ISL6261IR7Z-T [INTERSIL]

Single-Phase Core Regulator for IMVP-6 Mobile CPUs; 单相核心稳压器,用于IMVP - 6移动处理器
ISL6261IR7Z-T
型号: ISL6261IR7Z-T
厂家: Intersil    Intersil
描述:

Single-Phase Core Regulator for IMVP-6 Mobile CPUs
单相核心稳压器,用于IMVP - 6移动处理器

稳压器
文件: 总34页 (文件大小:1197K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
ISL6261  
®
Data Sheet  
September 27, 2006  
FN9251.1  
®
Single-Phase Core Regulator for IMVP-6  
Mobile CPUs  
Features  
• Precision single-phase CORE voltage regulator  
- 0.5% system accuracy over temperature  
- Enhanced load line accuracy  
The ISL6261 is a single-phase buck regulator implementing  
lntel® IMVP-6® protocol, with embedded gate drivers.  
The heart of the ISL6261 is the patented R3 Technology™,  
Intersil’s Robust Ripple Regulator modulator. Compared with  
the traditional multi-phase buck regulator, the R3  
Technology™ has faster transient response. This is due to  
the R3 modulator commanding variable switching frequency  
during a load transient.  
• Internal gate driver with 2A driving capability  
• Microprocessor voltage identification input  
- 7-Bit VID input  
- 0.300V to 1.500V in 12.5mV steps  
- Support VID change on-the-fly  
• Multiple current sensing schemes supported  
- Lossless inductor DCR current sensing  
- Precision resistive current sensing  
lntel® Mobile Voltage Positioning (IMVP) is a smart voltage  
regulation technology effectively reducing power dissipation  
in lntel® Pentium processors. To boost battery life, the  
ISL6261 supports DPRSLRVR (deeper sleep) function and  
maximizes the efficiency via automatically changing  
operation modes. At heavy load in the active mode, the  
regulator commands the continuous conduction mode  
(CCM) operation. When the CPU enters deeper sleep mode,  
the ISL6261 enables diode emulation to maximize the  
efficiency at light load. Asserting the FDE pin of the ISL6261  
in deeper sleep mode will further decrease the switching  
frequency at light load and increase the regulator efficiency.  
• Thermal monitor  
• User programmable switching frequency  
• Differential remote voltage sensing at CPU die  
• Overvoltage, undervoltage, and overcurrent protection  
• Pb-free plus anneal available (RoHS compliant)  
Ordering Information  
TEMP  
A 7-bit digital-to-analog converter (DAC) allows dynamic  
adjustment of the core output voltage from 0.300V to 1.500V.  
The ISL6261 has 0.5% system voltage accuracy over  
temperature.  
PART NUMBER  
PART  
MARKING  
RANGE PACKAGE PKG.  
(°C) (Pb-FREE) DWG. #  
(NOTE)  
ISL6261CRZ  
ISL6261CRZ -10 to +100 40 Ld 6x6 L40.6x6  
QFN  
A unity-gain differential amplifier provides remote voltage  
sensing at the CPU die. This allows the voltage on the CPU  
die to be accurately measured and regulated per lntel®  
IMVP-6 specification. Current sensing can be implemented  
through either lossless inductor DCR sensing or precise  
resistor sensing. If DCR sensing is used, an NTC thermistor  
network will thermally compensates the gain and the time  
constant variations caused by the inductor DCR change.  
ISL6261CRZ-T ISL6261CRZ -10 to +100 40 Ld 6x6 L40.6x6  
QFN, T&R  
ISL6261CR7Z  
ISL6261CR7Z -10 to +100 48 Ld 7x7 L48.7x7  
QFN  
ISL6261CR7Z-T ISL6261CR7Z -10 to +100 48 Ld 7x7 L48.7x7  
QFN, T&R  
ISL6261IRZ  
ISL6261IRZ-T  
ISL6261IR7Z  
ISL6261IRZ  
-40 to +100 40 Ld 6x6 L40.6x6  
QFN  
ISL6261IRZ  
-40 to +100 40 Ld 6x6 L40.6x6  
QFN, T&R  
ISL6261IR7Z -40 to +100 48 Ld 7x7 L48.7x7  
QFN  
ISL6261IR7Z-T ISL6261IR7Z -40 to +100 48 Ld 7x7 L48.7x7  
QFN, T&R  
NOTE: Intersil Pb-free plus anneal products employ special Pb-free  
material sets; molding compounds/die attach materials and 100%  
matte tin plate termination finish, which are 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.  
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.  
1
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.  
Copyright Intersil Americas Inc. 2006. All Rights Reserved. R3 Technology™ is a trademark of Intersil Americas Inc.  
All other trademarks mentioned are the property of their respective owners.  
ISL6261  
Pinouts  
ISL6261  
(40 LD QFN)  
40 39 38 37 36 35 34 33 32 31  
FDE  
PGD_IN  
RBIAS  
VR_TT#  
NTC  
1
2
3
4
5
6
7
8
9
30 VID2  
29 VID1  
28 VID0  
27  
26  
25  
24  
23  
22  
VCCP  
LGATE  
VSSP  
GND PAD  
(BOTTOM)  
SOFT  
OCSET  
VW  
PHASE  
UGATE  
BOOT  
COMP  
FB 10  
21 NC  
11 12 13 14 15 16 17 18 19 20  
ISL6261  
(48 LD QFN)  
48 47 46 45 44 43 42 41 40 39 38 37  
1
2
36  
35  
34  
33  
PGOOD  
FDE  
NC  
NC  
NC  
NC  
3
PGD_IN  
RBIAS  
VR_TT#  
NTC  
4
5
32 NC  
6
31  
30  
29  
VCCP  
LGATE  
VSSP  
GND PAD  
(BOTTOM)  
7
SOFT  
OCSET  
VW  
8
9
28 PHASE  
UGATE  
27  
COMP  
10  
FB 11  
NC 12  
26 BOOT  
25 NC  
13 14 15 16 17 18 19 20 21 22 23 24  
FN9251.1  
September 27, 2006  
2
ISL6261  
Absolute Maximum Ratings  
Thermal Information  
Supply Voltage, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +7V  
Battery Voltage, VIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+28V  
Boot Voltage (BOOT). . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to +33V  
Boot to Phase Voltage (BOOT-PHASE). . . . . . . . . -0.3V to +7V(DC)  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to +9V(<10ns)  
Phase Voltage (PHASE) . . . . . . . . . -7V (<20ns Pulse Width, 10µJ)  
UGATE Voltage (UGATE) . . . . . . . . . . PHASE-0.3V (DC) to BOOT  
. . . . . . . . . . . . . .PHASE-5V (<20ns Pulse Width, 10µJ) to BOOT  
LGATE Voltage (LGATE) . . . . . . . . . . . . . . -0.3V (DC) to VDD+0.3V  
. . . . . . . . . . . . . . . . -2.5V (<20ns Pulse Width, 5µJ) to VDD+0.3V  
All Other Pins. . . . . . . . . . . . . . . . . . . . . . . . . .-0.3V to (VDD +0.3V)  
Open Drain Outputs, PGOOD, VR_TT# . . . . . . . . . . . . -0.3 to +7V  
HBM ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .>3kV  
Thermal Resistance (Typical)  
θ
JA (°C/W)  
θ
JC (°C/W)  
6x6 QFN Package (Notes 1, 2) . . . . . . 33  
7x7 QFN Package (Notes 1, 2) . . . . . . 30  
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . +150°C  
Maximum Storage Temperature Range. . . . . . . . . .-65°C to +150°C  
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . +300°C  
5.5  
5.5  
Recommended Operating Conditions  
Supply Voltage, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+5V ±5%  
Battery Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . +5V to 21V  
Ambient Temperature . . . . . . . . . . . . . . . . . . . . . . .-10°C to +100°C  
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . .-10°C to +125°C  
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the  
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.  
NOTE:  
1. 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.  
2. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside.  
Electrical Specifications VDD = 5V, TA = -10°C to +100°C, Unless Otherwise Specified.  
PARAMETER  
INPUT POWER SUPPLY  
+5V Supply Current  
SYMBOL  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
IVDD  
VR_ON = 3.3V  
-
3.1  
3.6  
1
mA  
µA  
µA  
µA  
V
VR_ON = 0V  
-
-
-
+3.3V Supply Current  
I3V3  
IVIN  
No load on CLK_EN# pin  
VR_ON = 0, VIN = 25V  
VDD Rising  
-
1
Battery Supply Current at VIN pin  
POR (Power-On Reset) Threshold  
-
-
-
1
PORr  
PORf  
4.35  
4.1  
4.5  
-
VDD Falling  
3.85  
V
SYSTEM AND REFERENCES  
System Accuracy  
%Error  
(Vcc_core  
No load, close loop, active mode,  
TA = 0°C to +100°C,  
-0.5  
-
0.5  
%
)
VID = 0.75-1.5V  
VID = 0.5-0.7375V  
VID = 0.3-0.4875V  
RRBIAS = 147kΩ  
-8  
-15  
1.45  
1.188  
-
-
-
8
15  
mV  
mV  
V
RBIAS Voltage  
RRBIAS  
VBOOT  
1.47  
1.2  
1.5  
1.49  
1.212  
-
Boot Voltage  
V
Maximum Output Voltage  
VCC_CORE  
(max)  
VID = [0000000]  
VID = [1100000]  
VID = [1111111]  
V
Minimum Output Voltage  
VCC_CORE  
(min)  
-
-
0.3  
0.0  
-
-
V
V
VID Off State  
CHANNEL FREQUENCY  
Nominal Channel Frequency  
fSW  
RFSET = 7kΩ,  
-
333  
-
-
kHz  
kHz  
V
comp = 2V  
Adjustment Range  
200  
500  
AMPLIFIERS  
Droop Amplifier Offset  
Error Amp DC Gain (Note 3)  
-0.3  
-
0.3  
-
mV  
dB  
AV0  
90  
FN9251.1  
September 27, 2006  
3
ISL6261  
Electrical Specifications VDD = 5V, TA = -10°C to +100°C, Unless Otherwise Specified. (Continued)  
PARAMETER  
SYMBOL  
TEST CONDITIONS  
MIN  
TYP  
MAX  
UNITS  
Error Amp Gain-Bandwidth Product  
(Note 3)  
GBW  
CL = 20pF  
CL = 20pF  
-
18  
-
MHz  
Error Amp Slew Rate (Note 3)  
FB Input Current  
SR  
-
-
5.0  
10  
-
V/µs  
nA  
IIN(FB)  
150  
SOFT-START CURRENT  
Soft-start Current  
ISS  
IGV  
-46  
±175  
-46  
-41  
±200  
-41  
-36  
±225  
-36  
µA  
µA  
µA  
µA  
µA  
Soft Geyserville Current  
Soft Deeper Sleep Entry Current  
Soft Deeper Sleep Exit Current  
Soft Deeper Sleep Exit Current  
|SOFT - REF|>100mV  
DPRSLPVR = 3.3V  
DPRSLPVR = 3.3V  
DPRSLPVR = 0V  
IC4  
IC4EA  
IC4EB  
36  
41  
46  
175  
200  
225  
GATE DRIVER DRIVING CAPABILITY (Note 4)  
UGATE Source Resistance  
UGATE Source Current  
UGATE Sink Resistance  
UGATE Sink Current  
RSRC(UGATE)  
500mA Source Current  
VUGATE_PHASE = 2.5V  
500mA Sink Current  
VUGATE_PHASE = 2.5V  
500mA Source Current  
VLGATE = 2.5V  
-
-
-
-
-
-
-
-
-
1
2
1.5  
Ω
A
ISRC(UGATE)  
RSNK(UGATE)  
ISNK(UGATE)  
RSRC(LGATE)  
ISRC(LGATE)  
RSNK(LGATE)  
ISNK(LGATE)  
RP(UGATE)  
-
1.5  
-
1
Ω
A
2
LGATE Source Resistance  
LGATE Source Current  
LGATE Sink Resistance  
LGATE Sink Current  
1
1.5  
-
Ω
A
2
500mA Sink Current  
VLGATE = 2.5V  
0.5  
4
0.9  
-
Ω
A
UGATE to PHASE Resistance  
1.1  
-
kΩ  
GATE DRIVER SWITCHING TIMING (Refer to Timing Diagram)  
