = 1V
-5
VR_ON = 1V, SCLK and SDA = 0V
-85
-60
µA
35
µA
1
µA
1
µA
-30
µA
SLEW RATE (For VID Change)
Fast Slew Rate
10
mV/µs
Slow Slew Rate
2.5
mV/µs
NOTE:
6. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design.
10
FN6898.0
September 29, 2011
ISL6363
Gate Driver Timing Diagram
PWM
tLGFUGR
tFU
tRU
1V
UGATE
1V
LGATE
tRL
tFL
tUGFLGR
Theory of Operation
Multiphase R3 Modulator
The ISL6363 is a multiphase regulator implementing Intel’s™
VR12™ protocol. It has two voltage regulators, VR1 and VR2, on
one chip. VR1 can be programmed for 1, 2, 3, or 4-phase
operation, and VR2 is dedicated for 1-phase operation. The
following description is based on VR1, but also applies to VR2
because the same architecture is implemented.
The ISL6363 uses Intersil’s patented R3 (Robust Ripple Regulator)
modulator. The R3 modulator combines the best features of fixed
frequency PWM and hysteretic PWM while eliminating many of
their shortcomings. Figure 3 conceptually shows the multiphase
R3 modulator circuit, and Figure 4 shows the operation principles.
A current source flows from the VW pin to the COMP pin, creating
a voltage window set by the resistor between the two pins. This
voltage window is called VW window in the following discussion.
Inside the IC, the modulator uses the master clock circuit to
generate the clocks for the slave circuits. The modulator
discharges the ripple capacitor Crm with a current source equal to
gmVo, where gm is a gain factor. Crm voltage Vcrm is a sawtooth
waveform traversing between the VW and COMP voltages. It resets
to VW when it hits COMP, and generates a one-shot master clock
signal. A phase sequencer distributes the master clock signal to
the slave circuits. If VR1 is in 4-phase mode, the master clock
signal will be distributed to the four phases, and the Clock1~4
signals will be 90° out-of-phase. If VR1 is in 3-phase mode, the
master clock signal will be distributed to the three phases, and the
Clock1~3 signals will be 120° out-of-phase. If VR1 is in 2-phase
mode, the master clock signal will be distributed to Phases 1 and 2,
and the Clock1 and Clock2 signals will be 180° out-of-phase. If
VR1 is in 1-phase mode, the master clock signal will be distributed
to Phase 1 only and be the Clock1 signal.
11
MASTER CLOCK CIRCUIT
MASTER
CLOCK
COMP
Phase
Vcrm
Sequencer
VW
MASTER
CLOCK
gmVo
Clock1
Clock2
Clock3
Crm
SLAVE CIRCUIT 1
VW
Clock1
S
R
Q
PWM1 Phase1
L1
IL1
Vcrs1
Vo
Co
gm
Crs1
SLAVE CIRCUIT 2
VW
Clock2
S
R
Q
PWM2 Phase2
L2
IL2
Vcrs2
gm
Crs2
SLAVE CIRCUIT 3
VW
Clock3
S
R
Q
PWM3 Phase3
L3
IL3
Vcrs3
gm
Crs3
FIGURE 3. R3 MODULATOR CIRCUIT
Each slave circuit has its own ripple capacitor Crs, whose voltage
mimics the inductor ripple current. A gm amplifier converts the
inductor voltage into a current source to charge and discharge
Crs. The slave circuit turns on its PWM pulse upon receiving the
clock signal, and the current source charges Crs. When Crs
voltage VCrs hits VW, the slave circuit turns off the PWM pulse,
and the current source discharges Crs.
FN6898.0
September 29, 2011
ISL6363
VW
VW
Hysteretic
Window
Vcrm
COMP
COMP
Vcrm
Master
Clock
Master
Clock
Clock1
Clock1
PWM1
PWM1
Clock2
Clock2
PWM2
PWM2
Clock3
Clock3
PWM3
PWM3
VW
VW
Vcrs2
Vcrs3
Vcrs1
Vcrs3
Vcrs2
Vcrs1
FIGURE 4. R3 MODULATOR OPERATION PRINCIPLES IN STEADY
STATE
Since the controller works with Vcrs, which are large-amplitude
and noise-free synthesized signals, it achieves lower phase jitter
than conventional hysteretic mode and fixed PWM mode
controllers. Unlike conventional hysteretic mode converters, the
ISL6363 uses an error amplifier that allows the controller to
maintain a 0.5% output voltage accuracy.
Figure 5 shows the operation principles during load insertion
response. The COMP voltage rises during load insertion,
generating the master clock signal more quickly, so the PWM
pulses turn on earlier, increasing the effective switching frequency,
which allows for higher control loop bandwidth than conventional
fixed frequency PWM controllers. The VW voltage rises as the
COMP voltage rises, making the PWM pulses wider. During load
release response, the COMP voltage falls. It takes the master clock
circuit longer to generate the next master clock signal so the PWM
pulse is held off until needed. The VW voltage falls as the COMP
voltage falls, reducing the current PWM pulse width. This kind of
behavior gives the ISL6363 excellent response speed.
The fact that all the phases share the same VW window voltage
also ensures excellent dynamic current balance among phases.
FIGURE 5. R3 MODULATOR OPERATION PRINCIPLES IN LOAD
INSERTION RESPONSE
Diode Emulation and Period Stretching of the ISL6363 can
operate in diode emulation (DE) mode to improve light load
efficiency. In DE mode, the low-side MOSFET conducts when the
current is flowing from source to drain and does not allow reverse
current, emulating a diode. As Figure 6 shows, when LGATE is on,
the low-side MOSFET carries current, creating negative voltage on
the phase node due to the voltage drop across the ON-resistance.
The ISL6363 monitors the current through monitoring the phase
node voltage. It turns off LGATE when the phase node voltage
reaches zero to prevent the inductor current from reversing the
direction and creating unnecessary power loss.
PHASE
UGATE
LGATE
IL
FIGURE 6. DIODE EMULATION
If the load current is light enough, as Figure 6 shows, the inductor
current will reach and stay at zero before the next phase node
pulse, and the regulator is in discontinuous conduction mode
(DCM). If the load current is heavy enough, the inductor current
will never reach 0A, and the regulator is in CCM although the
controller is in DE mode.
12
FN6898.0
September 29, 2011
ISL6363
Figure 7 shows the operation principle in diode emulation mode at
light load. The load gets incrementally lighter in the three cases
from top to bottom. The PWM on-time is determined by the VW
window size, therefore is the same, making the inductor current
triangle the same in the three cases. The ISL6363 clamps the
ripple capacitor voltage Vcrs in DE mode to make it mimic the
inductor current. It takes the COMP voltage longer to hit Vcrs,
naturally stretching the switching period. The inductor current
triangles move further apart from each other such that the
inductor current average value is equal to the load current. The
reduced switching frequency helps increase light load efficiency.
Voltage Regulation and Load Line
Implementation
After the start sequence, the ISL6363 regulates the output voltage
to the value set by the VID information per Table 1. The ISL6363
will control the no-load output voltage to an accuracy of ±0.5%
over the range of 0.75V to 1.52V. A differential amplifier allows
voltage sensing for precise voltage regulation at the
microprocessor die.
TABLE 1. VID TABLE
VID
CCM/DCM BOUNDARY
VW
Vcrs
iL
VW
LIGHT DCM
Vcrs
iL
VW
DEEP DCM
Vcrs
iL
FIGURE 7. PERIOD STRETCHING
Start-up Timing
With the controller's VCC voltage above the POR threshold, the
start-up sequence begins when VR_ON exceeds the logic high
threshold. Figure 8 shows the typical start-up timing of VR1 and
VR2. The ISL6363 uses digital soft-start to ramp-up DAC to the
voltage programmed by the SetVID command. PGOOD is asserted
high and ALERT# is asserted low at the end of the ramp-up.
Similar results occur if VR_ON is tied to VCC, with the soft-start
sequence starting 800µs after VCC crosses the POR threshold.
VCC
SLEW RATE
VR_ON
2.5mV/µs
VID
VID COMMAND
VOLTAGE
3.8ms
DAC
PGOOD
…...
