The Analog Devices applications Bulletin
2012
HOT SWAP AND
POWER MONITORING
Contents
ADM1075: Hot Swap Controller and
Digital Power Monitor with PMBus
Interface . . . . . . . . . . . . . . . . . . . . . . . . 2
ADM1075: Applications Diagram and
Isolation Information . . . . . . . . . . . . . . . 3
ADM1075: Energy Metering . . . . . . . . . . 3
ADM1075: Evaluation Kits . . . . . . . . . . . 3
ADI Introduces the World’s Most Accurate Hot Swap Controller
with PMBus Digital Power Monitoring
The ADM1075 is a full feature, negative voltage, hot swap controller with constant power foldback that allows
boards to be safely inserted and removed from a live –48 V backplane. It features current, voltage, and power
readback, and energy metering via an integrated 12-bit analog-to-digital converter (ADC), accessed using a
PMBus interface. The part provides precise and robust current limiting and protection against both transient and
nontransient short circuits and overvoltage and undervoltage conditions.
ADM1275/ADM1276: Hot Swap
Controller and Digital Power Monitor
with PMBus Interface . . . . . . . . . . . . . . 4
ADM1175/ADM1176/ADM1177/
ADM1178: Hot Swap with I2C Digital
Power Monitoring . . . . . . . . . . . . . . . . . 6
HOT SWAP
CONTROL
TIMER
ADM1170/ADM1171/ADM1172/
ADM4210: Positive Hot Swap
Controllers . . . . . . . . . . . . . . . . . . . . . . 6
GATE
ADM4073: High-Side, Voltage Output,
Current-Sense Amplifier . . . . . . . . . . . . 7
VOUT
ADM1191/ADM1192: Digital Power
Monitors with I2C Interface . . . . . . . . . . 7
CAPTURED POWER
USAGE DATA
IIN
INRUSH
CURRENT
IS LIMITED
VOLTAGE
CURRENT
FET
POWER
POWER
Selection Tables . . . . . . . . . . . . . . . . . . 8
POWER (W)
ADM1075
Infrastructure for the evolving datacenter.
www.analog.com/power
SYSTEM
LOAD
W
00750.0
ENERGY (kWh)
–48 V RTN
–48 V
PMBUS
MICROPROCESSOR
kWh
07753.0
RSENSE
Switches and routers for carrier, access,
enterprise networks.
Pluggable subsystems and modules.
ADM1075: Hot Swap Controller and Digital Power Monitor with PMBus Interface
The ADM1075 is a full feature, negative voltage, hot swap controller with constant power foldback that allows boards to be safely inserted and removed from
a live –48 V backplane. It also features current, voltage, power readback, and energy metering via an integrated 12-bit analog-to-digital converter (ADC),
accessed using a PMBus interface.
Shunt resistor: flexible
operating range.
Supply good active
low when input
within programmed
voltage window.
SHDN: level triggered
shutdown of hot swap.
RESTART: falling edge
triggered 10 sec restart.
12-bit ADC ±1%
accurate for current,
voltage and power
readback.
PMBus (I2C) interface.
General-purpose output pins.
–48V RTN (0V)
RDROP
Separate UVH/UVL
pins for accurate
hysteresis settings.
V CC AND
REFERENCE
GENERATOR
VEE
UVH
UVL
OV
High accuracy
1% UVH, UVL, OV
thresholds.
SHDN RESTART
POWER
ACCUMULATOR
DIGITAL
AND
PMBUS
POWER
MULTIPLIER
UNDERVOLTAGE
AND
OVERVOLTAGE
DETECTOR
Power-good output
determined from drain
and gate voltages.
LATCH
GPO1
GPO2
SDAO
SDAI
SCL
ADR
12-BIT ADC
PLIM: resistor divider sets
constant power foldback.
ADC_AUX
ADC_V
PWRGD
FET POWER
FOLDBACK
CONTROL
Two separate ADC
inputs for voltage
monitoring.
VCAP
DRAIN
PLIM
FAULT TIMER
ISET
VEE
GATE CONTROL
GATE
CURRENT LIMIT
SENSE+
GATE pin: responds to short
circuits within 370 ns.
N-FET
RSENSE
High gate drive (12 V) à
lowest RDSon when FET
fully enhanced.