UGATE Turn-on Propagation Delay  
LGATE Turn-on Propagation Delay  
BOOTSTRAP DIODE  
Forward Voltage  
tPDHU  
tPDHL  
PVCC = 5V, Output Unloaded  
PVCC = 5V, Output Unloaded  
20  
7
30  
15  
44  
30  
ns  
ns  
V
V
DDP = 5V, Forward Bias Current = 2mA  
R = 16V  
0.43  
-
0.58  
-
0.67  
1
V
Leakage  
μA  
POWER GOOD and PROTECTION MONITOR  
PGOOD Low Voltage  
PGOOD Leakage Current  
PGOOD Delay  
VOL  
IOH  
IPGOOD = 4mA  
-
0.11  
-
0.4  
1
V
PGOOD = 3.3V  
-1  
µA  
ms  
mV  
V
tpgd  
OVH  
OVHS  
CLK_EN# Low to PGOOD High  
VO rising above setpoint >1ms  
VO rising above setpoint >0.5µs  
I(Rbias) = 10µA  
5.5  
6.8  
200  
1.7  
10  
8.1  
Overvoltage Threshold  
Severe Overvoltage Threshold  
OCSET Reference Current  
OC Threshold Offset  
160  
1.675  
9.8  
240  
1.725  
10.2  
3.5  
µA  
mV  
mV  
DROOP rising above OCSET >120µs  
VO below set point for >1ms  
-3.5  
-360  
Undervoltage Threshold  
(VDIFF-SOFT)  
UVf  
-300  
-240  
LOGIC THRESHOLDS  
VR_ON, DPRSLPVR and PGD_IN  
Input Low  
VIL(3.3V)  
-
-
-
1
-
V
V
VR_ON, DPRSLPVR and PGD_IN  
Input High  
VIH(3.3V)  
2.3  
FN9251.1  
September 27, 2006  
4
ISL6261  
Electrical Specifications VDD = 5V, TA = -10°C to +100°C, Unless Otherwise Specified. (Continued)  
PARAMETER  
SYMBOL  
IIL  
TEST CONDITIONS  
Logic input is low  
MIN  
TYP  
MAX  
UNITS  
μA  
Leakage Current on VR_ON and  
PGD_IN  
-1  
-
0
0
-
1
IIH  
Logic input is high  
μA  
Leakage Current on DPRSLPVR  
IIL_DPRSLP  
IIH_DPRSLP  
VIL(1.0V)  
DPRSLPVR logic input is low  
DPRSLPVR logic input is high  
-1  
-
0
-
μA  
0.45  
-
1
μA  
DAC(VID0-VID6), PSI# and  
DPRSTP# Input Low  
-
0.3  
V
DAC(VID0-VID6), PSI# and  
DPRSTP# Input High  
VIH(1.0V)  
0.7  
-
-
V
Leakage Current of DAC(VID0-  
VID6) and DPRSTP#  
IIL  
DPRSLPVR logic input is low  
DPRSLPVR logic input is high  
-1  
-
0
-
μA  
μA  
IIH  
0.45  
1
THERMAL MONITOR  
NTC Source Current  
NTC = 1.3V  
V(NTC) falling  
I = 20mA  
53  
1.17  
-
60  
1.2  
5
67  
1.25  
9
µA  
V
Over-temperature Threshold  
VR_TT# Low Output Resistance  
CLK_EN# OUTPUT LEVELS  
CLK_EN# High Output Voltage  
CLK_EN# Low Output Voltage  
RTT  
VOH  
VOL  
3V3 = 3.3V, I = -4mA  
ICLK_EN# = 4mA  
2.9  
-
3.1  
-
V
V
0.18  
0.4  
NOTES:  
3. Guaranteed by characterization.  
4. Guaranteed by design.  
Gate Driver Timing Diagram  
PWM  
t
PDHU  
t
FU  
t
RU  
1V  
UGATE  
LGATE  
1V  
t
RL  
t
FL  
t
PDHL  
FN9251.1  
September 27, 2006  
5
ISL6261  
Functional Pin Description  
40 39 38 37 36 35 34 33 32 31  
FDE  
PGD_IN  
RBIAS  
VR_TT#  
NTC  
1
2
3
4
5
6
7
8
9
30 VID2  
29 VID1  
28 VID0  
27  
26  
25  
24  
23  
22  
VCCP  
LGATE  
VSSP  
GND PAD  
(BOTTOM)  
SOFT  
OCSET  
VW  
PHASE  
UGATE  
BOOT  
COMP  
FB 10  
21 NC  
11 12 13 14 15 16 17 18 19 20  
FDE  
VW  
Forced diode emulation enable signal. Logic high of FDE  
with logic low of DPRSTP# forces the ISL6261 to operate in  
diode emulation mode with an increased VW-COMP voltage  
window.  
A resistor from this pin to COMP programs the switching  
frequency (eg. 6.81K = 300kHz).  
COMP  
The output of the error amplifier.  
PGD_IN  
FB  
Digital Input. Suggest connecting to MCH_PWRGD, which  
indicates that VCC_MCH voltage is within regulation.  
The inverting input of the error amplifier.  
VDIFF  
RBIAS  
The output of the differential amplifier.  
A 147K resistor to VSS sets internal current reference.  
VSEN  
VR_TT#  
Remote core voltage sense input.  
Thermal overload output indicator with open-drain output.  
Over-temperature pull-down resistance is 10.  
RTN  
Remote core voltage sense return.  
NTC  
Thermistor input to VR_TT# circuit and a 60µA current  
source is connected internally to this pin.  
DROOP  
The output of the droop amplifier. DROOP-VO voltage is the  
droop voltage.  
SOFT  
A capacitor from this pin to GND pin sets the maximum slew  
rate of the output voltage. The SOFT pin is the non-inverting  
input of the error amplifier.  
DFB  
The inverting input of the droop amplifier.  
VO  
OCSET  
An input to the IC that reports the local output voltage.  
Overcurrent set input. A resistor from this pin to VO sets  
DROOP voltage limit for OC trip. A 10µA current source is  
connected internally to this pin.  
FN9251.1  
September 27, 2006  
6
ISL6261  
VSUM  
NC  
This pin is connected to one terminal of the capacitor in the  
current sensing R-C network.  
Not connected. Ground this pin in the practical layout.  
VID0, VID1, VID2, VID3, VID4, VID5, VID6  
VIN  
VID input with VID0 as the least significant bit (LSB) and  
VID6 as the most significant bit (MSB).  
Power stage input voltage. It is used for input voltage feed  
forward to improve the input line transient performance.  
VR_ON  
VSS  
VR enable pin. A logic high signal on this pin enables the  
regulator.  
Signal ground. Connect to controller local ground.  
VDD  
DPRSLPVR  
5V control power supply.  
Deeper sleep enable signal. A logic high indicates that the  
microprocessor is in Deeper Sleep Mode and also indicates  
a slow Vo slew rate with 41μA discharging or charging the  
SOFT cap.  
BOOT  
Upper gate driver supply voltage. An internal bootstrap diode  
is connected to the VCCP pin.  
DPRSTP#  
UGATE  
Deeper sleep slow wake up signal. A logic low signal on this  
pin indicates that the microprocessor is in Deeper Sleep  
Mode.  
The upper-side MOSFET gate signal.  
PHASE  
The phase node. This pin should connect to the source of  
upper MOSFET.  
CLK_EN#  
Digital output for system PLL clock. Goes active 20µs after  
PGD_IN is active and Vcore is within 10% of boot voltage.  
VSSP  
The return path of the lower gate driver.  
3V3  
3.3V supply voltage for CLK_EN#.  
LGATE  
The lower-side MOSFET gate signal.  
PGOOD  
Power good open-drain output. Needs to be pulled up  
externally by a 680 resistor to VCCP or 1.9k to 3.3V.  
VCCP  
5V power supply for the gate driver.  
FN9251.1  
September 27, 2006  
7
ISL6261  
Function Block Diagram  
FIGURE 1. SIMPLIFIED FUNCTIONAL BLOCK DIAGRAM OF ISL6261  
FN9251.1  
September 27, 2006  
8
ISL6261  
Simplified Application Circuit for DCR Current Sensing  
V
+5  
V+3.3  
Vin  
R
4
C
4
3V3 VDD VCCP  
R
5
RBIAS  
NTC  
VIN  
R
6
C
8
C
5
UGATE  
BOOT  
SOFT  
VR_TT#  
Lo  
C
6
VR_TT#  
Vo  
PHASE  
VID<0:6>  
DPRSTP#  
VIDs  
Co  
DPRSTP#  
DPRSLPVR  
FDE  
DPRSLPVR  
LGATE  
VSSP  
MCH_PWRGD  
CLK_ENABLE#  
VR_ON  
PGD_IN  
CLK_EN#  
VR_ON  
PGOOD  
VSEN  
R
8
VSUM  
VO  
IMVP6_PWRGD  
VCC-SENSE  
VSS-SENSE  
R
9
C
9
NTC  
Network  
RTN  
R
7
ISL6261  
C
R
10  
7
C
3
R
VW  
11  
OCSET  
C
2
R
C
10  
2
COMP  
FB  
DFB  
R
12  
C
1
R
3
DROOP  
VDIFF  
R
1
VSS  
FIGURE 2. ISL6261-BASED IMVP-6® SOLUTION WITH INDUCTOR DCR CURRENT SENSING  
FN9251.1  
September 27, 2006  
9
ISL6261  
Simplified Application Circuit for Resistive Current Sensing  
V
+5  
V+3.3  
Vin  
R
4
C
4
3V3 VDD VCCP  
R
R
C
5
RBIAS  
NTC  
VIN  
6
5
C
8
UGATE  
BOOT  
SOFT  
VR_TT#  
Lo  
C
6
Rsen  
VR_TT#  
Vo  
PHASE  
VID<0:6>  
DPRSTP#  
VIDs  
Co  
DPRSTP#  
DPRSLPVR  
FDE  
DPRSLPVR  
LGATE  
VSSP  
MCH_PWRGD  
CLK_ENABLE#  
VR_ON  
PGD_IN  
CLK_EN#  
VR_ON  
PGOOD  
VSEN  
R
8
VSUM  
VO  
IMVP6_PWRGD  
VCC-SENSE  
VSS-SENSE  
C
9
RTN  
R
7
ISL6261  
C
R
10  
7
C
3
R
R
VW  
11  
OCSET  
C
2
R
C
10  
2
COMP  
FB  
DFB  
12  
C
1
R
3
DROOP  
VDIFF  
R
1
VSS  
FIGURE 3. ISL6261-BASED IMVP-6® SOLUTION WITH RESISTIVE CURRENT SENSING  
FN9251.1  
September 27, 2006  
10  
ISL6261  
Theory of Operation  
The ISL6261 is a single-phase regulator implementing Intel®  
IMVP-6® protocol and includes an integrated gate driver for  
reduced system cost and board area. The ISL6261 IMVP-6®  
solution provides optimum steady state and transient  
performance for microprocessor core voltage regulation  
applications up to 25A. Implementation of diode emulation  
mode (DEM) operation further enhances system efficiency.  
VDD  
10mV/us  
Vboot  
VR_ON  
100us  
2mV/us  
SOFT &VO  
~20us  
The heart of the ISL6261 is the patented R3 Technology™,  
Intersil’s Robust Ripple Regulator modulator. The R3™  
modulator combines the best features of fixed frequency and  
hysteretic PWM controllers while eliminating many of their  
shortcomings. The ISL6261 modulator internally synthesizes  
an analog of the inductor ripple current and uses hysteretic  
comparators on those signals to establish PWM pulses.  
Operating on the large-amplitude and noise-free synthesized  
signals allows the ISL6261 to achieve lower output ripple  
and lower phase jitter than either conventional hysteretic or  
fixed frequency PWM controllers. Unlike conventional  
hysteretic converters, the ISL6261 has an error amplifier that  
allows the controller to maintain 0.5% voltage regulation  
accuracy throughout the VID range from 0.75V to 1.5V.  
PGD_IN  
CLK_EN#  
~7ms  
IMVP-VI PGOOD  
FIGURE 4. SOFT-START WAVEFORMS USING A 20nF SOFT  
CAPACITOR  
Static Operation  
After the startup sequence, the output voltage will be  
regulated to the value set by the VID inputs per Table 1,  
which is presented in the lntel® IMVP-6® specification. The  
ISL6261 regulates the output voltage with ±0.5% accuracy  
over the range of 0.7V to 1.5V.  
The hysteretic window voltage is with respect to the error  
amplifier output. Therefore the load current transient results  
in increased switching frequency, which gives the R3™  
regulator a faster response than conventional fixed  
frequency PWM regulators.  
A true differential amplifier remotely senses the core voltage  
to precisely control the voltage at the microprocessor die.  