ALERT#
FIGURE 8. VR1 SOFT-START WAVEFORMS
13
HEX
VO (V)
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
0
0.00000
0
0
0
0
0
0
0
1
0
1
0.25000
0
0
0
0
0
0
1
0
0
2
0.25500
0
0
0
0
0
0
1
1
0
3
0.26000
0
0
0
0
0
1
0
0
0
4
0.26500
0
0
0
0
0
1
0
1
0
5
0.27000
0
0
0
0
0
1
1
0
0
6
0.27500
0
0
0
0
0
1
1
1
0
7
0.28000
0
0
0
0
1
0
0
0
0
8
0.28500
0
0
0
0
1
0
0
1
0
9
0.29000
0
0
0
0
1
0
1
0
0
A
0.29500
0
0
0
0
1
0
1
1
0
B
0.30000
0
0
0
0
1
1
0
0
0
C
0.30500
0
0
0
0
1
1
0
1
0
D
0.31000
0
0
0
0
1
1
1
0
0
E
0.31500
0
0
0
0
1
1
1
1
0
F
0.32000
0
0
0
1
0
0
0
0
1
0
0.32500
0
0
0
1
0
0
0
1
1
1
0.33000
0
0
0
1
0
0
1
0
1
2
0.33500
0
0
0
1
0
0
1
1
1
3
0.34000
0
0
0
1
0
1
0
0
1
4
0.34500
0
0
0
1
0
1
0
1
1
5
0.35000
0
0
0
1
0
1
1
0
1
6
0.35500
0
0
0
1
0
1
1
1
1
7
0.36000
0
0
0
1
1
0
0
0
1
8
0.36500
0
0
0
1
1
0
0
1
1
9
0.37000
0
0
0
1
1
0
1
0
1
A
0.37500
0
0
0
1
1
0
1
1
1
B
0.38000
0
0
0
1
1
1
0
0
1
C
0.38500
0
0
0
1
1
1
0
1
1
D
0.39000
0
0
0
1
1
1
1
0
1
E
0.39500
0
0
0
1
1
1
1
1
1
F
0.40000
0
0
1
0
0
0
0
0
2
0
0.40500
FN6898.0
September 29, 2011
ISL6363
TABLE 1. VID TABLE (Continued)
TABLE 1. VID TABLE (Continued)
VID
VID
HEX
VO (V)
7
6
5
4
3
2
1
0
1
0.41000
0
1
0
0
1
0
0
1
4
9
0.61000
2
0.41500
0
1
0
0
1
0
1
0
4
A
0.61500
3
0.42000
0
1
0
0
1
0
1
1
4
B
0.62000
2
4
0.42500
0
1
0
0
1
1
0
0
4
C
0.62500
1
2
5
0.43000
0
1
0
0
1
1
0
1
4
D
0.63000
1
0
2
6
0.43500
0
1
0
0
1
1
1
0
4
E
0.63500
1
1
1
2
7
0.44000
0
1
0
0
1
1
1
1
4
F
0.64000
1
0
0
0
2
8
0.44500
0
1
0
1
0
0
0
0
5
0
0.64500
0
1
0
0
1
2
9
0.45000
0
1
0
1
0
0
0
1
5
1
0.65000
0
1
0
1
0
2
A
0.45500
0
1
0
1
0
0
1
0
5
2
0.65500
1
0
1
0
1
1
2
B
0.46000
0
1
0
1
0
0
1
1
5
3
0.66000
0
1
0
1
1
0
0
2
C
0.46500
0
1
0
1
0
1
0
0
5
4
0.66500
0
0
1
0
1
1
0
1
2
D
0.47000
0
1
0
1
0
1
0
1
5
5
0.67000
0
0
1
0
1
1
1
0
2
E
0.47500
0
1
0
1
0
1
1
0
5
6
0.67500
0
0
1
0
1
1
1
1
2
F
0.48000
0
1
0
1
0
1
1
1
5
7
0.68000
0
0
1
1
0
0
0
0
3
0
0.48500
0
1
0
1
1
0
0
0
5
8
0.68500
0
0
1
1
0
0
0
1
3
1
0.49000
0
1
0
1
1
0
0
1
5
9
0.69000
0
0
1
1
0
0
1
0
3
2
0.49500
0
1
0
1
1
0
1
0
5
A
0.69500
0
0
1
1
0
0
1
1
3
3
0.50000
0
1
0
1
1
0
1
1
5
B
0.70000
0
0
1
1
0
1
0
0
3
4
0.50500
0
1
0
1
1
1
0
0
5
C
0.70500
0
0
1
1
0
1
0
1
3
5
0.51000
0
1
0
1
1
1
0
1
5
D
0.71000
0
0
1
1
0
1
1
0
3
6
0.51500
0
1
0
1
1
1
1
0
5
E
0.71500
0
0
1
1
0
1
1
1
3
7
0.52000
0
1
0
1
1
1
1
1
5
F
0.72000
0
0
1
1
1
0
0
0
3
8
0.52500
0
1
1
0
0
0
0
0
6
0
0.72500
0
0
1
1
1
0
0
1
3
9
0.53000
0
1
1
0
0
0
0
1
6
1
0.73000
0
0
1
1
1
0
1
0
3
A
0.53500
0
1
1
0
0
0
1
0
6
2
0.73500
0
0
1
1
1
0
1
1
3
B
0.54000
0
1
1
0
0
0
1
1
6
3
0.74000
0
0
1
1
1
1
0
0
3
C
0.54500
0
1
1
0
0
1
0
0
6
4
0.74500
0
0
1
1
1
1
0
1
3
D
0.55000
0
1
1
0
0
1
0
1
6
5
0.75000
0
0
1
1
1
1
1
0
3
E
0.55500
0
1
1
0
0
1
1
0
6
6
0.75500
0
0
1
1
1
1
1
1
3
F
0.56000
0
1
1
0
0
1
1
1
6
7
0.76000
0
1
0
0
0
0
0
0
4
0
0.56500
0
1
1
0
1
0
0
0
6
8
0.76500
0
1
0
0
0
0
0
1
4
1
0.57000
0
1
1
0
1
0
0
1
6
9
0.77000
0
1
0
0
0
0
1
0
4
2
0.57500
0
1
1
0
1
0
1
0
6
A
0.77500
0
1
0
0
0
0
1
1
4
3
0.58000
0
1
1
0
1
0
1
1
6
B
0.78000
0
1
0
0
0
1
0
0
4
4
0.58500
0
1
1
0
1
1
0
0
6
C
0.78500
0
1
0
0
0
1
0
1
4
5
0.59000
0
1
1
0
1
1
0
1
6
D
0.79000
0
1
0
0
0
1
1
0
4
6
0.59500
0
1
1
0
1
1
1
0
6
E
0.79500
0
1
0
0
0
1
1
1
4
7
0.60000
0
1
1
0
1
1
1
1
6
F
0.80000
0
1
0
0
1
0
0
0
4
8
0.60500
0
1
1
1
0
0
0
0
7
0
0.80500
7
6
5
4
3
2
1
0
0
0
1
0
0
0
0
1
2
0
0
1
0
0
0
1
0
2
0
0
1
0
0
0
1
1
2
0
0
1
0
0
1
0
0
0
0
1
0
0
1
0
0
0
1
0
0
1
0
0
1
0
0
0
0
1
0
0
0
1
0
0
1
0
0
0
14
HEX
VO (V)
FN6898.0
September 29, 2011
ISL6363
TABLE 1. VID TABLE (Continued)
TABLE 1. VID TABLE (Continued)
VID
VID
HEX
VO (V)
7
6
5
4
3
2
1
0
1
0.81000
1
0
0
1
1
0
0
1
9
9
1.01000
2
0.81500
1
0
0
1
1
0
1
0
9
A
1.01500
3
0.82000
1
0
0
1
1
0
1
1
9
B
1.02000
7
4
0.82500
1
0
0
1
1
1
0
0
9
C
1.02500
1
7
5
0.83000
1
0
0
1
1
1
0
1
9
D
1.03000
1
0
7
6
0.83500
1
0
0
1
1
1
1
0
9
E
1.03500
1
1
1
7
7
0.84000
1
0
0
1
1
1
1
1
9
F
1.04000
1
0
0
0
7
8
0.84500
1
0
1
0
0
0
0
0
A
0
1.04500
1
1
0
0
1
7
9
0.85000
1
0
1
0
0
0
0
1
A
1
1.05000
1
1
0
1
0
7
A
0.85500
1
0
1
0
0
0
1
0
A
2
1.05500
1
1
1
0
1
1
7
B
0.86000
1
0
1
0
0
0
1
1
A
3
1.06000
1
1
1
1
1
0
0
7
C
0.86500
1
0
1
0
0
1
0
0
A
4
1.06500
0
1
1
1
1
1
0
1
7
D
0.87000
1
0
1
0
0
1
0
1
A
5
1.07000
0
1
1
1
1
1
1
0
7
E
0.87500
1
0
1
0
0
1
1
0
A
6
1.07500
0
1
1
1
1
1
1
1
7
F
0.88000
1
0
1
0
0
1
1
1
A
7
1.08000
1
0
0
0
0
0
0
0
8
0
0.88500
1
0
1
0
1
0
0
0
A
8
1.08500
1
0
0
0
0
0
0
1
8
1
0.89000
1
0
1
0
1
0
0
1
A
9
1.09000
1
0
0
0
0
0
1
0
8
2
0.89500
1
0
1
0
1
0
1
0
A
A
1.09500
1
0
0
0
0
0
1
1
8
3
0.90000
1
0
1
0
1
0
1
1
A
B
1.10000
1
0
0
0
0
1
0
0
8
4
0.90500
1
0
1
0
1
1
0
0
A
C
1.10500
1
0
0
0
0
1
0
1
8
5
0.91000
1
0
1
0
1
1
0
1
A
D
1.11000
1
0
0
0
0
1
1
0
8
6
0.91500
1
0
1
0
1
1
1
0
A
E
1.11500
1
0
0
0
0
1
1
1
8
7
0.92000
1
0
1
0
1
1
1
1
A
F
1.12000
1
0
0
0
1
0
0
0
8
8
0.92500
1
0
1
1
0
0
0
0
B
0
1.12500
1
0
0
0
1
0
0
1
8
9
0.93000
1
0
1
1
0
0
0
1
B
1
1.13000
1
0
0
0
1
0
1
0
8
A
0.93500
1
0
1
1
0
0
1
0
B
2
1.13500
1
0
0
0
1
0
1
1
8
B
0.94000
1
0
1
1
0
0
1
1
B
3
1.14000
1
0
0
0
1
1
0
0
8
C
0.94500
1
0
1
1
0
1
0
0
B
4
1.14500
1
0
0
0
1
1
0
1
8
D
0.95000
1
0
1
1
0
1
0
1
B
5
1.15000
1
0
0
0
1
1
1
0
8
E
0.95500
1
0
1
1
0
1
1
0
B
6
1.15500
1
0
0
0
1
1
1
1
8
F
0.96000
1
0
1
1
0
1
1
1
B
7
1.16000
1
0
0
1
0
0
0
0
9
0
0.96500
1
0
1
1
1
0
0
0
B
8
1.16500
1
0
0
1
0
0
0
1
9
1
0.97000
1
0
1
1
1
0
0
1
B
9
1.17000
1
0
0
1
0
0
1
0
9
2
0.97500
1
0
1
1
1
0
1
0
B
A
1.17500
1
0
0
1
0
0
1
1
9
3
0.98000
1
0
1
1
1
0
1
1
B
B
1.18000
1
0
0
1
0
1
0
0
9
4
0.98500
1
0
1
1
1
1
0
0
B
C
1.18500
1
0
0
1
0
1
0
1
9
5
0.99000
1
0
1
1
1
1
0
1
B
D
1.19000
1
0
0
1
0
1
1
0
9
6
0.99500
1
0
1
1
1
1
1
0
B
E
1.19500
1
0
0
1
0
1
1
1
9
7
1.00000
1
0
1
1
1
1
1
1
B
F
1.20000
1
0
0
1
1
0
0
0
9
8
1.00500
1
1
0
0
0
0
0
0
C
0
1.20500
7
6
5
4
3
2
1
0
0
1
1
1
0
0
0
1
7
0
1
1
1
0
0
1
0
7
0
1
1
1
0
0
1
1
7
0
1
1
1
0
1
0
0
0
1
1
1
0
1
0
0
1
1
1
0
1
0
1
1
1
0
0
1
1
1
0
1
1
0
1
1
0
1
0
15
HEX
VO (V)
FN6898.0
September 29, 2011
ISL6363