SENSE-
ISET: resistor
adjustable
current limit.
High accuracy
current limit
(2%) allows for
tighter FET SOA
protection.
SPLYGD
V IN
TIMER
SS
VEE_G
Rsense: low insertion loss
15 mV to 25 mV ADM1075-1
30 mV to 50 mV ADM1075-2.
VEE
–48V
TIMER cap: sets time,
FET remains on while
current in regulation.
SS cap: sets soft
start current profile.
Separate ground pin
for gate pull-down
return.
Separate VEE and SENSE—
ensures minimal voltage drop in
sense trace.
Hot Swap and E-Fuse Applications
• Telecommunications and data communication equipment
• Central office switching
• Optical networks
• High availability servers
• –48 V distributed power systems
• Negative power supply control
7
Features
• The ADM1075 features best-in-class current-sense accuracy (±0.7%)
6
• Constant power foldback for improved FET SOA protection
• Resistor-programmable current limit
• 5 mV to 25 mV for ADM1075-1
• 10 mV to 50 mV for ADM1075-2
• ±1% accurate, 12-bit ADC for current, VIN/VAUX readback
• Suitable for wide input range due to internal shunt regulator
5
ACCURACY (%)
• Response time to short circuit <1 µs
ADM1075-1
4
3
ADM1075-2
2
1
• High gate drive voltage to ensure lowest RDSON
• Fault recording with latched status register
• 28-lead LFCSP and 28-lead TSSOP
| Hot Swap and Power Monitoring
2
0
0
10
20
30
40
SENSE VOLTAGE (mV)
50
60
ADM1075: Applications Diagram and Isolation Information
Isolation is usually required between the –48 V backplane and
any microcontroller communicating with the ADM1075 device.
RTN
The ADuM1250 is an ideal companion device for I2C isolation.
The ADuM1250 is an I2C isolator based on iCoupler® chip scale
transformer technology from Analog Devices.
ADP1046
ISOLATED DIGITAL
DC-TO-DC BRICK
–48V
There are also other iCoupler devices available if isolation of
other digital signals is required, for example, the ADuM5402,
which also provides an integrated isolated dc-to-dc converter.
3.3V MANAGEMENT BUS
–48V
ADM1075: Energy Metering
ADM1075
–48V HOT SWAP AND
DIGITAL POWER MONITOR
SDA_ISO
ADuM1250
SDA
SCL_ISO
I2C
SCL
ISOLATOR
PROCESSOR
A PMBus interface allows a controller to read current, voltage,
and power from the ADC. The ADC_V input voltage and Iout
current measurement values are multiplied by the ADM1075
to give the input power value. There is also an energy accumulator register—each time a power calculation is done, the power value is added to the
energy accumulator register. This allows for the calculation of average power as well as instantaneous power measurements.
ADM1075
ADC_V
ADM1075
VOLTAGE
RSENSE
ADC
𝛍P
𝚫ENERGY
POWER
VOLTAGE
CURRENT
POWER
ENERGY
CURRENT
VOLTAGE
÷
kWh
𝚫
ENERGY
ADM1075: Evaluation Kits
The ADM1075 full feature evaluation board can be purchased on the ADM1075 Web page along with the serial I/O interface connector required to
communicate with the evaluation board. The connector enables communication between the I2C port on the evaluation board and the evaluation software
via the USB port on a PC. All relevant documentation and details can be found on the ADM1075 product page www.analog.com/ADM1075.
ADM1075 evaluation software.
Evaluation kits available.
www.analog.com/power | 3
ADM1275/ADM1276: Hot Swap Controller and Digital Power Monitor with PMBus Interface
RSENSE: measure system current. Hot swap control and fault protection.
Adjust current limit to allow for standard sense resistor value.
Q1: current through sense resistor
limited by controlling gate of FET.
Low insertion loss (5 mV to 25 mV).
RSENSE
2V TO 20V
UV/OV pins: FET
gate pulled low if
under/overvoltage
detected.
2.95V
TO
20V
SENSE+
VCAP
ISET: resistor
adjustable
current limit.