VSEN and RTN pins are the inputs to the differential  
amplifier.  
Start-up Timing  
With the controller’s VDD pin voltage above the POR  
threshold, the start-up sequence begins when VR_ON  
exceeds the 3.3V logic HIGH threshold. In approximately  
100μs, SOFT and VO start ramping to the boot voltage of  
1.2V. At startup, the regulator always operates in continuous  
current mode (CCM), regardless of the control signals.  
During this interval, the SOFT cap is charged by a 41μA  
current source. If the SOFT capacitor is 20nF, the SOFT  
ramp will be 2mV/μs for a soft-start time of 600μs. Once VO  
is within 10% of the boot voltage and PGD_IN is HIGH for six  
PWM cycles (20µs for 300kHz switching frequency),  
CLK_EN# is pulled LOW, and the SOFT cap is  
As the load current increases from zero, the output voltage  
droops from the VID value proportionally to achieve the  
IMVP-6® load line. The ISL6261 can sense the inductor  
current through the intrinsic series resistance of the  
inductors, as shown in Figure 2, or through a precise resistor  
in series with the inductor, as shown in Figure 3. The  
inductor current information is fed to the VSUM pin, which is  
the non-inverting input to the droop amplifier. The DROOP  
pin is the output of the droop amplifier, and DROOP-VO  
voltage is a high-bandwidth analog representation of the  
inductor current. This voltage is used as an input to a  
differential amplifier to achieve the IMVP-6® load line, and  
also as the input to the overcurrent protection circuit.  
charged/discharged by approximate 200µA and VO slews at  
10mV/μs to the voltage set by the VID pins. In approximately  
7ms, PGOOD is asserted HIGH. Figure 4 shows typical  
startup timing.  
When using inductor DCR current sensing, an NTC  
thermistor is used to compensate the positive temperature  
coefficient of the copper winding resistance to maintain the  
load-line accuracy.  
PGD_IN Latch  
It should be noted that PGD_IN going low will cause the  
converter to latch off. Toggling PGD_IN won’t clear the latch.  
Toggling VR_ON will clear it. This feature allows the  
converter to respond to other system voltage outages  
immediately.  
The switching frequency of the ISL6261 controller is set by  
the resistor RFSET between pins VW and COMP, as shown in  
Figures 2 and 3.  
FN9251.1  
September 27, 2006  
11  
ISL6261  
TABLE 1. VID TABLE FROM INTEL IMVP-6 SPECIFICATION  
(Continued)  
TABLE 1. VID TABLE FROM INTEL IMVP-6 SPECIFICATION  
VID6 VID5 VID4 VID3 VID2 VID1 VID0  
Vo (V)  
0.9750  
0.9625  
0.9500  
0.9375  
0.9250  
0.9125  
0.9000  
0.8875  
0.8750  
0.8625  
0.8500  
0.8375  
0.8250  
0.8125  
0.8000  
0.7875  
0.7750  
0.7625  
0.7500  
0.7375  
0.7250  
0.7125  
0.7000  
0.6875  
0.6750  
0.6625  
0.6500  
0.6375  
0.6250  
0.6125  
0.6000  
0.5875  
0.5750  
0.5625  
0.5500  
0.5375  
0.5250  
0.5125  
0.5000  
0.4875  
0.4750  
0.4625  
VID6 VID5 VID4 VID3 VID2 VID1 VID0  
Vo (V)  
1.5000  
1.4875  
1.4750  
1.4625  
1.4500  
1.4375  
1.4250  
1.4125  
1.4000  
1.3875  
1.3750  
1.3625  
1.3500  
1.3375  
1.3250  
1.3125  
1.3000  
1.2875  
1.2750  
1.2625  
1.2500  
1.2375  
1.2250  
1.2125  
1.2000  
1.1875  
1.1750  
1.1625  
1.1500  
1.1375  
1.1250  
1.1125  
1.1000  
1.0875  
1.0750  
1.0625  
1.0500  
1.0375  
1.0250  
1.0125  
1.0000  
0.9875  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
FN9251.1  
September 27, 2006  
12  
ISL6261  
TABLE 1. VID TABLE FROM INTEL IMVP-6 SPECIFICATION  
(Continued)  
TABLE 1. VID TABLE FROM INTEL IMVP-6 SPECIFICATION  
(Continued)  
VID6 VID5 VID4 VID3 VID2 VID1 VID0  
Vo (V)  
0.4500  
0.4375  
0.4250  
0.4125  
0.4000  
0.3875  
0.3750  
0.3625  
0.3500  
0.3375  
0.3250  
0.3125  
0.3000  
0.2875  
0.2750  
0.2625  
0.2500  
0.2375  
0.2250  
0.2125  
0.2000  
0.1875  
0.1750  
VID6 VID5 VID4 VID3 VID2 VID1 VID0  
Vo (V)  
0.1625  
0.1500  
0.1375  
0.1250  
0.1125  
0.1000  
0.0875  
0.0750  
0.0625  
0.0500  
0.0375  
0.0250  
0.0125  
0.0000  
0.0000  
0.0000  
0.0000  
0.0000  
0.0000  
0.0000  
0.0000  
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
TABLE 2. CONTROL SIGNAL TRUTH TABLES FOR OPERATIONAL MODES OF ISL6261  
VW-COMP WINDOW  
VOLTAGE INCREASE  
DPRSTP#  
FDE  
DPRSLPVR  
OPERATIONAL MODE  
Forced CCM  
0
0
0
0%  
Control  
Signal  
Logic  
0
0
1
0
1
x
1
x
x
Diode Emulation Mode  
Enhanced Diode Emulation Mode  
Forced CCM  
0%  
33%  
0%  
FN9251.1  
September 27, 2006  
13  
ISL6261  
based on load current. Light-load efficiency is increased in  
High Efficiency Operation Mode  
both active mode and deeper sleep mode.  
The operational modes of the ISL6261 depend on the  
control signal states of DPRSTP#, FDE, and DPRSLPVR, as  
shown in Table 2. These control signals can be tied to lntel®  
IMVP-6® control signals to maintain the optimal system  
configuration for all IMVP-6® conditions.  
CPU mode-transition sequences often occur in concert with  
VID changes. The ISL6261 employs carefully designed  
mode-transition timing to work in concert with the VID  
changes.  
DPRSTP# = 0, FDE = 0 and DPRSLPVR = 1 enables the  
ISL6261 to operate in diode emulation mode (DEM) by  
monitoring the low-side FET current. In diode emulation  
mode, when the low-side FET current flows from source to  
drain, it turns on as a synchronous FET to reduce the  
conduction loss. When the current reverses its direction  
trying to flow from drain to source, the ISL6261 turns off the  
low-side FET to prevent the output capacitor from  
discharging through the inductor, therefore eliminating the  
extra conduction loss. When DEM is enabled, the regulator  
works in automatic discontinuous conduction mode (DCM),  
meaning that the regulator operates in CCM in heavy load,  
and operates in DCM in light load. DCM in light load  
decreases the switching frequency to increase efficiency.  
This mode can be used to support the deeper sleep mode of  
the microprocessor.  
The ISL6261 is equipped with internal counters to prevent  
control signal glitches from triggering unintended mode  
transitions. For example: Control signals lasting less than  
seven switching periods will not enable the diode emulation  
mode.  
Dynamic Operation  
The ISL6261 responds to VID changes by slewing to new  
voltages with a dv/dt set by the SOFT capacitor and the logic  
of DPRSLPVR. If CSOFT = 20nF and DPRSLPVR = 0, the  
output voltage will move at a maximum dv/dt of ±10mV/μs  
for large changes. The maximum dv/dt can be used to  
achieve fast recovery from Deeper Sleep to Active mode. If  
CSOFT = 20nF and DPRSLPVR = 1, the output voltage will  
move at a dv/dt of ±2mV/μs for large changes. The slow  
dv/dt into and out of deeper sleep mode will minimize the  
audible noise. As the output voltage approaches the VID  
command value, the dv/dt moderates to prevent overshoot.  
The ISL6261 is IMVP-6® compliant for DPRSTP# and  
DPRSLPVR logic.  
DPRSTP# = 0 and FDE = 1 enables the enhanced diode  
emulation mode (EDEM), which increases the VW-COMP  
window voltage by 33%. This further decreases the  
switching frequency at light load to boost efficiency in the  
deeper sleep mode.  
Intersil R3™ has an intrinsic voltage feed forward function.  
High-speed input voltage transients have little effect on the  
output voltage.  
For other combinations of DPRSTP#, FDE, and  
DPRSLPVR, the ISL6261 operates in forced CCM.  
Intersil R3™ commands variable switching frequency during  
transients to achieve fast response. Upon load application,  
the ISL6261 will transiently increase the switching frequency  
to deliver energy to the output more quickly. Compared with  
steady state operation, the PWM pulses during load  
application are generated earlier, which effectively increases  
the duty cycle and the response speed of the regulator.  
Upon load release, the ILS6261 will transiently decrease the  
switching frequency to effectively reduce the duty cycle to  
achieve fast response.  
The ISL6261 operational modes can be set according to  
CPU mode signals to achieve the best performance. There  
are two options: (1) Tie FDE to DPRSLPVR, and tie  
DPRSTP# and DPRSLPVR to the corresponding CPU mode  
signals. This configuration enables EDEM in deeper sleep  
mode to increase efficiency. (2) Tie FDE to “1” and  
DPRSTP# to “0” permanently, and tie DPRSLPVR to the  
corresponding CPU mode signal. This configuration sets the  
regulator in EDEM all the time. The regulator will enter DCM  
TABLE 3. FAULT-PROTECTION SUMMARY OF ISL6261  
FAULT DURATION PRIOR  
TO PROTECTION  
FAULT TYPE  
Overcurrent fault  
PROTECTION ACTIONS  
PWM tri-state, PGOOD latched low  
PWM tri-state, PGOOD latched low  
FAULT RESET  
VR_ON toggle or VDD toggle  
VR_ON toggle or VDD toggle  
VDD toggle  
120μs  
Way-Overcurrent fault  
Overvoltage fault (1.7V)  
< 2μs  
Immediately  
Low-side FET on until Vcore < 0.85V, then PWM tri-  
state, PGOOD latched low (OV-1.7V always)  
Overvoltage fault  
(+200mV)  
1ms  
PWM tri-state, PGOOD latched low  
PWM tri-state, PGOOD latched low  
VR_TT# goes high  
VR_ON toggle or VDD toggle  
VR_ON toggle or VDD toggle  
N/A  
Undervoltage fault  
(-300mV)  
1ms  
Over-temperature fault  
(NTC<1.18)  
Immediately  
FN9251.1  
September 27, 2006  
14  
ISL6261  
threshold, the VR_TT# pin is pulled low indicating the need  
Protection  
for thermal throttling to the system oversight processor. No  
other action is taken within the ISL6261.  
The ISL6261 provides overcurrent (OC), overvoltage (OV),  
undervoltage (UV) and over-temperature (OT) protections as  