TABLE 1. VID TABLE (Continued)
TABLE 1. VID TABLE (Continued)
VID
VID
HEX
VO (V)
7
6
5
4
3
2
1
0
1
1.21000
1
1
1
0
1
0
0
1
E
9
1.41000
2
1.21500
1
1
1
0
1
0
1
0
E
A
1.41500
3
1.22000
1
1
1
0
1
0
1
1
E
B
1.42000
C
4
1.22500
1
1
1
0
1
1
0
0
E
C
1.42500
1
C
5
1.23000
1
1
1
0
1
1
0
1
E
D
1.43000
1
0
C
6
1.23500
1
1
1
0
1
1
1
0
E
E
1.43500
1
1
1
C
7
1.24000
1
1
1
0
1
1
1
1
E
F
1.44000
1
0
0
0
C
8
1.24500
1
1
1
1
0
0
0
0
F
0
1.44500
0
1
0
0
1
C
9
1.25000
1
1
1
1
0
0
0
1
F
1
1.45000
0
1
0
1
0
C
A
1.25500
1
1
1
1
0
0
1
0
F
2
1.45500
0
0
1
0
1
1
C
B
1.26000
1
1
1
1
0
0
1
1
F
3
1.46000
1
0
0
1
1
0
0
C
C
1.26500
1
1
1
1
0
1
0
0
F
4
1.46500
1
1
0
0
1
1
0
1
C
D
1.27000
1
1
1
1
0
1
0
1
F
5
1.47000
1
1
0
0
1
1
1
0
C
E
1.27500
1
1
1
1
0
1
1
0
F
6
1.47500
1
1
0
0
1
1
1
1
C
F
1.28000
1
1
1
1
0
1
1
1
F
7
1.48000
1
1
0
1
0
0
0
0
D
0
1.28500
1
1
1
1
1
0
0
0
F
8
1.48500
1
1
0
1
0
0
0
1
D
1
1.29000
1
1
1
1
1
0
0
1
F
9
1.49000
1
1
0
1
0
0
1
0
D
2
1.29500
1
1
1
1
1
0
1
0
F
A
1.49500
1
1
0
1
0
0
1
1
D
3
1.30000
1
1
1
1
1
0
1
1
F
B
1.50000
1
1
0
1
0
1
0
0
D
4
1.30500
1
1
1
1
1
1
0
0
F
C
1.50500
1
1
0
1
0
1
0
1
D
5
1.31000
1
1
1
1
1
1
0
1
F
D
1.51000
1
1
0
1
0
1
1
0
D
6
1.31500
1
1
1
1
1
1
1
0
F
E
1.51500
1
1
0
1
0
1
1
1
D
7
1.32000
1
1
1
1
1
1
1
1
F
F
1.52000
1
1
0
1
1
0
0
0
D
8
1.32500
1
1
0
1
1
0
0
1
D
9
1.33000
1
1
0
1
1
0
1
0
D
A
1.33500
1
1
0
1
1
0
1
1
D
B
1.34000
1
1
0
1
1
1
0
0
D
C
1.34500
1
1
0
1
1
1
0
1
D
D
1.35000
1
1
0
1
1
1
1
0
D
E
1.35500
1
1
0
1
1
1
1
1
D
F
1.36000
1
1
1
0
0
0
0
0
E
0
1.36500
1
1
1
0
0
0
0
1
E
1
1.37000
1
1
1
0
0
0
1
0
E
2
1.37500
1
1
1
0
0
0
1
1
E
3
1.38000
1
1
1
0
0
1
0
0
E
4
1.38500
1
1
1
0
0
1
0
1
E
5
1.39000
1
1
1
0
0
1
1
0
E
6
1.39500
1
1
1
0
0
1
1
1
E
7
1.40000
1
1
1
0
1
0
0
0
E
8
1.40500
7
6
5
4
3
2
1
0
1
1
0
0
0
0
0
1
C
1
1
0
0
0
0
1
0
C
1
1
0
0
0
0
1
1
C
1
1
0
0
0
1
0
0
1
1
0
0
0
1
0
1
1
0
0
0
1
1
1
0
0
0
1
1
0
0
1
1
0
1
1
0
1
1
1
16
HEX
VO (V)
As the load current increases from zero, the output voltage will
droop from the VID table value by an amount proportional to the
load current to achieve the load line. The ISL6363 can sense the
inductor current through the intrinsic DC Resistance (DCR) of the
inductors as shown in Figure 16 or through resistors in series
with the inductors as shown in Figure 22. In both methods,
capacitor Cn voltage represents the inductor total currents. A
droop amplifier converts Cn voltage into an internal current
source with the gain set by resistor Ri. The current source is used
for load line implementation, current monitor and overcurrent
protection.
Figure 9 shows the load line implementation. The ISL6363 drives
a current source Idroop out of the FB pin, described by Equation 1.
2xV Cn
I droop = ---------------Ri
(EQ. 1)
When using inductor DCR current sensing, a single NTC element
is used to compensate the positive temperature coefficient of the
copper winding, thus sustaining the load line accuracy with
reduced cost.
FN6898.0
September 29, 2011
ISL6363
eliminate the effect of phase node parasitic PCB DCR.
Equations 5 through 7 give the ISEN pin voltages:
Rdroop
VCCSENSE
Vdroop
FB
VR LOCAL VO
“CATCH”
RESISTOR
Idroop
E/A
COMP
Σ VDAC DAC VID
RTN
INTERNAL
TO IC
X1
V ISEN1 = ( R dcr1 + R pcb1 ) × I L1
(EQ. 5)
V ISEN2 = ( R dcr2 + R pcb2 ) × I L2
(EQ. 6)
V ISEN3 = ( R dcr3 + R pcb3 ) × I L3
(EQ. 7)
Where Rdcr1, Rdcr2 and Rdcr3 are inductor DCR; Rpcb1, Rpcb2
and Rpcb3 are parasitic PCB DCR between the inductor output
side pad and the output voltage rail; and IL1, IL2 and IL3 are
inductor average currents.
VSSSENSE
VSS
ISEN3
FIGURE 9. DIFFERENTIAL SENSING AND LOAD LINE
IMPLEMENTATION
V droop = R droop × I droop
INTERNAL
TO IC
ISEN2
Differential Voltage Sensing
Figure 9 also shows the differential voltage sensing scheme.
VCCSENSE and VSSSENSE are the remote voltage sensing signals
from the processor die. A unity gain differential amplifier senses
the VSSSENSE voltage and add it to the DAC output. The error
amplifier regulates the inverting and the non-inverting input
voltages to be equal as shown in Equation 3:
= V DAC + VSS SENSE
Equation 4 is the exact equation required for load line
implementation.
The VCCSENSE and VSSSENSE signals come from the processor die.
The feedback will be open circuit in the absence of the processor. As
Figure 9 shows, it is recommended to add a “catch” resistor to feed
the VR local output voltage back to the compensator, and add
another “catch” resistor to connect the VR local output ground to the
RTN pin. These resistors, typically 10Ω~100Ω, will provide voltage
feedback if the system is powered up without a processor installed.
Phase Current Balancing
The ISL6363 monitors individual phase average current by
monitoring the ISEN1, ISEN2, ISEN3, and ISEN4 voltages.
Figure 10 shows the current balancing circuit recommended for
ISL6363 for a 3-Phase configuration as an example. Each phase
node voltage is averaged by a low-pass filter consisting of Risen
and Cisen, and presented to the corresponding ISEN pin. Risen
should be routed to the inductor phase-node pad in order to
17
Rpcb2
Vo
IL2
Rdcr1
L1
Phase1
Risen
Rpcb1
IL1
FIGURE 10. CURRENT BALANCING CIRCUIT
The ISL6363 will adjust the phase pulse-width relative to the
other phases to make VISEN1 = VISEN2 = VISEN3, thus, to achieve
IL1 = IL2 = IL3, when there are Rdcr1 = Rdcr2 = Rdcr3 and
Rpcb1 = Rpcb2 = Rpcb3.
Using the same components for L1, L2 and L3 will provide a good
match of Rdcr1, Rdcr2 and Rdcr3. Board layout will determine
Rpcb1, Rpcb2 and Rpcb3. It is recommended to have symmetrical
layout for the power delivery path between each inductor and the
output voltage rail, such that Rpcb1 = Rpcb2 = Rpcb3.
ISEN3
Cisen
(EQ. 4)
Rdcr2
L2
Phase2
Risen
Cisen
(EQ. 3)
Rewriting Equation 3 and substitution of Equation 2 gives
VCC SENSE – VSS SENSE = V DAC – R droop × I droop
ISEN1
Rpcb3
IL3
Cisen
(EQ. 2)
Vdroop is the droop voltage required to implement load line.
