DATASHEET
ISL8271M
Digital DC/DC PMBus 33A Module
The
ISL8271M
is a 33A step-down DC/DC power supply module
with an integrated digital PWM controller, synchronous power
switches, an inductor, and passives. Only bulk input and output
capacitors are needed to finish the design. The 33A of
continuous output current can be delivered without the need
for airflow or a heatsink. The thermally enhanced HDA module
is capable of dissipating heat directly into the PCB.
The ISL8271M uses ChargeMode™ control architecture, which
responds to a transient load within a single switching cycle.
The ISL8271M comes with a preprogrammed configuration for
operating in a pin-strap mode: the output voltage, switching
frequency, and the device SMBus address can be programmed
with external resistors. Other configuration options, such as
soft-start and fault limits can be programmed or changed
using the PMBus compliant serial bus interface. PMBus can be
used to monitor voltages, current, temperatures, and fault
status. The ISL8271M is supported by PowerNavigator™
software, a Graphical User Interface (GUI) that can be used to
configure modules to a desired solution.
The ISL8271M is available in a 40 Ld compact 17mmx19mm
HDA module with very low profile height of 3.55mm, suitable
for automated assembly by standard surface mount
equipment. The ISL8271M is RoHS compliant by exemption.
FN8636
Rev.4.00
Aug 17, 2017
Features
• Complete digital switch mode power supply
- Wide V
IN
range: 4.5V to 14V
- Programmable V
OUT
range: 0.6V to 5V
• PMBus compliant I
2
C communication interface
- Programmable V
OUT
, margining, UV/OV, I
OUT
limit,
soft-start/stop, sequencing, and external synchronization
- Monitor: V
IN
, V
OUT
, I
OUT
, temperature, duty cycle,
switching frequency, and faults
• ChargeMode control architecture
• ±1.0% V
OUT
accuracy over line, load, and temperature
• Power-good indicator
• Over-temperature protection
• Internal nonvolatile memory and fault logging
• Patented thermally enhanced HDA package
• Intuitive configuration using
PowerNavigator
Applications
• Server, telecom, storage, and datacom
• Industrial/ATE and networking equipment
• General purpose power for ASIC, FPGA, DSP, and memory
Related Literature
• For a full list of related documents, visit our website
-
ISL8271M
product page
V
IN
C
IN
2.2
V
IN
V
DD
V
OUT
V
SEN+
V
SEN-
V
OUT
C
OUT
m
19
m
17m
m
ISL8271M
V
DRVOUT
SCL
SDA
SALRT
PMBUS
INTERFACE
V
DRVIN
1µ
10µ
3.55mm
SGND
PGND
NOTE:
1. Only bulk input and output capacitors are required to finish the design.
FIGURE 1. A COMPLETE DIGITAL SWITCH MODE POWER SUPPLY
FIGURE 2. A SMALL PACKAGE FOR HIGH POWER DENSITY
FN8636 Rev.4.00
Aug 17, 2017
Page 1 of 57
ISL8271M
Table of Contents
Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pin Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin Descriptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
ISL8271M Internal Block Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Recommended Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Typical Performance Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Efficiency Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transient Response Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Derating Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Derating Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMBus Communications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Voltage Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Soft-Start Delay and Ramp Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power-Good . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Switching Frequency and PLL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loop Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Undervoltage Lockout (UVLO). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SMBus Module Address Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Overvoltage Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Prebias Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Overload Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Digital-DC Bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Phase Spreading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Sequencing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fault Spreading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature Monitoring Using XTEMP Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Monitoring Using SMBus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Snapshot Parameter Capture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nonvolatile Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Package Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PCB Layout Pattern Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Vias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stencil Pattern Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reflow Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10
10
11
12
13
16
16
16
16
17
17
17
17
18
18
18
19
19
19
19
19
20
20
20
20
20
22
22
22
22
22
22
Typical Application Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
PCB Layout Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
PMBus Command Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
PMBus Data Formats. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
PMBus Use Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
PMBus Command Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Revision History. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Firmware Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
About Intersil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
FN8636 Rev.4.00
Aug 17, 2017
Page 2 of 57
ISL8271M
Ordering Information
PART NUMBER
(Notes
2, 3, 4)
ISL8271MAIRZ
ISL8271MBIRZ
ISL8271MEVAL1Z
NOTES:
2. Add “-T” suffix for a 500 unit Tape and Reel option. Refer to
TB347
for details on reel specifications.
3. These Intersil Pb-free plastic packaged products are RoHS compliant by EU exemption 7C-I and 7A. They employ special Pb-free material sets; molding
compounds/die attach materials and NiPdAu plate-e4 termination finish, which is 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.
4. For Moisture Sensitivity Level (MSL), see the product information page for
ISL8271M.
For more information on MSL, see
TB363.
5. See
“Firmware Revision History” on page 50;
only the latest firmware revision is recommended for new designs.
PART MARKING
ISL8271M
ISL8271MB
Evaluation board
FIRMWARE
REVISION
(Note
5)
FC01
FC02
TEMP RANGE
(°C)
-40 to +85
-40 to +85
PACKAGE
(RoHS Compliant)
40 Ld 17x19 HDA
40 Ld 17x19 HDA
PKG.