OV
IOUT
+
1.0V –
–
1.0V +
REF
SELECT
1.0V
SS
GATE
DRIVE/
LOGIC
TIMER
SENSE+
VOUT
IOUT
SS cap: sets inrush
current profile.
GATE
VOUT
TIMEOUT
CURRENT
LIMIT
TIMER
ON
+
–
CURRENT
LIMIT
CONTROL
VCBOS
TIMER
ON
TIMER
GATE pin: responds to short
circuit within 370 ns.
CHARGE
PUMP
VCP
LDO
ISET
Current limit control:
high accuracy current
limit (2%) à tighter
FET SOA protection.
SENSE–
+ – ADM1275/ADM1276
×50
VCC
UV
Q1
FLB
TIMEOUT
12-BIT
ADC
LOGIC
AND
PMBUS
PWRGD
GPO1/ALERT1/CONV
GPO2 /ALERT2
LATCH
SCL
SDA
ADR
GND
TIMER cap: sets time, FET remains
on while current in regulation.
ADM1275/ADM1276 evaluation software.
| Hot Swap and Power Monitoring
4
12-bit ADC: ±1% accurate ADC for
current, voltage, and power readback.
Evaluation kits available.
Gate drive/logic block: high
gate drive à lowest RDSON
when FET fully enhanced.
Current levels à ability
to drive multiple FETs to
share current.
FLB pin: actively lowers
the current limit as voltage
across FET increases à
tighter FET SOA protection.
ADM1276—energy metering.
Power Monitoring and Energy Metering
A PMBus interface allows a controller to read current, voltage (ADM1275/ADM1276), and power (ADM1276 only) from the ADC. The VIN input voltage
and Iout current measurement values are multiplied by the ADM1276 to give the input power value. There is also an energy accumulator register — each
time a power calculation is done, the power value is added to the energy accumulator register. This allows for the calculation of average power, as well as
instantaneous power measurements.
RSENSE
POWER (W)
ADM1276
PMBUS
SYSTEM
LOAD
W
00750.0
ENERGY (kWh)
+12V
MICROPROCESSOR
kWh
07753.0
GND
Evaluation kits available.
ADM1275
ADM1275/ADM1276
ADM1276
VOLTAGE
VOLTAGE
RSENSE
ADC
CURRENT
VOLTAGE
CURRENT
𝛍P
ADM1276
POWER
VOLTAGE
POWER
CURRENT
ENERGY
𝚫ENERGY
VOLTAGE
÷
ENERGY
kWh
𝚫
Hot Swap and E-Fuse Applications
• Servers
• Power monitoring and control/power budgeting
• Base stations
• Telecommunications and data communication equipment
• Line cards
• Central office equipment
Features
• The ADM1275/ADM1276 feature best-in-class current-sense
accuracy (±0.7%)
5
• High accuracy over a wide sense voltage range ensures more
accurate measurements at normal operating levels
• 370 ns response time to short circuit
• Resistor-programmable 5 mV to 25 mV current limit
• ±1% accurate, 12-bit ADC for current, VIN /VOUT readback
ACCURACY (%)
• Controls supply voltages from 2 V to 20 V
128× AVERAGING
VIN = 12V, –40ºC TO +85ºC
4
3
2
• Charge-pumped gate drive for multiple external N-channel FETs
• High gate drive voltage to ensure lowest RDSON
1
• Foldback for tighter FET SOA protection
• PMBus fast mode compliant interface
• 16-lead QSOP and 20-lead QSOP/LFCSP
0
0
10
20
30
CURRENT-SENSE VOLTAGE (mV)
www.analog.com/power | 5
ADM1175/ADM1176/ADM1177/ADM1178: Hot Swap with I2C Digital Power Monitoring
The ADM1175/ADM1176/ADM1177/ADM1178 are a series of integrated hot swap controllers and current-sense amplifiers that offer digital current and
voltage monitoring via an on-chip 12-bit analog-to-digital converter (ADC), communicated through an I2C interface.