Changing Rdroop or scaling Idroop can both change the load line
slope. Since Idroop also sets the overcurrent protection level, it is
recommended to first scale Idroop based on OCP requirement,
then select an appropriate Rdroop value to obtain the desired
load line slope.
droop
Phase3
Risen
Cisen
Idroop flows through resistor Rdroop and creates a voltage drop as
shown in Equation 2.
VCC SENSE + V
Rdcr3
L3
“CATCH”
RESISTOR
INTERNAL
TO IC
ISEN2
Cisen
Phase3
Risen
V3p
L3
Rdcr3
IL3
Risen
Rpcb3
V3n
Risen
V2p
Phase2
Risen
L2
Rdcr2
IL2
Risen
Rpcb2
Vo
V2n
Risen
ISEN1
Cisen
V1p
Phase1
Risen
Risen
L1
Rdcr1
IL1
Rpcb1
V1n
Risen
FIGURE 11. DIFFERENTIAL-SENSING CURRENT BALANCING CIRCUIT
Sometimes it is difficult to implement symmetrical layout. For
the circuit shown in Figure 10, asymmetric layout causes
different Rpcb1, Rpcb2 and Rpcb3, thus current imbalance.
Figure 11 shows a differential-sensing current balancing circuit
recommended for the ISL6363. The current sensing traces
should be routed to the inductor pads so they only pick up the
inductor DCR voltage. Each ISEN pin sees the average voltage of
FN6898.0
September 29, 2011
ISL6363
three sources: its own phase inductor phase-node pad, and the
other two phases inductor output side pads. Equations 8 thru 10
give the ISEN pin voltages:
V ISEN1 = V 1p + V 2n + V 3n
(EQ. 8)
V ISEN2 = V 1n + V 2p + V 3n
(EQ. 9)
V ISEN3 = V 1n + V 2n + V 3p
(EQ. 10)
REP RATE = 10kHz
The ISL6363 will make VISEN1 = VISEN2 = VISEN3 as shown in
Equations 11 and 12:
V 1p + V 2n + V 3n = V 1n + V 2p + V 3n
(EQ. 11)
V 1n + V 2p + V 3n = V 1n + V 2n + V 3p
(EQ. 12)
REP RATE = 25kHz
Rewriting Equation 11 gives Equation 13:
V 1p – V 1n = V 2p – V 2n
(EQ. 13)
and rewriting Equation 12 gives Equation 14:
V 2p – V 2n = V 3p – V 3n
(EQ. 14)
Combining Equations 13 and 14 gives:
V 1p – V 1n = V 2p – V 2n = V 3p – V 3n
(EQ. 15)
Therefore:
REP RATE = 50kHz
R dcr1 × I L1 = R dcr2 × I L2 = R dcr3 × I L3
(EQ. 16)
Current balancing (IL1 = IL2 = IL3) will be achieved when there is
Rdcr1 = Rdcr2 = Rdcr3. Rpcb1, Rpcb2 and Rpcb3 will not have any
effect.
Since the slave ripple capacitor voltages mimic the inductor
currents, the R3 modulator can naturally achieve excellent
current balancing during steady state and dynamic operations.
Figure 12 shows current balancing performance of the
evaluation board with a load transient of 12A/51A at different
rep rates. The inductor currents follow the load current dynamic
change with the output capacitors supplying the difference. The
inductor currents can track the load current well at low rep rate,
but cannot keep up when the rep rate gets into the hundred-kHz
range, where it’s out of the control loop bandwidth. The controller
achieves excellent current balancing in all cases installed.
REP RATE = 100kHz
CCM SWITCHING FREQUENCY
The Rfset resistor between the COMP and the VW pins sets the
VW windows size, therefore sets the switching frequency. When
the ISL6363 is in continuous conduction mode (CCM), the
switching frequency is not absolutely constant due to the nature
of the R3 modulator. As explained in the Multiphase R3
Modulator section on page 11, the effective switching frequency
will increase during load insertion and will decrease during load
release to achieve fast response. On the other hand, the
switching frequency is relatively constant at steady state.
Variation is expected when the power stage condition, such as
input voltage, output voltage, load, etc., changes. The variation is
usually less than 15% and doesn’t have any significant effect on
output voltage ripple magnitude. Equation 17 gives an estimate
of the frequency-setting resistor Rfset value. 8kΩ Rfset gives
approximately 300kHz switching frequency. Lower resistance
gives higher switching frequency.
R fset ( kΩ ) = ( Period ( μs ) – 0.29 ) × 2.65
18
(EQ. 17)
REP RATE = 200kHz
FIGURE 12. CURRENT BALANCING DURING DYNAMIC OPERATION.
CH1: IL1, CH2: ILOAD, CH3: IL2, CH4: IL3
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Modes of Operation
Table 3 shows VR2 operational modes, programmed by the PS
command. VR2 operates in 1-phase CCM in PS0 and PS1, and
enters 1-phase DE mode in PS2 and PS3 mode.
TABLE 2. VR1 MODES OF OPERATION
PWM4 PWM3
To Ext
Driver
To Ext
Driver
ISEN2
CONFIG.
To Power 4-phase
Stage
CPU VR
Config.
PS
MODE
OCP
THRESHOLD
(µA)
0
4-PH CCM
60
Dynamic Operation
1
2-PH CCM
30
2
1-PH DE
20
0
3-PH CCM
60
VR1 and VR2 behave the same during dynamic operation. The
controller responds to VID changes by slewing to the new voltage
at a slew rate indicated in the SetVID command. There are three
SetVID slew rates, namely SetVID_fast, SetVID_slow and
SetVID_decay.
1
2-PH CCM
40
2
1-PH DE
20
0
2-PH CCM
60
1
2-PH CCM
60
2
1-PH DE
30
1-PH CCM
60
3
Tie to
5V VCC
3-phase
CPU VR
Config.
3
Tie to
5V VCC
2-phase
CPU VR
Config.
3
Tie to 5V 1-phase
VCC
CPU VR
Config.
0
1
2
1-PH DE
VR1 can be configured for 4, 3, 2 or 1-phase operation. Table 2
shows VR1 configurations and operational modes, programmed
by the PWM4, PWM3 pins and the ISEN2 pin status, and the PS
command. For 3-phase configuration, tie the PWM4 pin to 5V. In
this configuration, phases 1, 2 and 3 are active. For 2-phase
configuration, tie the PWM4 and PWM3 pin to 5V. In this
configuration, phases 1 and 2 are active. For 1-phase
configuration, tie the PWM4, PWM3 and the ISEN2 pin to 5V. In
this configuration, only phase 1 is active.
In 4-phase configuration, VR1 operates in 4-phase CCM in PS0
mode. It enters 2-phase CCM operation in PS1 mode. It enters
1-phase DE operation in PS2 and PS3 modes.
In 3-phase configuration, VR1 operates in 3-phase CCM in PS0
mode. It enters 2-phase CCM operation in PS1 mode. It enters
1-phase DE operation in PS2 and PS3 modes.
In 2-phase configuration, VR1 operates in 2-phase CCM in PS0
and PS1 mode. It enters 1-phase DE mode in PS2 and PS3
modes.
In 1-phase configuration, VR1 operates in 1-phase CCM in PS0
and PS1, and enters 1-phase DE mode in PS2 and PS3.
TABLE 3. VR2 MODES OF OPERATION
0
MODE
1-phase CCM
2
OCP THRESHOLD
60µA
1
SetVID_fast command prompts the controller to enter CCM and
to actively drive the output voltage to the new VID value at a
minimum 10mV/µs slew rate.
SetVID_slow command prompts the controller to enter CCM and
to actively drive the output voltage to the new VID value at a
minimum 2.5mV/µs slew rate.
SetVID_decay command prompts the controller to enter DE
mode. The output voltage will decay down to the new VID value at
a slew rate determined by the load. If the voltage decay rate is
too fast, the controller will limit the voltage slew rate at
SetVID_slow slew rate.
ALERT# will be asserted low at the end of SetVID_fast and
SetVID_slow VID transitions.
3
PS
VR2 can be disabled completely by tying ISUMNG to 5V, and all
communication to VR2 will be blocked.
S e tV ID _ d e c a y
S e tV ID _ fa s t/s lo w
VO
V ID
t3
t1
ALERT#
T _ a le rt
t2
FIGURE 13. SETVID DECAY PRE-EMPTIVE BEHAVIOR
Figure 13 shows SetVID Decay Pre-Emptive behavior. The
controller receives a SetVID_decay command at t1. The VR
enters DE mode and the output voltage VO decays down slowly.
At t2, before VO reaches the intended VID target of the
SetVID_decay command, the controller receives a SetVID_fast (or
SetVID_slow) command to go to a voltage higher than the actual
VO. The controller will turn around immediately and slew VO to
the new target voltage at the slew rate specified by the SetVID
command. At t3, VO reaches the new target voltage and the
controller asserts the ALERT# signal.
The R3 modulator intrinsically has voltage feed-forward. The
output voltage is insensitive to a fast slew rate input voltage
change.
1-phase DE
3
19
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ISL6363
VR_HOT#/ALERT# Behavior
VR Temperature
7
Temp Zone
Bit 7 =1
1
Bit 6 =1
5. The CPU reads Status_1 register value to know that the alert
assertion is due to TZONE register bit 6 flipping.
3% Hysteresis
1111 1111
10
0111 1111
0011 1111
Bit 5 =1
12
Temp Zone
Register
2
0001 1111 0011 1111
Status 1
Register = “001”
8
0111 1111
3
= “011”
5
1111 1111
0111 1111
0011 1111
13
GerReg
Status1
SVID
ALERT#
4
VR_HOT#
0001 1111
6
0001 1111
= “001”
GerReg
Status1
14
9
15
FIGURE 14. VR_HOT#/ALERT# BEHAVIOR
8. The temperature crosses the threshold where the TZONE
register Bit 7 changes from 0 to 1.