shown in Table 3.  
Component Selection and Application  
Overcurrent is detected through the droop voltage, which is  
designed as described in the “Component Selection and  
Application” section. The OCSET resistor sets the  
overcurrent protection level. An overcurrent fault will be  
declared when the droop voltage exceeds the overcurrent  
set point for more than 120µs. A way-overcurrent fault will be  
declared in less than 2µs when the droop voltage exceeds  
twice the overcurrent set point. In both cases, the UGATE  
and LGATE outputs will be tri-stated and PGOOD will go low.  
Soft-Start and Mode Change Slew Rates  
The ISL6261 commands two different output voltage slew  
rates for various modes of operation. The slow slew rate  
reduces the inrush current during startup and the audible  
noise during the entry and the exit of Deeper Sleep Mode.  
The fast slew rate enhances the system performance by  
achieving active mode regulation quickly during the exit of  
Deeper Sleep Mode. The SOFT current is bidirectional ⎯  
charging the SOFT capacitor when the output voltage is  
commanded to rise, and discharging the SOFT capacitor  
when the output voltage is commanded to fall.  
The over-current condition is detected through the droop  
voltage. The droop voltage is equal to Icore×Rdroop, where  
Rdroop is the load line slope. A 10μA current source flows out  
Figure 5 shows the circuitry on the SOFT pin. The SOFT pin,  
the non-inverting input of the error amplifier, is connected to  
ground through capacitor CSOFT. ISS is an internal current  
source connected to the SOFT pin to charge or discharge  
of the OCSET pin and creates a voltage drop across ROCSET  
(shown as R10 in Figure 2). Overcurrent is detected when  
the droop voltage exceeds the voltage across ROCSET  
.
Equation 1 gives the selection of ROCSET  
.
C
SOFT. The ISL6261 controls the output voltage slew rate by  
IOC × Rdroop  
10μA  
(EQ. 1)  
connecting or disconnecting another internal current source  
IZ to the SOFT pin, depending on the state of the system, i.e.  
Startup or Active mode, and the logic state on the  
DPRSLPVR pin. The SOFT-START CURRENT section of  
the Electrical Specification Table shows the specs of these  
two current sources.  
ROCSET  
=
For example: The desired over current trip level, Ioc, is 30A,  
droop is 2.1mΩ, Equation 1 gives ROCSET = 6.3k.  
R
Undervoltage protection is independent of the overcurrent  
limit. A UV fault is declared when the output voltage is lower  
than (VID-300mV) for more than 1ms. The gate driver  
outputs will be tri-stated and PGOOD will go low. Note that a  
practical core regulator design usually trips OC before it trips  
UV.  
ISS  
IZ  
Internal to  
ISL6261  
There are two levels of overvoltage protection and response.  
An OV fault is declared when the output voltage exceeds the  
VID by +200mV for more than 1ms. The gate driver outputs  
will be tri-stated and PGOOD will go low. The inductor  
current will decay through the low-side FET body diode.  
Toggling of VR_ON or bringing VDD below 4V will reset the  
fault latch. A way-overvoltage (WOV) fault is declared  
immediately when the output voltage exceeds 1.7V. The  
ISL6261 will latch PGOOD low and turn on the low-side  
FETs. The low-side FETs will remain on until the output  
voltage drops below approximately 0.85V, then all the FETs  
are turned off. If the output voltage again rises above 1.7V,  
the protection process repeats. This mechanism provides  
maximum protection against a shorted high-side FET while  
preventing the output from ringing below ground. Toggling  
VR_ON cannot reset the WOV protection; recycling VDD will  
reset it. The WOV detector is active all the time, even when  
other faults are declared, so the processor is still protected  
against the high-side FET leakage while the FETs are  
commanded off.  
Error  
Ampliflier  
CSOFT  
VREF  
FIGURE 5. SOFT PIN CURRENT SOURCES FOR FAST AND  
SLOW SLEW RATES  
I
SS is 41μA typical and is used during startup and mode  
changes. When connected to the SOFT pin, IZ adds to ISS to  
get a larger current, labelled IGV in the Electrical  
Specification Table, on the SOFT pin. IGV is typically 200μA  
with a minimum of 175μA.  
The IMVP-6® specification reveals the critical timing  
associated with regulating the output voltage. SLEWRATE,  
The ISL6261 has a thermal throttling feature. If the voltage  
on the NTC pin goes below the 1.2V over-temperature  
FN9251.1  
September 27, 2006  
15  
ISL6261  
10uA  
R
ocset  
OCSET  
I
phase  
L
OC  
DCR  
V
o
R
s
VSUM  
DFB  
C
o
Internal to  
ISL6261  
DROOP  
ESR  
DROOP  
VO  
1
1000pF  
0~10  
VSEN  
RTN  
VCC-SENSE  
VSS-SENSE  
To Processor  
Socket Kelvin  
Conections  
1
1000pF  
330pF  
VDIFF  
FIGURE 6. SIMPLIFIED VOLTAGE DROOP CIRCUIT WITH CPU-DIE VOLTAGE SENSING AND INDUCTOR DCR CURRENT SENSING  
given in the IMVP-6® specification, determines the choice of  
Startup Operation - CLK_EN# and PGOOD  
the SOFT capacitor, CSOFT, through the following equation:  
The ISL6261 provides a 3.3V logic output pin for CLK_EN#.  
IGV  
The system 3.3V voltage source connects to the 3V3 pin,  
which powers internal circuitry that is solely devoted to the  
CLK_EN# function. The output is a CMOS signal with 4mA  
sourcing and sinking capability. CMOS logic eliminates the  
need for an external pull-up resistor on this pin, eliminating  
the loss on the pull-up resistor caused by CLK_EN# being  
low in normal operation. This prolongs battery run time. The  
3.3V supply should be decoupled to digital ground, not to  
analog ground, for noise immunity.  
(EQ. 2)  
CSOFT  
=
SLEWRATE  
If SLEWRATE is 10mV/μs, and IGV is typically 200μA, CSOFT  
is calculated as  
(EQ. 3)  
CSOFT = 200μA  
(
10mV μs = 20nF  
)
Choosing 0.015μF will guarantee 10mV/μs SLEWRATE at  
minimum IGV value. This choice of CSOFT controls the  
startup slew rate as well. One should expect the output  
voltage to slew to the Boot value of 1.2V at a rate given by  
the following equation:  
At startup, CLK_EN# remains high until 20μs after PGD_IN  
going high, and Vcc-core is regulated at the Boot voltage.  
The ISL6261 triggers an internal timer for the  
IMVP6_PWRGD signal (PGOOD pin). This timer allows  
PGOOD to go high approximately 7ms after CLK_EN# goes  
low.  
dVsoft  
dt  
Iss  
41μA  
mV  
(EQ. 4)  
=
=
= 2.8  
μs  
CSOFT 0.015μF  
Selecting Rbias  
Static Mode of Operation - Processor Die Sensing  
To properly bias the ISL6261, a reference current needs to be  
derived by connecting a 147k, 1% tolerance resistor from the  
RBIAS pin to ground. This provides a very accurate 10μA  
current source from which OCSET reference current is derived.  
Remote sensing enables the ISL6261 to regulate the core  
voltage at a remote sensing point, which compensates for  
various resistive voltage drops in the power delivery path.  
The VSEN and RTN pins of the ISL6261 are connected to  
Kelvin sense leads at the die of the processor through the  
processor socket. (The signal names are Vcc_sense and  
Vss_sense respectively). Processor die sensing allows the  
voltage regulator to tightly control the processor voltage at  
the die, free of the inconsistencies and the voltage drops due  
Caution should used in layout: This resistor should be  
placed in the close proximity of the RBIAS pin and be  
connected to good quality signal ground. Do not connect any  
other components to this pin, as they will negatively impact  
the performance. Capacitance on this pin may create  
instabilities and should be avoided.  
FN9251.1  
September 27, 2006  
16  
ISL6261  
to layouts. The Kelvin sense technique provides for  
extremely tight load line regulation at the processor die side.  
These traces should be laid out as noise sensitive traces.  
For optimum load line regulation performance, the traces  
connecting these two pins to the Kelvin sense leads of the  
processor should be laid out away from rapidly rising voltage  
nodes (switching nodes) and other noisy traces. Common  
mode and differential mode filters are recommended as  
shown in Figure 6. The recommended filter resistance range  
is 0~10Ω so it does not interact with the 50k input resistance  
of the differential amplifier. The filter resistor may be inserted  
between VCC-SENSE and the VSEN pin. Another option is  
to place one between VCC-SENSE and the VSEN pin and  
another between VSS-SENSE and the RTN pin. The need of  
these filters also depends on the actual board layout and the  
noise environment.  
54uA  
6uA  
Internal to  
ISL6261  
VR_TT#  
NTC  
SW1  
VNTC  
RNTC  
SW2  
RS  
1.23V  
1.20V  
FIGURE 7. CIRCUITRY ASSOCIATED WITH THE THERMAL  
THROTTLING FEATURE  
Since the voltage feedback is sensed at the processor die, if  
the CPU is not installed, the regulator will drive the output  
voltage all the way up to damage the output capacitors due  
to lack of output voltage feedback. Ropn1 and Ropn2 are  
recommended, as shown in Figure 6, to prevent this  
potential issue. Ropn1 and Ropn2, typically ranging  
20~100Ω, provide voltage feedback from the regulator local  
output in the absence of the CPU.  
Figure 7 shows the circuitry associated with the thermal  
throttling feature of the ISL6261. At low temperature, SW1 is  
on and SW2 connects to the 1.20V side. The total current  
going into the NTC pin is 60µA. The voltage on the NTC pin  
is higher than 1.20V threshold voltage and the comparator  
output is low. VR_TT# is pulled up high by an external  