Features
• Controls supply voltages from 3.15 V to 16.5 V
• Manual convert pin: ADM1175
CONV
ADM1175
• Additional address pin: ADM1176
MUX
V
VCC
• Soft start pin: ADM1177
• Overcurrent alert pin: ADM1178
I
A
• ±3% accurate hot swap current limit level
SDA
0
12-BIT
ADC
1
I2C
SENSE
SCL
ADR
CURRENTSENSE
AMPLIFIER
• 12-bit ADC for current and voltage readback
• Charge pumped gate drive for N-channel FET
FET DRIVE
CONTROLLER
ON
• Adjustable current limit with circuit breaker
GATE
1.3V
• Automatic retry (-1 model) or latch-off (-2 model)
on current fault
• I2C fast mode-compliant interface
UV COMPARATOR
TIMER
GND
• 10-lead MSOP
HOT SWAP CONTROL
VIN = 12V
RSENSE
LONG
Q1
CLOAD
VCC
SENSE
GATE
CONTROLLER
WATTS
ADM1177
SHORT RON1
ON
CSS
TIMER
RON2
GND
LONG
GND
CTIMER
𝛍P
SDA
SCL
SS
ADR
GND
VOLTAGE
CURRENT
VOLTAGE
ADM1170/ADM1171/ADM1172/ADM4210: Positive Hot Swap Controllers
The ADM1170/ADM1171/ADM1172/ADM4210 are a series of low voltage, positive, high-side, hot swap controllers that safely enable a printed circuit
board to be removed from and inserted into a live backplane. This is achieved using an external N-channel power MOSFET with a current control loop
that monitors the load current through a sense resistor. An internal charge pump is used to enhance the gate of an N-channel FET.
Features
VIN = 12V
RSENSE
LONG
Q1
VOUT = 12V
• Separate VCC pin, soft start pin— ADM1170
CLOAD
• Current-sense output, soft start pin — ADM1171
VCC
SHORT
• Power fail detector — ADM1172
RON1
• Controls supply rails from 1.6 V to 16.5 V
RON2
TIMER
• Charge pumped gate drive for external N-channel FET
• 8-lead TSOT (ADM117x)/6-lead TSOT (ADM4210)
| Hot Swap and Power Monitoring
6
RPR1
GATE
ADM1172
PFI
• 50 mV sense voltage limit providing minimal voltage
drop losses
• Automatic retry (-1 model) or latch-off (-2 model)
SENSE
ON
GND
LONG
PFO
GND
CTIMER
GND
𝛍P
RPR2
ADM4073: High-Side, Voltage Output, Current-Sense Amplifier
The ADM4073 is a low cost, high-side, current-sense amplifier ideal for small portable applications. The device is available in three different gain models.
The voltage on the output pin is determined by the current flowing through the selectable external sense resistor and the gain of the version selected.
Features
• Low cost, compact current-sense solution
ILOAD
RSENSE
2V TO 28V
• Three available gain versions (20/50/100)
• Typical ±1.0% full-scale accuracy
VCC
3V TO 28V
VOUT
RS–
RS+
IRG1
RG1
RG2
0.1𝛍F
• Wide 1.8 MHz bandwidth
AV
• 3 V to 28 V operating supply
• Wide 2 V to 28 V common-mode range;
operates from −40°C to +125°C
OUT
CURRENT
MIRROR
• Available in a 6-lead SOT-23 package
IRGD
RGD = 12k𝛀
ADM4073
GND
ADM1191/ADM1192: Digital Power Monitors with I2C Interface
The ADM1191 and ADM1192 are integrated current-sense amplifiers that offer digital current and voltage monitoring via an on-chip 12-bit
analog-to-digital converter (ADC), communicated through an I2C interface.