9. The controller asserts the VR_HOT# signal. The CPU throttles
back and the system temperature starts dropping eventually.
10. The temperature crosses the threshold where the TZONE
register bit 6 changes from 1 to 0. This threshold is 1 ADC step
lower than the one when VR_HOT# gets asserted, to provide
3% hysteresis.
12. The temperature crosses the threshold where the TZONE
register bit 5 changes from 1 to 0. This threshold is 1 ADC step
lower than the one when ALERT# gets asserted during the
temperature rise to provide 3% hysteresis.
13. The controller changes Status_1 register bit 1 from 1 to 0.
The controller drives 60µA current source out of the NTC pin and
the NTCG pin alternatively at 1kHz frequency with 50% duty
cycle. The current source flows through the respective NTC
resistor networks on the pins and creates voltages that are
monitored by the controller through an A/D converter (ADC) to
generate the TZONE value. Table 4 shows the programming table
for TZONE. The user needs to scale the NTC and the NTCG
network resistance such that it generates the NTC (and NTCG) pin
voltage that corresponds to the left-most column. Do not use any
capacitor to filter the voltage.
TABLE 4. TZONE TABLE
VNTC (V)
TMAX (%)
TZONE
0.84
>100
FFh
0.88
100
FFh
0.92
97
7Fh
0.96
94
3Fh
1.00
91
1Fh
1.04
88
0Fh
1.08
85
07h
1.12
82
03h
1.16
79
01h
1.2
76
01h
>1.2
<76
00h
Figure 14 shows how the NTC and the NTCG network should be
designed to get correct VR_HOT#/ALERT# behavior when the
system temperature rises and falls, manifested as the NTC and the
NTCG pin voltage falls and rises. The series of events are:
1. The temperature rises so the NTC pin (or the NTCG pin)
voltage drops. TZONE value changes accordingly.
2. The temperature crosses the threshold where the TZONE
register Bit 6 changes from 0 to 1.
3. The controller changes Status_1 register bit 1 from 0 to 1.
20
7. The temperature continues rising.
11. The controllers de-assert the VR_HOT# signal.
16
11
4. The controller asserts ALERT#.
6. The controller clears ALERT#.
14. The controller asserts ALERT#.
15. The CPU reads Status_1 register value to know that the alert
assertion is due to TZONE register bit 5 flipping.
16. The controller clears ALERT#.
Protection Functions
VR1 and VR2 both provide overcurrent, current-balance and
overvoltage fault protections. The controller also provides
over-temperature protection. The following discussion is based on
VR1 and also applies to VR2.
The controller determines overcurrent protection (OCP) by
comparing the average value of the droop current Idroop with an
internal current source threshold as Table 2 shows. It declares
OCP when Idroop is above the threshold for 120µs.
For overcurrent conditions above 1.5x the OCP level, the PWM
outputs will immediately shut off and PGOOD will go low to
maximize protection. This protection is also referred to as
way-overcurrent protection or fast-overcurrent protection, for
short-circuit protections.
The controller monitors the ISEN pin voltages to determine
current-balance protection. If the ISEN pin voltage difference is
greater than 9mV for 1ms, the controller will declare a fault and
latch off.
The controller takes the same actions for all of the above fault
protections: de-assertion of PGOOD and turn-off of the high-side
and low-side power MOSFETs. Any residual inductor current will
decay through the MOSFET body diodes.
The controller will declare an overvoltage fault and de-assert PGOOD
if the output voltage exceeds the VID set value by +200mV. The
ISL6363 will immediately declare an OV fault, de-assert PGOOD,
and turn on the low-side power MOSFETs. The low-side power
MOSFETs remain on until the output voltage is pulled down below
the VID set value when all power MOSFETs are turned off. If the
output voltage rises above the VID set value +200mV again, the
protection process is repeated. This behavior provides the
maximum amount of protection against shorted high-side power
MOSFETs while preventing output ringing below ground.
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September 29, 2011
ISL6363
All the above fault conditions can be reset by bringing VR_ON low
or by bringing VCC below the POR threshold. When VR_ON and
VCC return to their high operating levels, a soft-start will occur
TABLE 5. FAULT PROTECTION SUMMARY
FAULT TYPE
Overcurrent
Phase Current
Unbalance
Way-Overcurrent
(1.5xOC)
120µs
PROTECTION ACTION
FAULT
RESET
Immediately
Overvoltage
+200mV
C3.1
C2 R3
FB
E/A
C2.2 R3.2
PWM tri-state, PGOOD VR_ON
latched low
toggle or
VCC toggle
1ms
C3.1
R1
VSEN
C1 R2
CONTROLLER IN
PS2/3 MODE
C2 R3
Table 5 summarizes the fault protections.
FAULT DURATION
BEFORE
PROTECTION
C1 R2
CONTROLLER IN
PS0/1 MODE
VSEN
COMP
FB
R1
E/A
C2.2 R3.2
PSICOMP
COMP
PSICOMP
FIGURE 15. PSICOMP FUNCTION
When the PSICOMP switch is off, C2.2 and R3.2 are
disconnected from the FB pin. However, the controller still
actively drives the PSICOMP pin to allow for smooth transitions
between modes of operation.
The PSICOMP function ensures excellent transient response in
both PS0, PS1 and PS2/3 modes of operation. If the PSICOMP
function is not needed C2.2 and R3.2 can be disconnected.
PGOOD latched low.
Actively pulls the
output voltage to
below VID value, then
tri-state.
Adaptive Body Diode Conduction Time
Reduction
CURRENT MONITOR
The IMON pin voltage range is 0V to 2.7V. The controller monitors
the IMON pin voltage and considers that VR1 has reached
ICCMAX on IMON pin voltage is 2.7V.
In DCM, the controller turns off the low-side MOSFET when the
inductor current approaches zero. During on-time of the low-side
MOSFET, phase voltage is negative and the amount is the
MOSFET rDS(ON) voltage drop, which is proportional to the
inductor current. A phase comparator inside the controller
monitors the phase voltage during on-time of the low-side
MOSFET and compares it with a threshold to determine the
zero-crossing point of the inductor current. If the inductor current
has not reached zero when the low-side MOSFET turns off, it will
flow through the low-side MOSFET body diode, causing the phase
node to have a larger voltage drop until it decays to zero. If the
inductor current has crossed zero and reversed the direction when
the low-side MOSFET turns off, it will flow through the high-side
MOSFET body diode, causing the phase node to have a spike until
it decays to zero. The controller continues monitoring the phase
voltage after turning off the low-side MOSFET and adjusts the
phase comparator threshold voltage accordingly in iterative steps,
such that the low-side MOSFET body diode conducts for
approximately 40ns to minimize the body diode-related loss.
PSICOMP Function
Supported Data and Configuration Registers
Figure 15 shows the PSICOMP function. A switch turns on to
short the FB and the PSICOMP pins when the controller is in PS2
mode. The RC network C2.2 and R3.2 is connected in parallel
with R1 and C2/R3 compensation network in PS2/3 mode. This
additional RC network increases the high frequency content of
the signal passing from the output voltage to the COMP pin which
will improve transient response in PS2/3 mode of operation.
The controller supports the following data and configuration
registers.
The ISL6363 provides the current monitor function for both VRs.
IMON pin reports VR1 inductor current and IMONG pins reports
VR2 inductor current. Since they are designed following the same
principle, the following discussion will be only based on the IMON
pin but also applies to the IMONG pin.
The IMON pin outputs a high-speed analog current source that is
3 times of the droop current flowing out of the FB pin. Thus
becoming Equation 18:
I IMON = 3 × I droop
(EQ. 18)
As the “Simplified Application Circuit” on page 6 shows, a
resistor Rimon is connected to the IMON pin to convert the IMON
pin current to voltage. A capacitor can be paralleled with Rimon
to filter the voltage information.
21
TABLE 6. SUPPORTED DATA AND CONFIGURATION
REGISTERS
INDEX
REGISTER
NAME
DEFAULT
VALUE
DESCRIPTION
00h
Vendor ID
Uniquely identifies the VR
vendor. Assigned by Intel.
12h
01h
Product ID
Uniquely identifies the VR
product. Intersil assigns this
number.
1Fh
02h
Product
Revision
Uniquely identifies the revision
of the VR control IC. Intersil
assigns this data.
05h
Protocol ID
Identifies what revision of SVID 01h
protocol the controller supports.
FN6898.0
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ISL6363
TABLE 6. SUPPORTED DATA AND CONFIGURATION
REGISTERS (Continued)
TABLE 6. SUPPORTED DATA AND CONFIGURATION
REGISTERS (Continued)
INDEX
REGISTER
NAME
DESCRIPTION
DEFAULT
VALUE
06h
Capability
81h
Identifies the SVID VR
capabilities and which of the
optional telemetry registers are
supported.
10h
Status_1
Data register read after ALERT# 00h
signal. Indicating if a VR rail has
settled, has reached VRHOT
condition or has reached ICC
max.
11h
Status_2
Data register showing status_2 00h
communication.
12h
Temperature
Zone
Data register showing
temperature zones that have
been entered.
1Ch
Status_2_
LastRead
This register contains a copy of 00h
the Status_2 data that was last
read with the GetReg (Status_2)
command.
21h
ICC max
Data register containing the ICC Refer to
max the platform supports, set Table 7
at start-up by resistors Rprog1
and Rprog2. The platform
design engineer programs this
value during the design process.