resistor. Temperature increase will decrease the NTC  
thermistor resistance. This decreases the NTC pin voltage.  
When the NTC pin voltage drops below 1.2V, the comparator  
output goes high to pull VR_TT# low, signalling a thermal  
throttle. In addition, SW1 turns off and SW2 connects to  
1.23V, which decreases the NTC pin current by 6µA and  
increases the threshold voltage by 30mV. The VR_TT#  
signal can be used by the system to change the CPU  
operation and decrease the power consumption. As the  
temperature drops, the NTC pin voltage goes up. If the NTC  
pin voltage exceeds 1.23V, VR_TT# will be pulled high.  
Figure 8 illustrates the temperature hysteresis feature of  
Setting the Switching Frequency - FSET  
3
The R modulator scheme is not a fixed frequency PWM  
architecture. The switching frequency increases during the  
application of a load to improve transient performance.  
It also varies slightly depending on the input and output  
voltages and output current, but this variation is normally  
less than 10% in continuous conduction mode.  
Resistor R  
(R in Figure 2), connected between the VW  
7
fset  
and COMP pins of the ISL6261, sets the synthetic ripple  
window voltage, and therefore sets the switching frequency.  
This relationship between the resistance and the switching  
frequency in CCM is approximately given by the following  
equation.  
VR_TT#. T and T (T >T ) are two threshold temperatures.  
1
2
1
2
VR_TT# goes low when the temperature is higher than T  
1
and goes high when the temperature is lower than T .  
2
VR_TT#  
Logic_1  
(EQ. 5)  
Rfset  
(
k  
)
=
(
period(μs) 0.29 × 2.33  
)
In diode emulation mode, the ISL6261 stretches the  
switching period. The switching frequency decreases as the  
load becomes lighter. Diode emulation mode reduces the  
switching loss at light load, which is important in conserving  
battery power.  
Logic_0  
T 2  
T 1  
T (oC)  
Voltage Regulator Thermal Throttling  
FIGURE 8. VR_TT# TEMPERATURE HYSTERISIS  
®
®
lntel IMVP-6 technology supports thermal throttling of the  
processor to prevent catastrophic thermal damage to the  
voltage regulator. The ISL6261A features a thermal monitor  
sensing the voltage across an externally placed negative  
temperature coefficient (NTC) thermistor. Proper selection  
and placement of the NTC thermistor allows for detection of  
a designated temperature rise by the system.  
FN9251.1  
September 27, 2006  
17  
ISL6261  
The NTC thermistor’s resistance is approximately given by  
the following formula:  
Once R  
and R is designed, the actual NTC resistance  
NTCTo s  
at T and the actual T temperature can be found in:  
2
2
1
1
(EQ. 13)  
(EQ. 14)  
RNTC _T 2 = 2.78kΩ + RNTC _T  
b(  
e  
)
(EQ. 6)  
1
T + 273 To + 273  
R
(T) = R  
NTC  
NTCTo  
1
T2 _ actual  
=
273  
T is the temperature of the NTC thermistor and b is a  
constant determined by the thermistor material. T is the  
reference temperature at which the approximation is  
R
1
NTC _T2  
ln(  
) +1 (273 +To )  
o
b
RNTCTo  
derived. The most commonly used T is 25°C. For most  
commercial NTC thermistors, there is b = 2750k, 2600k,  
4500k or 4250k.  
One example of using Equations 10, 11 and 12 to design a  
thermal throttling circuit with the temperature hysteresis  
o
100°C to 105°C is illustrated as follows. Since T = 105°C  
1
and T = 100°C, if we use a Panasonic NTC with b = 4700,  
Equation 9 gives the required NTC nominal resistance as  
2
From the operation principle of VR_TT#, the NTC resistor  
satisfies the following equation group:  
RNTC_To = 431k  
1.20V  
(EQ. 7)  
RNTC(T ) + Rs =  
= 20k  
1
60μA  
The NTC thermistor datasheet gives the resistance ratio as  
0.03956 at 100°C and 0.03322 at 105°C. The b value of  
4700k in Panasonic datasheet only covers up to 85°C;  
therefore, using Equation 11 is more accurate for 100°C  
design and the required NTC nominal resistance at 25°C is  
438kΩ. The closest NTC resistor value from manufacturers  
is 470kΩ. So Equation 12 gives the series resistance as  
follows:  
1.23V  
54μA  
(EQ. 8)  
RNTC(T2 ) + Rs =  
= 22.78kΩ  
From Equation 7 and Equation 8, the following can be  
derived:  
(EQ. 9)  
RNTC(T2 )RNTC(T ) = 2.78k  
1
Substitution of Equation 6 into Equation 9 yields the required  
nominal NTC resistor value:  
Rs = 20kΩ − RNTC _105C = 20kΩ 15.61kΩ = 4.39kΩ  
The closest standard value is 4.42kΩ. Furthermore,  
1
b(  
)
To +273  
Equation 13 gives the NTC resistance at T :  
2
2.78ke  
(EQ. 10)  
RNTCTo  
=
1
1
RNTC _T 2 = 2.78kΩ + RNTC _T =18.39kΩ  
b(  
b(  
)
1
T2 +273  
T +273  
1
e
) e  
The NTC branch is designed to have a 470k NTC and a  
4.42k resistor in series. The part number of the NTC  
thermistor is ERTJ0EV474J. It is a 0402 package. The NTC  
thermistor should be placed in the spot that gives the best  
indication of the temperature of the voltage regulator. The  
actual temperature hysteretic window is approximately  
105°C to 100°C.  
In some cases, the constant b is not accurate enough to  
approximate the resistor value; manufacturers provide the  
resistor ratio information at different temperatures. The  
nominal NTC resistor value may be expressed in another  
way as follows:  
2.78k  
RNTCTo  
=
Λ
Λ
(EQ. 11)  
RNTC (T2 )RNTC (T )  
1
Λ
where R NTC (T) is the normalized NTC resistance to its  
nominal value. The normalized resistor value on most NTC  
thermistor datasheets is based on the value at 25°C.  
Once the NTC thermistor resistor is determined, the series  
resistor can be derived by:  
1.20V  
(EQ. 12)  
Rs =  
RNTC(T1 ) = 20kR  
NTC_T1  
60μA  
FN9251.1  
September 27, 2006  
18  
ISL6261  
10uA  
R
ocset  
OCSET  
VO  
OC  
R
s
VSUM  
DFB  
Internal to  
ISL6261  
DROOP  
V
Io DCR  
DROOP  
VO  
dcr  
R
R
series  
ntc  
R
1
par  
(Rntc+Rseries) Rpar  
Rntc+Rseries+Rpar  
R
n
FIGURE 9. EQUIVALENT MODEL FOR DROOP CIRCUIT USING DCR SENSING  
G1, the gain of V to V  
temperature of the NTC thermistor:  
, is also dependent on the  
Static Mode of Operation - Static Droop Using DCR  
Sensing  
n
DCR  
Δ
The ISL6261 has an internal differential amplifier to  
accurately regulate the voltage at the processor die.  
Rn (T)  
G1(T)=  
(EQ. 17)  
Rn (T) + Rs  
For DCR sensing, the process to compensate the DCR  
resistance variation takes several iterative steps. Figure 2  
shows the DCR sensing method. Figure 9 shows the  
simplified model of the droop circuitry. The inductor DC  
current generates a DC voltage drop on the inductor DCR.  
Equation 15 gives this relationship.  
The inductor DCR is a function of the temperature and is  
approximately given by  
(EQ. 18)  
DCR(T) = DCR25C (1+ 0.00393*(T 25))  
in which 0.00393 is the temperature coefficient of the copper.  
The droop amplifier output voltage divided by the total load  
current is given by:  
(EQ. 15)  
VDCR = Io × DCR  
An R-C network senses the voltage across the inductor to  
Rdroop = G1(T)DCR(T)kdroopamp  
(EQ. 19)  
get the inductor current information. R represents the NTC  
n
network consisting of R , R  
and R . The choice of R  
par s  
R
is the actual load line slope. To make R  
droop  
ntc  
series  
droop  
will be discussed in the next section.  
independent of the inductor temperature, it is desired to  
have:  
The first step in droop load line compensation is to choose  
(EQ. 20)  
G1 (T)(1+ 0.00393*(T 25)) G1  
R and R such that the correct droop voltage appears even  
n
s
t arget  
at light loads between the VSUM and VO nodes. As a rule of  
thumb, the voltage drop across the R network, V , is set to  
where G  
is the desired ratio of V /V  
. Therefore, the  
1target  
n
DCR  
n
n
temperature characteristics G is described by:  
be 0.5-0.8 times V  
. This gain, defined as G1, provides a  
1
DCR  
fairly reasonable amount of light load signal from which to  
derive the droop voltage.  
G1  
t arget  
(EQ. 21)  
G1(T) =  
(1+ 0.00393*(T 25)  
The NTC network resistor value is dependent on the  
temperature and is given by:  
For different G1 and NTC thermistor preference, Intersil  
provides a design spreadsheet to generate the proper value  
(Rseries + Rntc )Rpar  
(EQ. 16)  
of R , R  
, R  
.
Rn (T) =  
ntc  
series  
par  
Rseries + Rntc + Rpar  
FN9251.1  
September 27, 2006  
19  
ISL6261  
R
(R in Figure 2) and R  
(R in Figure 2) sets the  
The droop capacitor refers to C in Figure 9. If C is  
n n  
drp1  
11  
drp2  
12  
droop amplifier gain, according to Equation 22:  
designed correctly, its voltage will be a high-bandwidth  
analog voltage of the inductor current. If C is not designed  
correctly, its voltage will be distorted from the actual  
waveform of the inductor current and worsen the transient  
n
Rdrp2  
kdroopamp =1+  
Rdrp1  
(EQ. 22)  
response. Figure 11 shows the transient response when C  
n
After determining R and R networks, use Equation 23 to  
s
n
is too small. V  
may sag excessively upon load  
core  
calculate the droop resistances R  
and R  
.
drp1  
drp2  
application to create a system failure. Figure 12 shows the  
transient response when C is too large. V is sluggish in  
n
core  
Rdroop  
DCRG1(25o C)  
(EQ. 23)  
Rdrp2 = (  
1)Rdrp1  
drooping to its final value. There will be excessive overshoot  
if a load occurs during this time, which may potentially hurt  
the CPU reliability.  
®
®
R
is 2.1mV/A per lntel IMVP-6 specification.  
droop  
The effectiveness of the R network is sensitive to the  
n
ΔIcore  
icore  
coupling coefficient between the NTC thermistor and the  
inductor. The NTC thermistor should be placed in close  