DWG. #
Y40.17x19
Y40.17x19
ISL
INTERSIL DEVICE DESIGNATOR
BASE PART NUMBER
FIRMWARE REVISION
A: FC01
B: FC02
xxxxM
F
T
R
Z
S
SHIPPING OPTION
BLANK: BULK
T: TAPE AND REEL
ROHS
Z: ROHS COMPLIANT
OPERATING TEMPERATURE
I: INDUSTRIAL (‐ 40°C TO +85°C)
PACKAGE DESIGNATOR
R: HIGH DENSITY ARRAY (HDA)
FN8636 Rev.4.00
Aug 17, 2017
Page 3 of 57
ISL8271M
Pin Configuration
ISL8271M
(40 LD HDA)
TOP VIEW
SALRT
SGND
PGND
VSET
MGN
SDA
SCL
VDD
16
38
37
15
7
8
36
SGND
VR5
35
VOUT 14
NC
NC
SA
DDC
X
TEMP+
X
TEMP -
NC
NC
V
SEN+
V
SEN -
V
DRVOUT
1
2
3
4
5
6
27
26
28 PG
29 UVLO
25
24
23
22
21
20
19
18
SYNC 39
V25
40
VDDC
SGND
PGND
9
30
PHASE
34
PGND
V
DRVIN
10
33
VIN
11
31
PGND
NC
32
NC
PGND
12
VSWH
13
Pin Descriptions
PIN
1
LABEL
DDC
TYPE
I/O
DESCRIPTION
A Digital-DC™ bus. This dedicated bus provides the communication channel between devices for features such as
sequencing and fault spreading. The DDC pin on all Digital-DC devices should be connected together. A pull-up resistor
is required for this application.
Differential external temperature sensor positive input pin.
Differential external temperature sensor negative input pin.
Differential Output voltage sense feedback. Connect to positive output regulation point.
Differential Output voltage sense feedback. Connect to negative output regulation point.
Output of internal LDO for powering internal gate driver block. Place a 10µF ceramic capacitor at this pin. LDO output
is dedicated to powering internal gate driver stage only. Do not use this LDO for any other purpose.
Power ground. Refer to the
“PCB Layout Guidelines” on page 21
for the PGND pad connections and decoupling
capacitors placement.
2
3
6
7
8
9, 12, 23,
31, 34
X
TEMP+
X
TEMP-
V
SEN+
V
SEN-
V
DRVOUT
PGND
I
I
I
I
PWR
PWR
FN8636 Rev.4.00
Aug 17, 2017
EN
17
VR6
Page 4 of 57
ISL8271M
Pin Descriptions
PIN
10
11
13
14
15, 27,
40
16
17
18
19
20
21
24
LABEL
V
DRVIN
VIN
VSWH
VOUT
SGND
VDD
EN
SCL
SDA
SALRT
SA
MGN
TYPE
PWR
PWR
PWR
PWR
PWR
PWR
I
I
I/O
O
I
I
(Continued)
DESCRIPTION
Input supply to the internal LDO for powering the internal gate driver block. An RC filter is required if VIN supply is
shared. Refer to the
“PCB Layout Guidelines” on page 21.
Main input supply. Refer to the“PCB
Layout Guidelines” on page 21
for the decoupling capacitors placement from VIN
to PGND.
Switch node. Refer to the
“PCB Layout Guidelines” on page 21
for connecting VSWH pads to electrically isolated PCB
copper island to dissipate internal heat.
Power supply output. Range: 0.6V to 5V. Refer to
“Derating Curves” on page 12
for maximum recommended output
current at various output voltages.
Controller Signal ground. Refer to the
“PCB Layout Guidelines” on page 21
for the SGND pad connections.
Input supply to digital controller. Connect the VDD pad to the VIN supply. Refer to the
“PCB Layout Guidelines” on
page 21
for the decoupling capacitors placement from VDD to SGND.
External enable input. Logic high enables the module.
Serial clock input. A pull-up resistor is required for this application.
Serial data. A pull-up resistor is required for this application.
Serial alert. A pull-up resistor is required for this application.
Serial bus address select pin. Refer to
Table 6
for list of resistor values to set various serial bus address.
External VOUT margin control pin. Active high (>2V) signal at this pin sets V
OUT
margin high, Active low (<0.8V) sets
V
OUT
margin low and high impedance (float) will bring V
OUT
back to nominal voltage. The factory default range for
margining is nominal V
OUT
±5%. When using PMBus to control margin command, leave this pin as no connect.
Output voltage selection pin. Refer to
Table 3
for list of resistor values to set various output voltages.
Power-good output. Power-good output can be open drain that requires pull-up resistor or push-pull output that can
drive a logic input.
VDD undervoltage lockout selection. Refer to
Table 5
for list of resistors value to set various UVLO levels.
Switch node pad for DCR sensing. Electrically shorted inside to VSWH but for higher current sensing accuracy connect
PHASE pad to VSWH pad externally. Refer to the
“PCB Layout Guidelines” on page 21.
6V Internal reference supply voltage.
5V Internal reference supply voltage.
VDD Clean. Noise at the VDD pin is filtered with ferrite bead and capacitor. For V
DD
> 6V, leave this pin as no connect.
For 5.5
V
DD
6V, connect the VDDC pin to the VR6 pin. For 4.5
VDD < 5.5V, connect the VDDC pin to the VR6 and
VR5 pin.
2.5V internal reference supply voltage.
The SYNC pin can be input to an external clock for frequency synchronization or output to supply a clock signal to
other modules for synchronization. Refer to
Table 4
for list of resistor values to program various switching
frequencies.
Test pins. These pins are not electrically isolated. Leave these pins as no connect.
25
28
29
30
35
36
37
VSET
PG
UVLO
PHASE
VR6
VR5
VDDC
I
O
I
PWR
PWR
PWR
PWR
38
39
V25
SYNC
PWR
I/O
4, 5, 22,
26, 32,
33
NC
FN8636 Rev.4.00
Aug 17, 2017
Page 5 of 57
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