Binary format in amps, i.e.,
100A = 64h
22h
24h
25h
Temp max
SR-fast
SR-slow
26h
VBOOT
If programmed by the platform, 00h
the VR supports VBOOT voltage
during start-up ramp. The VR will
ramp to VBOOT and hold at
VBOOT until it receives a new
SetVID command to move to a
different voltage.
30h
Vout max
This register is programmed by FBh
the master and sets the
maximum VID the VR will
support. If a higher VID code is
received, the VR will respond
with “not supported”
acknowledge.
DEFAULT
VALUE
DESCRIPTION
00h
VID Setting
Data register containing
currently programmed VID
voltage. VID data format.
32h
Power State
Register containing the current 00h
programmed power state.
33h
Voltage Offset Sets offset in VID steps added to 00h
the VID setting for voltage
margining. Bit 7 is a sign bit,
0 = positive margin,
1 = negative margin. Remaining
7 bits are # VID steps for the
margin.
00h = no margin,
01h = +1 VID step
02h = +2 VID steps
34h
Multi VR Config Data register that configures
multiple VRs behavior on the
same SVID bus.
VR1: 00h
VR2: 01h
Key Component Selection
Inductor DCR Current-Sensing Network
Phase1
Phase2
Phase3
Rsum
Rsum
ISUM+
Rsum
L
L
L
Rntcs
Rp
DCR
DCR
DCR
Cn Vcn
Rntc
Ro
0Ah
Is 4x slower than normal. Binary 02h
format in mV/µs. i.e.,
02h = 2.5mV/µs
22
REGISTER
NAME
31h
00h
Refer to
Data register containing the
temperature max the platform Table 8
support, set at startup by
resistor Rprog2. The platform
design engineer programs this
value during the design process.
Binary format in °C, i.e.,
+100°C = 64h
Slew Rate Normal. The fastest
slew rate the platform VR can
sustain. Binary format in
mV/µs. i.e., 0Ah = 10mV/µs.
INDEX
Ri
ISUM-
Ro
Ro
Io
FIGURE 16. DCR CURRENT-SENSING NETWORK
Figure 16 shows the inductor DCR current-sensing network for a
3-phase solution. An inductor current flows through the DCR and
creates a voltage drop. Each inductor has two resistors in Rsum
and Ro connected to the pads to accurately sense the inductor
current by sensing the DCR voltage drop. The Rsum and Ro
resistors are connected in a summing network as shown, and feed
the total current information to the NTC network (consisting of
Rntcs, Rntc and Rp) and capacitor Cn. Rntc is a negative
temperature coefficient (NTC) thermistor, used to
temperature-compensate the inductor DCR change.
The inductor output side pads are electrically shorted in the
schematic, but have some parasitic impedance in actual board
layout, which is why one cannot simply short them together for the
FN6898.0
September 29, 2011
ISL6363
current-sensing summing network. It is recommended to use
1Ω~10Ω Ro to create quality signals. Since Ro value is much
smaller than the rest of the current sensing circuit, the following
analysis will ignore it for simplicity.
The summed inductor current information is presented to the
capacitor Cn. Equations 19 thru 23 describe the
frequency-domain relationship between inductor total current
Io(s) and Cn voltage VCn(s):
⎛
⎞
R ntcnet
⎜
DCR⎟
V Cn ( s ) = ⎜ ----------------------------------------- × ------------⎟ × I o ( s ) × A cs ( s )
R sum
N ⎟
⎜
⎝ R ntcnet + ------------⎠
N
(EQ. 19)
( R ntcs + R ntc ) × R p
R ntcnet = --------------------------------------------------R ntcs + R ntc + R p
(EQ. 20)
s
1 + -----ωL
A cs ( s ) = ---------------------s
1 + -----------ω sns
(EQ. 21)
DCR
ω L = -----------L
(EQ. 22)
1
ω sns = -----------------------------------------------------R sum
R ntcnet × -------------N
----------------------------------------- × C n
R sum
R ntcnet + -------------N
(EQ. 23)
Acs(s) is unity gain at all frequencies. By forcing wL equal to wsns
and solving for the solution, Equation 24 gives Cn value.
L
C n = -----------------------------------------------------------R sum
R ntcnet × -------------N
----------------------------------------- × DCR
R sum
R ntcnet + -------------N
(EQ. 24)
For example, given N = 3, Rsum = 3.65kΩ, Rp = 11kΩ,
Rntcs = 2.61kΩ, Rntc = 10kΩ, DCR = 0.88mΩ and L = 0.36µH,
Equation 24 gives Cn = 0.406µF.
Assuming the compensator design is correct, Figure 17 shows the
expected load transient response waveforms if Cn is correctly
selected. When the load current Icore has a square change, the
output voltage VCORE also has a square response.
If Cn value is too large or too small, VCn(s) will not accurately
represent real-time Io(s) and will worsen the transient response.
Figure 18 shows the load transient response when Cn is too
small. VCORE will sag excessively upon load insertion and may
create a system failure. Figure 19 shows the transient response
when Cn is too large. VCORE is sluggish in drooping to its final
value. There will be excessive overshoot if load insertion occurs
during this time, which may potentially hurt the CPU reliability.
IO
Where N is the number of phases.
Transfer function Acs(s) always has unity gain at DC. The inductor
DCR value increases as the winding temperature increases,
giving higher reading of the inductor DC current. The NTC Rntc
values decreases as its temperature decreases. Proper
selections of Rsum, Rntcs, Rp and Rntc parameters ensure that
VCn represent the inductor total DC current over the temperature
range of interest.
There are many sets of parameters that can properly
temperature-compensate the DCR change. Since the NTC network
and the Rsum resistors form a voltage divider, Vcn is always a
fraction of the inductor DCR voltage. It is recommended to have a
higher ratio of Vcn to the inductor DCR voltage, so the droop circuit
has higher signal level to work with.
A typical set of parameters that provide good temperature
compensation are: Rsum = 3.65kΩ, Rp = 11kΩ, Rntcs = 2.61kΩ and
Rntc = 10kΩ (ERT-J1VR103J). The NTC network parameters may
need to be fine tuned on actual boards. One can apply full load DC
current and record the output voltage reading immediately; then
record the output voltage reading again when the board has
reached the thermal steady state. A good NTC network can limit the
output voltage drift to within 2mV. It is recommended to follow the
Intersil evaluation board layout and current-sensing network
parameters to minimize engineering time.
VCn(s) also needs to represent real-time Io(s) for the controller to
achieve good transient response. Transfer function Acs(s) has a
pole wsns and a zero wL. One needs to match wL and wsns so
23
VO
FIGURE 17. DESIRED LOAD TRANSIENT RESPONSE WAVEFORMS
IO
VO
FIGURE 18. LOAD TRANSIENT RESPONSE WHEN Cn IS TOO SMALL
IO
VO
FIGURE 19. LOAD TRANSIENT RESPONSE WHEN Cn IS TOO LARGE
FN6898.0
September 29, 2011
ISL6363
IO
IL
VO
RING
BACK
FIGURE 20. OUTPUT VOLTAGE RING BACK PROBLEM
ISUM+
Rip and Cip form an R-C branch in parallel with Ri, providing a
lower impedance path than Ri at the beginning of io change. Rip
and Cip do not have any effect at steady state. Through proper
selection of Rip and Cip values, idroop can resemble io rather than
iL, and VO will not ring back. The recommended value for Rip is
100Ω. Cip should be determined through tuning the load
transient response waveforms on an actual board. The
recommended range for Cip is 100pF~2000pF. However, it
should be noted that the Rip -Cip branch may distort the idroop
waveform. Instead of being triangular as the real inductor
current, idroop may have sharp spikes, which may adversely
affect idroop average value detection and therefore may affect
OCP accuracy. User discretion is advised.
Resistor Current-Sensing Network
Rntcs
Cn.1
Phase2
Phase3
L
L
L
DCR
DCR
DCR
Cn.2 Vcn
Rp
Rntc
Phase1
Rn
OPTIONAL
ISUM-
Ri
Rsum
Rip
Rsum
Cip
OPTIONAL
Rsen
Rsen
Rsen
Vcn
Ro
FIGURE 21. OPTIONAL CIRCUITS FOR RING BACK REDUCTION
Figure 20 shows the output voltage ring back problem during
load transient response. The load current io has a fast step
change, but the inductor current IL cannot accurately follow.
Instead, IL responds in first order system fashion due to the
nature of current loop. The ESR and ESL effect of the output
capacitors makes the output voltage VO dip quickly upon load
current change. However, the controller regulates VO according to
the droop current Idroop, which is a real-time representation of IL;
therefore it pulls VO back to the level dictated by IL, causing the
ring back problem. This phenomenon is not observed when the
output capacitor have very low ESR and ESL, such as all ceramic
capacitors.
Figure 21 shows two optional circuits for reduction of the ring
back.
Cn is the capacitor used to match the inductor time constant. It
usually takes the parallel of two (or more) capacitors to get the
desired value. Figure 21 shows that two capacitors Cn.1 and Cn.2
are in parallel. Resistor Rn is an optional component to reduce
the VO ring back. At steady state, Cn.1 + Cn.2 provides the desired
Cn capacitance. At the beginning of io change, the effective
capacitance is less because Rn increases the impedance of the
Cn.1 branch. As Figure 18 explains, VO tends to dip when Cn is too
small, and this effect will reduce the VO ring back. This effect is
more pronounced when Cn.1 is much larger than Cn.2. It is also
more pronounced when Rn is bigger. However, the presence of
Rn increases the ripple of the Vn signal if Cn.2 is too small. It is
recommended to keep Cn.2 greater than 2200pF. Rn value
usually is a few ohms. Cn.1, Cn.2 and Rn values should be
determined through tuning the load transient response
waveforms on an actual board.