proximity of the inductor.  
ΔVcore  
Vcore  
To verify whether the NTC network successfully compensates  
the DCR change over temperature, one can apply full load  
current, and wait for the thermal steady state, and see how  
much the output voltage deviates from the initial voltage  
reading. Good thermal compensation can limit the drift to less  
than 2mV. If the output voltage decreases when the  
Vcore  
ΔVcore= ΔIcore×Rdroop  
FIGURE 10. DESIRED LOAD TRANSIENT RESPONSE  
WAVEFORMS  
temperature increases, that ratio between the NTC thermistor  
value and the rest of the resistor divider network has to be  
increased. Following the evaluation board value and layout of  
NTC placement will minimize the engineering time.  
icore  
Vcore  
Vcore  
The current sensing traces should be routed directly to the  
inductor pads for accurate DCR voltage drop measurement.  
However, due to layout imperfection, the calculated R  
drp2  
FIGURE 11. LOAD TRANSIENT RESPONSE WHEN Cn IS TOO  
SMALL  
may still need slight adjustment to achieve optimum load line  
slope. It is recommended to adjust R after the system  
drp2  
has achieved thermal equilibrium at full load. For example, if  
the max current is 20A, one should apply 20A load current  
and look for 42mV output voltage droop. If the voltage droop  
icore  
is 40mV, the new value of R  
is calculated by:  
dpr2  
Vcore  
Vcore  
42 mV  
Rdrp 2 _ new  
=
(Rdrp 1 + Rdrp 2 ) Rdrp 1  
40 mV  
FIGURE 12. LOAD TRANSIENT RESPONSE WHEN Cn IS TOO  
LARGE  
(EQ. 24)  
The current sensing network consists of R , R and C . The  
For the best accuracy, the effective resistance on the DFB  
and VSUM pins should be identical so that the bias current  
of the droop amplifier does not cause an offset voltage. The  
n
s
n
effective resistance is the parallel of R and R . The RC time  
n
s
constant of the current sensing network needs to match the  
L/DCR time constant of the inductor to get correct  
representation of the inductor current waveform. Equation 25  
shows this equation:  
effective resistance on the VSUM pin is the parallel of R and  
s
R , and the effective resistance on the DFB pin is the parallel  
n
of R  
and R  
.
drp2  
drp1  
Dynamic Mode of Operation – Droop Capacitor  
Design in DCR Sensing  
Figure 10 shows the desired waveforms during load  
Rn × Rs  
Rn + Rs  
L
(EQ. 25)  
=
×Cn  
DCR  
transient response. V  
needs to be as square as possible  
response is determined by several  
core  
at I  
change. The V  
core  
core  
factors, namely the choice of output inductor and output  
capacitor, the compensator design, and the droop capacitor  
design.  
FN9251.1  
September 27, 2006  
20  
ISL6261  
Solving for Cn yields  
The user can choose the actual resistor and capacitor values  
based on the recommendation and input them in the  
spreadsheet, then see the actual loop gain curves and the  
regulator output impedance curve.  
L
DCR  
Rn × Rs  
Rn + Rs  
(EQ. 26)  
Cn =  
Caution needs to be used in choosing the input resistor to  
the FB pin. Excessively high resistance will cause an error to  
the output voltage regulation due to the bias current flowing  
in the FB pin. It is recommended to keep this resistor below  
3k.  
For example: L = 0.45μH, DCR = 1.1mΩ, R = 7.68kΩ, and  
R = 3.4kΩ  
s
n
0.45μH  
0.0011  
parallel(7.68k,3.4k)  
Droop using Discrete Resistor Sensing -  
Static/Dynamic Mode of Operation  
(EQ. 27)  
Cn =  
=174nF  
Figure 3 shows a detailed schematic using discrete resistor  
sensing of the inductor current. Figure 14 shows the  
equivalent circuit. Since the current sensing resistor voltage  
Since the inductance and the DCR typically have 20% and  
7% tolerance respectively, the L/DCR time constant of each  
individual inductor may not perfectly match the RC time  
constant of the current sensing network. In mass production,  
this effect will make the transient response vary a little bit  
from board to board. Compared with potential long-term  
damage on CPU reliability, an immediate system failure is  
worse. So it is desirable to avoid the waveforms shown in  
represents the actual inductor current information, R and C  
s
n
simply provide noise filtering. The most significant noise  
comes from the ESL of the current sensing resistor. A low  
low ESL sensing resistor is strongly recommended. The  
recommended R is 100Ω and the recommended C is  
s
n
220pF. Since the current sensing resistance does not  
appreciably change with temperature, the NTC network is  
not needed for thermal compensation.  
Figure 11. It is recommended to choose the minimum C  
value based on the maximum inductance so only the  
n
scenarios of Figures 10 and 12 may happen. It should be  
Droop is designed the same way as the DCR sensing  
approach. The voltage on the current sensing resistor is  
given by the following equation:  
noted that, after calculation, fine-tuning of C value may still  
n
be needed to account for board parasitics. C also needs to  
n
be a high-grade cap like X7R with low tolerance. Another  
good option is the NPO/COG (class-I) capacitor, featuring  
only 5% tolerance and very good thermal characteristics. But  
the NPO/COG caps are only available in small capacitance  
values. In order to use such capacitors, the resistors and  
thermistors surrounding the droop voltage sensing and  
droop amplifier need to be scaled up 10X to reduce the  
capacitance by 10X. Attention needs to be paid in balancing  
the impedance of droop amplifier.  
(EQ. 28)  
Vrsen = Rsen Io  
Equation 21shows the droop amplifier gain. So the actual  
droop is given by  
Rdrp2  
Rdrp1  
(EQ. 29)  
Rdroop = Rsen 1+  
Solving for R  
yields:  
drp2  
Dynamic Mode of Operation - Compensation  
Parameters  
R
droop  
(EQ. 30)  
= 1k,  
Rdrp2 = Rdrp1  
1  
Rsen  
The voltage regulator is equivalent to a voltage source equal  
to VID in series with the output impedance. The output  
impedance needs to be 2.1mΩ in order to achieve the  
2.1mV/A load line. It is highly recommended to design the  
compensation such that the regulator output impedance is  
2.1mΩ. A type-III compensator is recommended to achieve  
the best performance. Intersil provides a spreadsheet to  
design the compensator parameters. Figure 13 shows an  
example of the spreadsheet. After the user inputs the  
parameters in the blue font, the spreadsheet will calculate  
the recommended compensator parameters (in the pink  
font), and show the loop gain curves and the regulator output  
impedance curve. The loop gain curves need to be stable for  
regulator stability, and the impedance curve needs to be  
equal to or smaller than 2.1mΩ in the entire frequency range  
to achieve good transient response.  
For example: R  
= 2.1mΩ. If R  
= 1m and R  
is 1.1k.  
droop  
sen drp1  
easy calculation gives that R  
drp2  
The current sensing traces should be routed directly to the  
current sensing resistor pads for accurate measurement.  
However, due to layout imperfections, the calculated R  
may still need slight adjustment to achieve optimum load line  
slope. It is recommended to adjust R  
drp2  
after the system  
drp2  
has achieved thermal equilibrium at full load.  
FN9251.1  
September 27, 2006  
21  
ISL6261  
FIGURE 13. AN EXAMPLE OF ISL6261 COMPENSATION SPREADSHEET  
FN9251.1  
September 27, 2006  
22  
ISL6261  
10uA  
R
ocset  
OCSET  
VO  
OC  
R
s
VSUM  
DFB  
Internal to  
ISL6261  
DROOP  
V
rsen  
DROOP  
VO  
Io Rsen  
1
FIGURE 14. EQUIVALENT MODEL FOR DROOP CIRCUIT USING DISCRETE RESISTOR SENSING  
Typical Performance (Data Taken on ISL6261 Eval1 Rev. C Evaluation Board)  
FIGURE 16. CCM LOAD LINE AND THE SPEC, VID = 1.1V,  
IN1 = 8V, VIN2 = 12.6V AND VIN3 = 19V  
FIGURE 15. CCM EFFICIENCY, VID = 1.1V,  
IN1 = 8V, VIN2 = 12.6V AND VIN3 = 19V  
V
V
FIGURE 17. DEM EFFICIENCY, VID = 0.7625V,  
VIN1 = 8V, VIN2 = 12.6V AND VIN3 = 19V  
FIGURE 18. DEM LOAD LINE AND THE SPEC, VID = 0.7625V,  
IN1 = 8V, VIN2 = 12.6V AND VIN3 = 19V  
V
FN9251.1  
September 27, 2006  
23  
ISL6261  
Typical Performance (Data Taken on ISL6261 Eval1 Rev. C Evaluation Board) (Continued)  
FIGURE 19. ENHANCED DEM EFFICIENCY, VID = 0.7625V,  
IN1 = 8V, VIN2 = 12.6V AND VIN3 = 19V  
FIGURE 20. ENHANCED DEM LOAD LINE, VID = 0.7625V,  
VIN1 = 8V, VIN2 = 12.6V AND VIN3 = 19V  
V
FIGURE 22. ENHANCED DEM LOAD LINE, VID = 1.1V,  
FIGURE 21. ENHANCED DEM EFFICIENCY, VID = 1.1V,  
IN1 = 8V, VIN2 = 12.6V AND VIN3 = 19V  
V
IN1 = 8V, VIN2 = 12.6V AND VIN3 = 19V  
V
5V/div  
0.5V/div  
10V/div  
FIGURE 23. SOFT-START, VIN = 19V, Io = 0A, VID = 1.5V,  
Ch1: VR_ON, Ch2: Vo, Ch4: PHASE  
FIGURE 24. SOFT-START, VIN = 19V, Io = 0A, VID = 1.1V,  
Ch1: VR_ON, Ch2: Vo, Ch4: PHASE  
FN9251.1  
September 27, 2006  
24  
ISL6261  
Typical Performance (Data Taken on ISL6261 Eval1 Rev. C Evaluation Board) (Continued)  
5V/div  
0.2V/div  
0.2V/div  
5V/div  
5V/div  
5V/div  
10V/div  
5V/div  
FIGURE 25. VBOOT TO VID, VIN = 19V, Io = 2A, VID = 1.5V,  
Ch1: PGD_IN, Ch2: Vo, Ch3: CLK_EN#,  
Ch4: PHASE  
FIGURE 26. VBOOT TO VID, VIN = 19V, Io = 2A, VID = 0.7625V,  
Ch1: PGD_IN, Ch2: Vo, Ch3: PGOOD,  
Ch4: CLK_EN  
5V/div  
0.5V/div  
7.5ms  
5V/div  
10V/div  
FIGURE 27. CLK_EN AND PGOOD ASSERTION DELAY,  
FIGURE 28. SHUT DOWN, VIN = 19V, Io = 0.5A, VID = 1.5V,  
Ch1: VR_ON, Ch2: Vo, Ch3: PGOOD,  
Ch4: PHASE  
V
IN=19V, Io=2A, VID=1.1V, Ch1: CLK_EN#,  
Ch2: Vo, Ch3: PGOOD, Ch4: PHASE  
FIGURE 29. SOFT START INRUSH CURRENT, VIN = 19V,  
Io = 0.5A, VID = 1.1V, Ch1: DROOP-VO  
FIGURE 30. VIN TRANSIENT TEST, VIN = 8Æ19V, Io = 2A,  
