®
ISL6556A
Data Sheet
December 29, 2004
FN9096.3
Optimized Multi-Phase PWM Controller
with 6-Bit DAC for VR10.X Application
The ISL6556A controls microprocessor core voltage
regulation by driving up to 4 synchronous-rectified buck
channels in parallel. Multi-phase buck converter architecture
uses interleaved timing to multiply channel ripple frequency
and reduce input and output ripple currents. Lower ripple
results in fewer components, lower component cost, reduced
power dissipation, and smaller implementation area.
The ISL6556A utilizes r
DS(ON)
current sensing in each
phase for adaptive voltage positioning (droop), channel-
current balancing, and overcurrent protection. To ensure
droop accuracy, an external NTC compensation circuit can
be used to completely nullify the effect of temperature
related variation in r
DS(ON)
.
A unity gain, differential amplifier is provided for remote
voltage sensing. Any potential difference between remote
and local grounds can be eliminated using the remote-sense
amplifier. The precision threshold-sensitive enable input is
available to accurately coordinate the start up of the
ISL6556A with Intersil MOSFET driver IC. Dynamic-VID™
technology allows seamless on-the-fly VID changes. The
offset pin allows accurate voltage offset settings that are
independent of VID setting. The ISL6556A uses 5V bias and
has a built-in shunt regulator to allow 12V bias using only a
small external limiting resistor.
Features
• Precision Multi-Phase Core Voltage Regulation
- Differential Remote Voltage Sensing
-
±0.5%
System Accuracy Over Temperature and Life
- Adjustable Reference-Voltage Offset
• Precision r
DS(ON)
Current Sensing
- Accurate Load-Line Programming
- Accurate Channel-Current Balancing
- Low-Cost, Lossless Current Sensing
• Internal Shunt Regulator for 5V or 12V Biasing
• Microprocessor Voltage Identification Input
- Dynamic VID™ Technology
- 6-Bit VID Input
- 0.8375V to 1.600V in 12.5mV Steps
• Threshold Enable Function for Precision Sequencing
• Overcurrent Protection
• Overvoltage Protection
- No Additional External Components Needed
- OVP Pin to drive optional Crowbar Device
• 2, 3, or 4 Phase Operation up to 1.5MHz per Phase
• QFN Package Option
- QFN Compliant to JEDEC PUB95 MO-220 QFN - Quad
Flat No Leads - Product Outline
- QFN Near Chip Scale Package Footprint; Improves
PCB Efficiency, Thinner in Profile
• Pb-free Available (RoHS Compliant)
Ordering Information
PART NUMBER*
ISL6556ACB
ISL6556ACBZ
(Note)
ISL6556ACR
ISL6556ACRZ
(Note)
TEMP. (°C)
0 to 70
0 to 70
0 to 70
0 to 70
PACKAGE
28 Ld SOIC
28 Ld SOIC
(Pb-free)
PKG. DWG. #
M28.3
M28.3
32 Ld 5x5B QFN L32.5x5B
32 Ld 5x5B QFN L32.5x5B
(Pb-free)
NOTE: Intersil Pb-free 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-020C.
*Add “-T” suffix for tape and reel.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
|
Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2002-2004. All Rights Reserved. Dynamic VID™ is a trademark of Intersil Americas Inc.
All other trademarks mentioned are the property of their respective owners.
ISL6556A
Pinouts
PGOOD
32 LEAD QFN
TOP VIEW
ENLL
GND
VID4
VCC
OVP
EN
FS
28 LEAD SOIC
TOP VIEW
OVP
PGOOD
24
23
22
21
20
19
18
17
PWM4
ISEN4
ISEN2
PWM2
PWM1
1
2
3
4
5
6
7
8
9
28
27
26
25
24
23
22
21
20
19
18
17
16
15
FS
EN
VCC
PWM4
ISEN4
ISEN2
PWM2
PWM1
ISEN1
ISEN3
PWM3
GND
RGND
VSEN
32
VID3
VID2
VID1
VID0
VID12.5
OFS
DAC
REF
1
2
3
4
5
6
7
8
9
OFSOUT
31
30
29
28
27
26
25
VID4
VID3
VID2
VID1
VID0
VID12.5
OFS
ISEN1
GND
ISEN3
DAC 10
REF 11
FB 12
COMP 13
10
FB
11
COMP
12
VDIFF
13
VSEN
14
RGND
15
GND
16
PWM3
VDIFF 14
2
ISL6556A
ISL6565ACR Block Diagram
VDIFF PGOOD
OVP
VCC
ENLL
RGND
x1
VSEN
S
OVP
LATCH
Q
R
POWER-ON
RESET (POR)
1.24V
EN
THREE-STATE
OVP
SOFT START
AND
FAULT LOGIC
CLOCK AND
SAWTOOTH
GENERATOR
FS
+200mV
∑
PWM
PWM1
OFS
OFFSET
∑
Â
PWM
PWM2
OFSOUT
REF
DAC
∑
PWM
PWM3
VID4
VID3
VID2
VID1
VID0
VID12.5
COMP
FB
OC
I_TRIP
DYNAMIC
VID
D/A
-
+
E/A
∑
PWM
PWM4
CHANNEL
CURRENT
BALANCE
CHANNEL
DETECT
ISEN1
∑
I_TOT
CHANNEL
SAMPLE
&
HOLD
CURRENT
SENSE
ISEN2
ISEN3
ISEN4
GND
3
ISL6556A
Typical Application of ISL6556ACB
+12V
VIN
VCC
PVCC
BOOT
UGATE
PHASE
HIP6601B
+5V
PWM
LGATE
GND
NTC
THERMISTOR
FB
VDIFF
VSEN
RGND
PGOOD
OVP
COMP VCC
DAC
+12V
VIN
REF
VCC
PVCC
ISEN1
BOOT
UGATE
PHASE
ISL6556ACB
VID4
VID3
VID2
VID1
VID0
VID12.5
OFS
FS
RT
GND
EN
PWM3
ISEN3
PWM4
ISEN4
+12V
PWM1
PWM2
ISEN2
HIP6601B
LGATE
PWM
GND
VIN
µ
P
LOAD
VCC
PVCC
BOOT
UGATE
PHASE
HIP6601B
LGATE
PWM
VID_PGOOD
(BUFFERED)
+12V
VIN
GND
VCC
PVCC
BOOT
UGATE
PHASE
HIP6601B
LGATE
PWM
GND
4
ISL6556A
Typical Application of ISL6556ACR
+12V
VIN
VCC
PVCC
BOOT
UGATE
PHASE
HIP6601B
+5V
PWM
LGATE
GND
NTC
THERMISTOR
FB
VDIFF
VSEN
RGND
PGOOD
OVP
COMP VCC
EN
DAC
+12V
VIN
REF
OFSOUT
VCC
PVCC
BOOT
UGATE
PHASE
ISL6556ACR
VID4
VID3
VID2
VID1
VID0
VID12.5
OFS
FS
GND ENLL
RT
ISEN1
PWM1
PWM2
ISEN2
PWM3
ISEN3
PWM4
ISEN4
EN
+12V
HIP6601B
LGATE
PWM
GND
VIN
LOAD
VCC
PVCC
BOOT
UGATE
PHASE
µ
P
HIP6601B
LGATE
PWM
VID_PGOOD
GND
+12V
VIN
VCC
PVCC
BOOT
UGATE
PHASE
HIP6601B
LGATE
PWM
GND
5