24
ISUM+
Rsum
Cn
Ri
ISUM-
Ro
Ro
Io
FIGURE 22. RESISTOR CURRENT-SENSING NETWORK
Figure 22 shows the resistor current-sensing network for a
2-phase solution. Each inductor has a series current-sensing
resistor Rsen. Rsum and Ro are connected to the Rsen pads to
accurately capture the inductor current information. The Rsum
and Ro resistors are connected to capacitor Cn. Rsum and Cn
form a filter for noise attenuation. Equations 25 thru 27 give
VCn(s) expression
R sen
V Cn ( s ) = ------------ × I o ( s ) × A Rsen ( s )
N
1
A Rsen ( s ) = ---------------------s
1 + -----------ω sns
1
ω Rsen = --------------------------R sum
-------------- × C n
N
(EQ. 25)
(EQ. 26)
(EQ. 27)
Transfer function ARsen(s) always has unity gain at DC.
Current-sensing resistor Rsen value will not have significant
variation over-temperature, so there is no need for the NTC
network.
The recommended values are Rsum = 1kΩ and Cn = 5600pF.
FN6898.0
September 29, 2011
ISL6363
Overcurrent Protection
LOAD LINE SLOPE
Refer to Equation 1 on page 16 and Figures 16, 20 and 22;
resistor Ri sets the droop current Idroop. Tables 2 (page 19)
and 3 (page 19) show the internal OCP threshold. It is
recommended to design Idroop without using the Rcomp resistor.
Refer to Figure 9.
For example, the OCP threshold is 60µA for 3-phase solution. We
will design Idroop to be 40.9µA at full load, so the OCP trip level is
1.5x of the full load current.
For inductor DCR sensing, Equation 28 gives the DC relationship
of Vcn(s) and Io(s).
⎛
⎞
R ntcnet
⎜
DCR⎟
-------------------------------------------------V Cn = ⎜
×
⎟ ×I
N ⎟ o
R sum
⎜
⎝ R ntcnet + ------------⎠
N
(EQ. 28)
Substitution of Equation 28 into Equation 1 gives Equation 29:
R ntcnet
DCR
2
I droop = ----- × ----------------------------------------- × ------------ × I o
N
R sum
Ri
R ntcnet + -------------N
(EQ. 29)
Therefore:
2R ntcnet × DCR × I o
R i = -------------------------------------------------------------------------------R sum
N × ⎛ R ntcnet + --------------⎞ × I droop
⎝
N ⎠
(EQ. 30)
Substitution of Equation 20 and application of the OCP condition
in Equation 30 gives Equation 31:
( R ntcs + R ntc ) × R p
2 × --------------------------------------------------- × DCR × I omax
R ntcs + R ntc + R p
R i = ------------------------------------------------------------------------------------------------------------------------(
R
⎛ ntcs + R ntc ) × R p R sum⎞
N × ⎜ --------------------------------------------------- + --------------⎟ × I droopmax
N ⎠
⎝ R ntcs + R ntc + R p
(EQ. 31)
Where Iomax is the full load current, Idroopmax is the
corresponding droop current. For example, given N = 3,
Rsum = 3.65kΩ, Rp = 11kΩ, Rntcs = 2.61kΩ, Rntc = 10kΩ,
DCR = 0.88mΩ, Iomax = 51A and Idroopmax = 40.9µA,
Equation 31 gives Ri = 606Ω.
For inductor DCR sensing, substitution of Equation 29 into
Equation 2 gives the load line slope expression:
2R droop
R ntcnet
V droop
DCR
LL = ------------------ = ---------------------- × ----------------------------------------- × -----------N
Io
Ri
R sum
R ntcnet + -------------N
For resistor sensing, substitution of Equation 33 into Equation 2
gives the load line slope expression:
2R sen × R droop
V droop
LL = ------------------ = ----------------------------------------N × Ri
Io
(EQ. 37)
Substitution of Equation 30 and rewriting Equation 36, or
substitution of Equation 34 and rewriting Equation 37 give the
same result in Equation 38:
Io
R droop = ---------------- × LL
I droop
(EQ. 38)
One can use the full load condition to calculate Rdroop. For
example, given Iomax = 51A, Idroopmax = 40.9µA and
LL = 1.9mΩ, Equation 38 gives Rdroop = 2.37kΩ.
It is recommended to start with the Rdroop value calculated by
Equation 38, and fine tune it on the actual board to get accurate
load line slope. One should record the output voltage readings at
no load and at full load for load line slope calculation. Reading
the output voltage at lighter load instead of full load will increase
the measurement error.
Compensator
Figure 17 shows the desired load transient response waveforms.
Figure 23 shows the equivalent circuit of a voltage regulator (VR)
with the droop function. A VR is equivalent to a voltage source
(= VID) and output impedance Zout(s). If Zout(s) is equal to the
load line slope LL, i.e., constant output impedance, in the entire
frequency range, VO will have square response when Io has a
square change.
For resistor sensing, Equation 32 gives the DC relationship of
Vcn(s) and Io(s).
R sen
V Cn = ------------ × I o
N
(EQ. 36)
Zout(s) = LL
IO
(EQ. 32)
VID
VR
LOAD
VO
Substitution of Equation 32 into Equation 1 gives Equation 33:
2 R sen
I droop = ----- × ------------ × I o
N
Ri
(EQ. 33)
FIGURE 23. VOLTAGE REGULATOR EQUIVALENT CIRCUIT
Therefore
2R sen × I o
R i = --------------------------N × I droop
(EQ. 34)
Substitution of Equation 34 and application of the OCP condition
in Equation 30 gives Equation 35:
2R sen × I omax
R i = -------------------------------------N × I droopmax
(EQ. 35)
Where Iomax is the full load current, Idroopmax is the corresponding
droop current. For example, given N = 3, Rsen = 1mΩ, Iomax = 53A
and Idroopmax = 40.9µA, Equation 35 gives Ri = 863Ω.
25
Intersil provides a Microsoft Excel-based spreadsheet to help
design the compensator and the current sensing network, so the
VR achieves constant output impedance as a stable system.
Figure 26 shows a screenshot of the spreadsheet.
A VR with an active droop function is a dual-loop system consisting
of a voltage loop and a droop loop which is a current loop.
However, neither loop alone is sufficient to describe the entire
system. The spreadsheet shows two loop gain transfer functions,
T1(s) and T2(s), that describe the entire system. Figure 24
conceptually shows T1(s) measurement set-up and Figure 25
FN6898.0
September 29, 2011
ISL6363
conceptually shows T2(s) measurement set-up. The VR senses the
inductor current, multiplies it by a gain of the load line slope, then
adds it on top of the sensed output voltage and feeds it to the
compensator. T(1) is measured after the summing node, and T2(s)
is measured in the voltage loop before the summing node. The
spreadsheet gives both T1(s) and T2(s) plots. However, only T2(s)
can be actually measured on an ISL6363 regulator.
T1(s) is the total loop gain of the voltage loop and the droop loop.
It always has a higher crossover frequency than T2(s) and has
more meaning of system stability.
T2(s) is the voltage loop gain with closed droop loop. It has more
meaning of output voltage response.
Design the compensator to get stable T1(s) and T2(s) with
sufficient phase margin, and output impedance equal or smaller
than the load line slope.
VO
L
Q1
VIN
VO
L
Q1
GATE Q2
DRIVER
IO
Cout
VIN
GATE Q2
DRIVER
LOAD LINE SLOPE
COUT
LOAD LINE SLOPE
20
20
EA
MOD.
COMP
EA
MOD.
VID
CHANNEL B
LOOP GAIN =
CHANNEL A
ISOLATION
TRANSFORMER
CHANNEL A
CHANNEL B
NETWORK
ANALYZER EXCITATION OUTPUT
FIGURE 24. LOOP GAIN T1(s) MEASUREMENT SET-UP
26
IO
COMP
CHANNEL B
LOOP GAIN =
CHANNEL A
VID
ISOLATION
TRANSFORMER
CHANNEL A
CHANNEL B
NETWORK
ANALYZER EXCITATION OUTPUT
FIGURE 25. LOOP GAIN T2(s) MEASUREMENT SET-UP
FN6898.0
September 29, 2011
27
ISL6363
FN6898.0
September 29, 2011
FIGURE 26. SCREENSHOT OF THE COMPENSATOR DESIGN SPREADSHEET
ISL6363
Programming Resistors
There are three programming resistors: Rprog1, Rprog2 and
Raddr. Table 7 shows how to select Rprog1 based on VBOOT and
IMAX_CR register settings. VR1 can power to 0V VBOOT or an
internally-set VBOOT based on Rprog1 value. When the controller
works with an actual CPU, select Rprog1 such that VR1 powers up
to VBOOT = 0V as required by the SVID command. In the absence
of a CPU, such as testing of the only the VR, select Rprog1 such
that VR1 powers up to the internally-set VBOOT, which by default
is 1.1V. Determine the maximum current VR1 can support and
set the IMAX_CR register value accordingly by selecting the
appropriate Rprog1 value. The CPU will read the IMAX_CR register
and ensures that the CPU CORE current doesn’t exceed the value
specified by IMAX_CR.
Table 8 shows how to select Rprog2 based on TMAX and
IMAX_GR register settings. There are four TMAX temperatures to
choose from: +120°C, +110°C, +105°C, and +95°C. There are
also four IMAX_GR values to choose from: 35A, 30A, 25A and
20A.