VID = 1.1V, Ch1: Vo, Ch3: VIN, Ch4: PHASE  
(2.1mV = 1A), Ch2: Vo, Ch3: Vcomp, Ch4: PHASE  
FN9251.1  
September 27, 2006  
25  
ISL6261  
Typical Performance (Data Taken on ISL6261 Eval1 Rev. C Evaluation Board) (Continued)  
FIGURE 31. C4 ENTRY/EXIT, VIN = 12.6V, Io = 0.7A,  
HFM VID = 1.1V, LFM VID = 0.9V, C4  
VID = 0.7625V, FDE = DPRSLPVR,  
Ch1: DPRSTP#, Ch2: Vo, Ch3: DPRSLPVR/FDE,  
Ch4: PHASE  
FIGURE 32. VID TOGGLING, VIN = 12.6V, Io= 0.7A,  
HFM VID = 1.1V, LFM VID = 0.9V,  
Ch1: SOFT, Ch2: Vo, Ch3: Vcomp, Ch4: PHASE  
100A/us  
50A/us  
FIGURE 33. LOAD STEP UP RESPONSE IN CCM,  
FIGURE 34. LOAD STEP DOWN RESPONSE IN CCM  
V
IN = 8V, Io = 2AÆ20A at 100A/us, VID = 1.1V,  
V
IN = 8V, Io = 20AÆ2A at 100A/us, VID = 1.1V,  
Ch1: Io, Ch2: Vo, Ch3: Vcomp, Ch4: PHASE  
Ch1: Io, Ch2: Vo, Ch3: Vcomp, Ch4: PHASE  
50A/us  
100A/us  
50A/us  
100A/us  
FIGURE 35. LOAD TRANSIENT RESPONSE IN CCM  
IN = 8V, Io = 2AÅÆ20A, VID = 1.1V,  
FIGURE 36. LOAD TRANSIENT RESPONSE IN ENHANCED  
DEM, VIN = 8V, Io = 2AÅÆ20A, VID = 1.1V,  
V
Ch1: Io, Ch2: Vo, Ch3: Vcomp, Ch4: PHASE  
Ch1: Io, Ch2: Vo, Ch3: Vcomp, Ch4: PHASE  
FN9251.1  
September 27, 2006  
26  
ISL6261  
Typical Performance (Data Taken on ISL6261 Eval1 Rev. C Evaluation Board) (Continued)  
50A/us  
100A/us  
FIGURE 37. LOAD TRANSIENT RESPONSE IN ENHANCED  
DEM, VIN = 8V, Io = 2AÅÆ20A, VID = 1.1V,  
FIGURE 38. LOAD TRANSIENT RESPONSE IN ENHANCED  
DEM, VIN = 8V, Io = 2AÅÆ20A, VID = 1.1V,  
Ch1: Io, Ch2: Vo, Ch3: Vcomp, Ch4: PHASE  
Ch1: Io, Ch2: Vo, Ch3: Vcomp, Ch4: PHASE  
120us  
FIGURE 39. OVERCURRENT PROTECTION, VIN = 12.6V,  
Io = 0AÆ28A, VID = 1.1V, Ch1: DROOP-VO  
(2.1mV = 1A), Ch2: Vo, Ch3: PGOOD,  
Ch4: PHASE  
FIGURE 40. OVERVOLTAGE (>1.7V) PROTECTION,  
V
IN = 12.6V, Io = 2A, VID = 1.1V,  
Ch2: Vo, Ch3: PGOOD, Ch4: PHASE  
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.  
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality  
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without  
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and  
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result  
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.  
For information regarding Intersil Corporation and its products, see www.intersil.com  
FN9251.1  
September 27, 2006  
27  
ISL6261  
ISL6261 Eval1 Rev. C Evaluation Board Schematic  
1 0 0  
R 4 7  
1 0 U F  
C 3 1  
1 0  
R 4 6  
1 0 K  
J 1  
R 4 2  
1 0 U F  
C 3 0  
1 0 K  
R 4 1  
1 0 K  
1 U F  
C 2 9  
1 0  
R 3 9  
R 4 0  
1 0 K  
0 . 0 1 U F  
C 2 8  
R 3 8  
1 0 K  
P 3 4  
R 3 7  
1 0 K  
R 3 6  
1 0 K  
R 3 2  
P 3 3  
P 3 1  
P 2 8  
P 2 7  
P 2 5  
P 2 4  
P 2 3  
1 U F  
C 2 7  
P 3 2  
P 2 9  
P 2 6  
0 . 2 2 U F  
C 2 6  
V I D 3  
V D D  
V S S  
V I N  
V S U M  
V O  
3 1  
2 0  
1 9  
1 8  
1 7  
1 6  
1 5  
1 3  
1 2  
V I D 4  
V I D 5  
V I D 6  
3 2  
3 3  
3 4  
3 5  
3 6  
3 7  
3 8  
3 9  
4 0  
V R _ O N  
D P R S L P V R  
D F B  
D P R S T P  
D R O O P  
P22  
1 4  
C L K _ E N  
D N P P 3 0  
R T N  
3 V 3  
V S E N  
P G O O D  
V D I F F  
1 1  
C 2 5  
D N P  
P 2 0  
P 1 9  
P 1 8  
P 1 6  
P 1 3  
P21  
R 3 1  
N T C 1 0 K  
3 . 5 7 K  
R 2 9  
4 . 5 3 K  
R 2 7  
R 2 8  
P17  
P 1 4  
P 2  
P 1 5  
P 1 1  
8 2 0 0 P F  
1
C 2 1  
D N P  
0 . 0 6 8 U F  
C 1 9  
C 1 7  
1 4 7 K  
0 . 1 2 U F  
O U T  
R 2 2  
C 1 6  
P 1  
0
1
0 . 1 U F  
C 1 5  
1 0 K  
4 9 9  
R 2 0  
R 2 1  
1 0 K  
1 0 0 0 P F  
D N P  
R 1 7  
R 1 8  
1 0 K  
1 0 0 0 P F  
C 1 1  
C 1 3  
R 1 6  
D N P  
C 1 0  
6 . 8 1 K  
R 1 4  
R 1 3  
D N P  
1 0 K  
0 . 0 1 5 U F  
R 1 0  
1 0 K  
R 1 0 3  
C 8  
R 9  
P 1 0  
P 7  
P 4  
P 5  
P 9  
P8  
P 6  
1 0 K  
R 3  
5 1 0  
1 0 U F  
C 2  
S S L _ L X A 3 0 2 5 I G C  
P 3  
R 1  
1
R E D  
G R N  
2
2 1  
2
J 9 1  
3
4 3  
2
5 1 0  
R 2  
D 3  
FN9251.1  
September 27, 2006  
28  
ISL6261  
ISL6261 Eval1 Rev. C Evaluation Board Schematic (Continued)  
2 2 U F  
C 7 0  
2 2 U F  
C 7 1  
2 2 U F  
C 6 4  
2 2 U F  
C 6 5  
2 2 U F  
C 6 6  
2 2 U F  
C 6 7  
2 2 U F  
C 6 8  
2 2 U F  
C 6 9  
2 2 U F  
C 5 8  
2 2 U F  
C 5 9  
2 2 U F  
C 6 0  
2 2 U F  
C 6 1  
2 2 U F  
C 6 2  
2 2 U F  
C 6 3  
2 2 U F  
C 5 2  
2 2 U F  
C 4 6  
2 2 U F  
C 3 6  
2 2 U F  
C 5 3  
2 2 U F  
C 4 7  
2 2 U F  
C 3 7  
2 2 U F  
C 5 4  
2 2 U F  
C 4 8  
2 2 U F  
2 2 U F  
C 5 5  
2 2 U F  
C 4 9  
2 2 U F  
C 3 9  
2 2 U F  
C 5 6  
2 2 U F  
C 5 0  
2 2 U F  
C 4 2  
2 2 U F  
C 5 7  
2 2 U F  
C 5 1  
2 2 U F  
3 3 0 U F  
C 8 9  
3 3 0 U F  
C 4 1  
3 3 0 U F  
C 4 0  
3 3 0 U F  
C 9 0  
3 3 0 U F  
C 4 4  
3 3 0 U F  
C 4 3  
C 3 8  
C 4 5  
0 . 1 U F  
C 9 1  
0 . 1 U F  
P 4 1  
C 3 5  
3
0
P 4 0  
OUT  
R 5 3  
V C C _ P R M  
0
7 . 6 8 K  
R 5 1  
P 3 9  
OUT  
R 5 0  
V S U M  
P 3 8  
P 3 7  
0 . 1 U F  
C 3 4  
5 6 U F  
3
R 8 3  
5 6 U F  
C 5 B R 8 2  
3
1 0 U F  
C 5  
1 0 U F  
D N P  
1 0 U F  
1
2
C 4  
D 2  
D N P  
R 4 9  
1 U F  
C 3 2  
D N P  
C 3 3  
P 3 5  
P 3 6  
FN9251.1  
September 27, 2006  
29  
ISL6261  
ISL6261 Eval1 Rev. C Evaluation Board Schematic (Continued)  
V S S S E N S E  
O U T  
A E 4  
A E 7  
N 2 6  
N 2 3  
VSS  
VSSSENSE  
VSS  
A E 8  
VSS  
A E 1 1  
VSS  
VSS  
A E 1 4  
N 4  
VSS  
VSS  
A E 1 6  
N 1  
M 2 5  
M 2 G2 ND_POWER  
M 5  
M 2  
L 2 4  
L 2 1  
L 6  
L 3  
K 2 6  
K 2 3  
K 4  
K 1  
VSS  
VSS  
I N  
A E 1 9  
VSS  
VSS  
A E 2 3  
VSS  
VSS  
A E 2 6  
INTEL_IMPV6  
SOCKET1  
VSS  
VSS  
A F 3  
VSS  
VSS  
A F 6  
VSS  
VSS  
A F 8  
VSS  
VSS  
A F 1 1  
VSS  
VSS  
A F 1 3  
VSS  
VSS  
A F 1 6  
VSS  
VSS  
A F 1 9  
VSS  
VSS  
A F 2 1  
VSS  
VSS  
A F 2 4  
VSS  
VSS  
W 2 2  
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
S
P 2  
P 1  
S
S
A A 6  
A A 2 1  
N 2 5  
S
A A 2 3  
N 2 4  
S
A A 2 4  
N 2 2  
S
A A 2 6  
N 5  
S
A B 2  
A B 3  
A B 5  
A B 6  
N 3  
S
S
S
S
N 2  
M 2 6  
M 2 4  
A B 2 1  
M 2 3  
S
A B 2 2  
M 4  
S
A B 2 4  
M 3  
S
A B 2 5  
M 1  
S
A C 1  
A C 2  
A C 4  
A C 5  
L 2 6  
S
S
S
S
L 2 5  
L 2 3  
L 2 2  
A C 2 0  
L 5  
S
A C 2 2  
L 4  
L 2  
L 1  
S
A C 2 3  
S
A C 2 5  
S
A C 2 6  
K 2 5  
S
A D 1  
A D 3  
A D 4  
K 2 4  
S
S
S
K 2 2  
K 5  
A D 2 0  
K 3  
K 2  
S
A D 2 1  
S
A D 2 3  
J 2 6  
S
A D 2 4  
J 2 4  
S
A E 2 1  
J 2 3  
S
A E 2 2  
J 4  
S
A E 2 4  
J 3  
S
A E 2 5  
J 1  
S
A F 1  
H 2 6  
S
A F 2 2  
H 2 5  
H 2 3  
H 2 2  
S
A F 2 3  
S
A F 2 5  
S
A F 2 6  
H 5  
H 4  
H 2  
H 1  
V I D 0  
V I D 1  
O U T  
O U T  
O U T  
O U T  
O U T  
O U T  
O U T  
A D 6  
A F 5  
A E 5  
A F 4  
A E 3  
A F 2  
A E 2  
A D 2 6  
A E 6  
V I D 0  
V I D 1  
V I D 2  
V I D 3  
V I D 4  
V I D 5  
V I D 6  
V I D 2  
V I D 3  
V I D 4  
V I D 5  
V I D 6  
G T L R E F  
G 2 5  
G 2 4  
G 2 2  
G 6  
G 5  
G 3  
G 2  
P S I  
O U T  
P S I #  
F 2 6  
INTEL_IMPV6  
SOCKET1  
FN9251.1  
September 27, 2006  
30  
ISL6261  
ISL6261 Eval1 Rev. C Evaluation Board Schematic (Continued)  
3
0 . 1 2  
R 7 6  
0 . 1  
R 7 5  
2
3
1 0 U F  
C 8 1  
J 1 1  
J 1 2  
4 9 . 9 K  
R 7 1  
3
2
FN9251.1  
September 27, 2006  
31  
ISL6261  
ISL6261 Eval1 Rev. C Evaluation Board Schematic (Continued)  
B A V 9 9  
0
R 8 0  
R 7 9  
1
D N P  
C 8 8  
3
1 X 3  
2
0
S 9  
3
1
3
2
2
1
J 7  
1 5 P F  
C 8 7  
P 4 5  
P 4 2  
P 4 4  
1 5 P F  
C 8 5  
P 4 3  
0 . 0 1 U F  
B A V 9 9  
D N P  
C 8 4  
0
0
R 7 8  
R 7 0  
1
C 7 9  
3
2
S 3  
0
D N P  
R 6 8  
R 1 0 5  
0 . 1 U F  
C 7 7  
1 0 K  
R 6 5  
1 0 K  
R 6 6  
1 0 K  
R 1 0 2  
0 . 1 U F  
C 7 5  
0 . 1 U F  
C 7 6  
1 0 K  
R 6 3  
1 0 K  
R 6 4  
1 0 K  
1 0 K  
1 0 K  
R 9 9  
R 1 0 0  
R 1 0 1  
1 0 K  
1 0 K  
1 0 K  
R 9 6  
1 0 K  
R 9 7  
1 0 K  
R 9 8  
1 0 K  
R 9 3  
R 9 4  
R 9 5  
1 0 K  
1 0 K  
1 0 K  
R 9 0  
1 0 K  
R 9 1  
1 0 K  
R 9 2  
1 0 K  
R 8 7  
R 8 8  
R 8 9  
1 0 K  
1 0 K  
1 0 K  
R 8 4  
1 0 K  
R 8 5  
1 0 K  
R 8 6  
1 0 K  
R 8 1  
R 8 2  
R 8 3  
FN9251.1  
September 27, 2006  
32  
ISL6261  
Package Outline Drawing  
L40.6x6  
40 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE  
Rev 2, 9/06  
4X  
4.5  
6.00  
0.50  
36X  
A
6
B
31  
40  
PIN #1 INDEX AREA  
6
30  
1
PIN 1  
INDEX AREA  
4 . 10 ± 0 . 15  
21  
10  
(4X)  
0.15  
11  
20  
0.10 M C A B  
TOP VIEW  
40X 0 . 4 ± 0 . 1  
4
0 . 23 +0 . 07 / -0 . 05  
BOTTOM VIEW  
SEE DETAIL "X"  
C
0.10  
C
0 . 90 ± 0 . 1  
BASE PLANE  
( 5 . 8 TYP )  
(
SEATING PLANE  
0.08 C  
SIDE VIEW  
4 . 10 )  
( 36X 0 . 5 )  
5
C
0 . 2 REF  
( 40X 0 . 23 )  
0 . 00 MIN.  
0 . 05 MAX.  
( 40X 0 . 6 )  
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 .015mm and 0.30mm from the terminal tip.  
Tiebar shown (if present) is a non-functional feature.  
5.  
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.  
FN9251.1  
September 27, 2006  
33  
ISL6261  
Package Outline Drawing  
L48.7x7  
48 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE  
Rev 3, 9/06  
4X  
5.5  
7.00  
A
44X  
6
0.50  
B
PIN #1 INDEX AREA  
37  
48  
6
1
36  
PIN 1  
INDEX AREA  
4. 30 ± 0 . 15  
12  
25  
(4X)  
0.15  
13  
24  
0.10 M C A B  
48X 0 . 40± 0 . 1  
TOP VIEW  
4
0.23 +0.07 / -0.05  
BOTTOM VIEW  
SEE DETAIL "X"  
C
C
0.10  
0 . 90 ± 0 . 1  
BASE PLANE  
( 6 . 80 TYP )  
4 . 30 )  
SEATING PLANE  
0.08 C  
(
SIDE VIEW  
( 44X 0 . 5 )  
0 . 2 REF  
5
C
( 48X 0 . 23 )  
( 48X 0 . 60 )  
0 . 00 MIN.  
0 . 05 MAX.  
TYPICAL RECOMMENDED LAND PATTERN  
DETAIL "X"  
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 .015mm and 0.30mm from the terminal tip.  
Tiebar shown (if present) is a non-functional feature.  
5.  
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.  
FN9251.1  
September 27, 2006  
34  

相关型号:

ISL6261IRZ

Single-Phase Core Regulator for IMVP-6 Mobile CPUs
INTERSIL

ISL6261IRZ-T

Single-Phase Core Regulator for IMVP-6 Mobile CPUs
INTERSIL

ISL6262

Two-Phase Core Regulator for IMVP-6 Mobile CPUs
RENESAS

ISL6262

Two-Phase Core Regulator for IMVP-6 Mobile CPUs
INTERSIL

ISL6262A

Two-Phase Core Controller Santa Rosa, IMVP-6
INTERSIL

ISL6262ACRZ

Two-Phase Core Controller Santa Rosa, IMVP-6+
INTERSIL

ISL6262ACRZ-T

Two-Phase Core Controller Santa Rosa, IMVP-6+
INTERSIL

ISL6262AIRZ

Two-Phase Core Controller Santa Rosa, IMVP-6
INTERSIL

ISL6262AIRZ-T

Two-Phase Core Controller Santa Rosa, IMVP-6+
INTERSIL

ISL6262AIRZ-T13

Dual Switching Controller
RENESAS

ISL6262AIRZ-T7

Dual Switching Controller
RENESAS

ISL6262CRZ

Two-Phase Core Regulator for IMVP-6 Mobile CPUs; QFN48; Temp Range: See Datasheet
RENESAS