TABLE 7. RPROG1 PROGRAMMING TABLE
IMAX
IMAX
IMAX
IMAX
CORE
CORE
CORE
CORE
Nph = 4 (A) Nph = 3 (A) Nph = 2 (A) Nph = 1 (A)
TABLE 8. RPROG2 PROGRAMMING TABLE
RPROG2 (kΩ)
TMAX (°C)
IMAX_GR (A)
7.15
120
30
13.0
120
25
20.5
120
20
27.4
110
20
38.3
110
25
52.3
110
30
66.5
110
35
80.6
105
35
95.3
105
30
113
105
25
137
105
20
165
95
20
196
95
25
226
95
30
Open Circuit
95
35
RPROG1
(kΩ)
BOOT
(V)
7.15
1.1
100
75
50
25
13.0
1.1
108
81
54
27
20.5
1.1
116
87
58
29
27.4
1.1
124
93
62
31
38.3
1.1
132
99
66
33
52.3
1.1
140
105
70
35
66.5
1.1
148
111
74
37
RADDR
(kΩ)
VR1 AND VR1 SVID ADDRESS
80.6
0
148
111
74
37
0
0,1
95.3
0
140
105
70
35
7.15
0,1
113
0
132
99
66
33
13
2,3
137
0
124
93
62
31
20.5
2,3
165
0
116
87
58
29
27.4
4,5
196
0
108
81
54
27
38.3
4,5
226
0
100
75
50
25
52.3
6,7
Open
Circuit
0
92
69
46
23
66.5
6,7
80.6
8,9
95.3
8,9
113
A,B
137
A,B
165
C,D
196
C,D
226
0,1
Open Circuit
0,1
28
Table 9 shows how to select Rprog2 based on TMAX and
IMAX_GR register settings. There are four TMAX temperatures to
choose from: +120°C, +110°C, +105°C, and +95°C. There are
also four IMAX_GR values to choose from: 35A, 30A, 25A and
20A.
TABLE 9. RADDR PROGRAMMING TABLE
FN6898.0
September 29, 2011
ISL6363
NTC Network on the NTC and the NTCG pins
The controller drives 60µA current source out of the NTC pin and
the NTCG pin alternatively at 1kHz frequency with 50% duty
cycle. The current source flows through the respective NTC
resistor networks on the pins and creates voltages that are
monitored by the controller through an A/D converter to generate
the TZONE value. Table 10 shows the programming table for
TZONE. The user needs to scale the NTC (and NTCG) network
resistance such that it generates the NTC (and NTCG) pin voltage
that corresponds to the left-most column. Do not use any
capacitor to filter the voltage. On ADC Output = 7, the controller
issues thermal alert to the CPU, on ADC Output <7, the controller
asserts the VR_HOT# signal.
TABLE 10. TZONE PROGRAMMING TABLE
VNTC (V)
ADC OUTPUT
%TMAX
TZONE
0.64
0
>100%
FFh
0.68
1
>100%
FFh
0.72
2
>100%
FFh
0.76
3
>100%
FFh
0.80
4
>100%
FFh
0.84
5
>100%
FFh
0.88
6
100%
FFh
0.92
7
97%
7Fh
0.96
8
94%
3Fh
1.00
9
91%
1Fh
1.04
A
88%
0Fh
1.08
B
85%
07h
1.12
C
82%
03h
1.16
D
79%
01h
1.2
E
76%
01h
>1.2
F
<76%
00h
For example, given LL = 1.9mΩ, Rdroop = 2.825kΩ,
VRimon = 2.7V at Iomax = 53A, Equation 42 gives
Rimon = 25.2kΩ.
A capacitor Cimon can be paralleled with Rimon to filter the IMON
pin voltage. The RimonCimon time constant is the user’s choice. It
is recommended to have a time constant long enough such that
switching frequency ripples are removed.
Current Balancing
The ISL6363 achieves current balancing through matching the
ISEN pin voltages. Risen and Cisen form filters to remove the
switching ripple of the phase node voltages. It is recommended
to use a rather long RisenCisen time constant such that the ISEN
voltages have minimal ripple and represent the DC current
flowing through the inductors. Recommended values are
Rs = 10kΩ and Cs = 0.22µF.
Optional Slew Rate Compensation Circuit for
1-Tick VID Transition
Rdroop
Vcore
Rvid Cvid
OPTIONAL
FB
Ivid
Idroop_vid
COMP
E/A
Σ VDACDAC
VIDs
RTN
INTERNAL
TO IC
X1
VID<0:6>
VSSSENSE
VSS
VID<0:6>
Current Monitor
Refer to Equation 18 for the IMON pin current expression.
Vfb
Referencing the “Simplified Application Circuit” on page 6, the
IMON pin current flows through Rimon. The voltage across Rimon is
expressed in Equation 39:
Ivid
V Rimon = 3 × I droop × R imon
(EQ. 39)
Vcore
Rewriting Equation 38 gives Equation 40:
Io
I droop = ------------------ × LL
R droop
(EQ. 40)
Idroop_vid
Substitution of Equation 40 into Equation 39 gives Equation 41:
3I o × LL
V Rimon = --------------------- × R imon
R droop
(EQ. 41)
Rewriting Equation 41 and application of full load condition gives
Equation 42:
V Rimon × R droop
R imon = -------------------------------------------3I o × LL
(EQ. 42)
29
FIGURE 27. OPTIONAL SLEW RATE COMPENSATION CIRCUIT FOR
1-TICK VID TRANSITION
During a large VID transition, the DAC steps through the VIDs at a
controlled slew rate. For example, the DAC may change a tick
(5mV) per 0.5µs, controlling output voltage VCORE slew rate at
10mV/µs.
FN6898.0
September 29, 2011
ISL6363
Figure 27 shows the waveforms of 1-tick VID transition. During
1-tick VID transition, the DAC output changes at approximately
15mV/µs slew rate, but the DAC cannot step through multiple
VIDs to control the slew rate. Instead, the control loop response
speed determines VCORE slew rate. Ideally, VCORE will follow the
FB pin voltage slew rate. However, the controller senses the
inductor current increase during the up transition, as the
Idroop_vid waveform shows, and will droop the output voltage
VCORE accordingly, making VCORE slew rate slow. Similar
behavior occurs during the down transition.
It is desired to let Ivid(t) cancel Idroop_vid(t). So there are:
To control VCORE slew rate during 1-tick VID transition, one can
add the Rvid-Cvid branch, whose current Ivid cancels Idroop_vid.
and:
When VCORE increases, the time domain expression of the
induced Idroop change is:
–t
-------------------------⎞
C out × LL dV core ⎛
C
× LL⎟
I droop ( t ) = ------------------------ × ------------------ × ⎜ 1 – e out
⎜
⎟
R droop
dt
⎝
⎠
(EQ. 43)
Where Cout is the total output capacitance.
In the mean time, the Rvid-Cvid branch current Ivid time domain
expression is:
–t
------------------------------⎞
dV fb ⎛
R
×C
I vid ( t ) = C vid × ------------ × ⎜ 1 – e vid vid⎟
⎜
⎟
dt
⎝
⎠
30
(EQ. 44)
dV fb
C out × LL dV core
C vid × ------------ = ------------------------ × -----------------R droop
dt
dt
(EQ. 45)
and:
R vid × C vid = C out × LL
(EQ. 46)
The result is expressed in Equation 47:
R vid = R droop
dV core
C out × LL ----------------dt
C vid = ------------------------ × -----------------R droop
dV fb
-----------dt
(EQ. 47)
(EQ. 48)
For example: given LL = 1.9mΩ, Rdroop = 2.37kΩ,
Cout = 1320µF, dVCORE/dt = 10mV/µs and dVfb/dt = 15mV/µs,
Equation 47 gives Rvid = 2.37kΩ and Equation 48 gives
Cvid = 700pF.
It is recommended to select the calculated Rvid value and start
with the calculated Cvid value and tweak it on the actual board to
get the best performance.
During normal transient response, the FB pin voltage is held
constant, therefore is virtual ground in small signal sense. The
Rvid - Cvid network is between the virtual ground and the real
ground, and hence has no effect on transient response.
FN6898.0
September 29, 2011
ISL6363
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not guaranteed. Please go to web to make
sure you have the latest Rev.
DATE
REVISION
9/29/11
FN6898.0
CHANGE
Initial Release.
Products
Intersil Corporation is a leader in the design and manufacture of high-performance analog semiconductors. The Company's products
address some of the industry's fastest growing markets, such as, flat panel displays, cell phones, handheld products, and notebooks.
Intersil's product families address power management and analog signal processing functions. Go to www.intersil.com/products for a
complete list of Intersil product families.
For a complete listing of Applications, Related Documentation and Related Parts, please see the respective device information page on
intersil.com: ISL6363
To report errors or suggestions for this datasheet, please go to www.intersil.com/askourstaff
FITs are available from our website at http://rel.intersil.com/reports/search.php
31
FN6898.0
September 29, 2011
ISL6363
Package Outline Drawing
L48.6x6
48 LEAD THIN QUAD FLAT NO-LEAD PLASTIC PACKAGE
Rev 1, 4/07
4X 4.4
6.00
44X 0.40
A
B
6
PIN 1
INDEX AREA
6
PIN #1 INDEX AREA
48
37
1
6.00
36
4 .40 ± 0.15
25
12
0.15
(4X)
13
24
0.10 M C A B
0.05 M C
TOP VIEW
48X 0.45 ± 0.10
4 48X 0.20
BOTTOM VIEW
SEE DETAIL "X"
0.10 C
BASE PLANE
MAX 0.80
(
SEATING PLANE
0.08 C
( 44 X 0 . 40 )
( 5. 75 TYP )
C
SIDE VIEW
4. 40 )
C
0 . 2 REF
5
( 48X 0 . 20 )
0 . 00 MIN.
0 . 05 MAX.
( 48X 0 . 65 )
DETAIL "X"
TYPICAL RECOMMENDED LAND PATTERN
NOTES:
1. Dimensions are in millimeters.
Dimensions in ( ) for Reference Only.
2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994.
3. Unless otherwise specified, tolerance : Decimal ± 0.05
4. Dimension b applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
5. Tiebar shown (if present) is a non-functional feature.
6. The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 indentifier may be
either a mold or mark feature.
32
FN6898.0
September 29, 2011
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