Features
• Sensing from 3.15 V to 26 V
CONV
ADM1191
• ±1.5% current-sense accuracy
• 12-bit ADC for current and voltage readback
V
VCC
• ALERTB output for overcurrent interrupts
• I2C fast mode-compliant interface
A
SENSE
• Up to 16 devices on the same bus
I
CURRENTSENSE
AMPLIFIER
• 10-lead MSOP
• CONV, A1/A0, ALERTB—ADM1191
SDA
0
12-BIT
ADC
1
I2C
A1
A0
MUX
SETV
ALERT
• TIMER, CLRB, ALERT—ADM1192
SCL
ALERTB
COMPARATOR
GND
3.15V TO 26V
RSENSE
VCC
SENSE
ADM1192
SDA
SCL
SETV
RON2
CONTROLLER
WATTS
𝛍P
ALERT
CLRB
TIMER
GND
CTIMER
ADR
GND
VOLTAGE
CURRENT
VOLTAGE
www.analog.com/power | 7
Low Voltage Positive Hot Swap Controllers with Digital Power Monitor
Voltage
Range (V)
Undervoltage
Detection/Overvoltage
Detection
Digital V and I
Readback
Additional Features
Package
Price ($U.S.)1
ADM1175
3.15 to 16.5
ON pin (UV);
ON pin (OV)
I2C interface with
four addresses
Convert pin
10-lead MSOP
2.53
ADM1176
3.15 to 16.5
ON pin (UV)
I2C interface with
16 addresses
—
10-lead MSOP
2.53
ADM1177
3.15 to 16.5
ON pin (UV)
I2C interface with
four addresses
Soft start
10-lead MSOP
2.53
ADM1178
3.15 to 16.5
ON pin (UV)
I2C interface with
four addresses
ALERTB pin
10-lead MSOP
2.73
ADM1275 New
2 to 20
UV pin, OV pin
PMBus interface with
four addresses
Soft start, foldback, fast gate
shutdown, adjustable currentsense limit
16-lead QSOP,
20-lead QSOP,
20-lead LFCSP
4.49
4.99
4.99
ADM1276 New
2 to 20
UV pin, OV pin
PMBus interface with
four addresses; also
power readback
Soft start, foldback, fast gate
shutdown, adjustable currentsense limit
20-lead LFCSP
5.29
Part Number
Low Voltage Positive Hot Swap Controllers
Part Number
Voltage
Range (V)
Undervoltage
Detection/Overvoltage
Detection
Additional Features
Package
Price ($U.S.)1
ADM1170
1.6 to 16.5
ON pin (UV)
Soft start, separate
VCC pin
8-lead TSOT
2.13
ADM1171
2.7 to 16.5
ON pin (UV)
Soft start, current-sense
output
8-lead TSOT
2.23
ADM1172
2.7 to 16.5
ON pin (UV)
Power fail detector
8-lead TSOT
2.02
ADM4210
2.7 to 16.5
ON pin (UV)
—
6-lead TSOT
1.99
Analog Devices, Inc.
Worldwide Headquarters
Analog Devices, Inc.
One Technology Way
P.O. Box 9106
Norwood, MA 02062-9106
U.S.A.
Tel: 781.329.4700
(800.262.5643,
U.S.A. only)
Fax: 781.461.3113
–48 V Hot Swap Controllers
Part Number
Voltage
Range (V)
Undervoltage
Detection/Overvoltage
Detection
Digital V and I
Readback
Additional Features
Package
Price ($U.S.)1
ADM1070
Shunt
regulated
UV/OV pin
—
—
6-lead SOT-23
1.57
ADM1073
Shunt
regulated
UV pin, OV pin
—
Soft start, drain pin monitoring,
additional I/Os
14-lead TSSOP
2.13
UVH pin, UVL pin, OV pin
PMBus interface with
four addresses; also
power readback
Soft start, constant power
foldback, fast gate shutdown,
adjustable current-sense limit
28-lead LFCSP,
28-lead TSSOP
4.99
ADM1075
New
Shunt
regulated
Digital Power Monitors
Part Number
Voltage
Range (V)
Overcurrent
Timer
Digital V and I Readback
Additional Features
Package
Price
($U.S.)1
ADM1191
3.15 to 26
—
I2C interface with 16 addresses
Programmable alert output,
convert pin
10-lead MSOP
1.92
ADM1192
3.15 to 26
Capacitor
programmable
I2C interface with four addresses
Programmable alert output,
timer CLR pin
10-lead MSOP
1.92
Current-Sense Amplifiers — High Side
Part Number
ADM4073T
CM Range (V)
Gain
Max Sense
Voltage (mV)
2 to 28
20
150
Supply
Range (V)
Accuracy (Typ)
Package
Price
($U.S.)1
3 to 28
1%
6-lead SOT-23
0.99
ADM4073F
2 to 28
50
150
3 to 28
1%
6-lead SOT-23
0.99
ADM4073H
2 to 28
100
150
3 to 28
1%
6-lead SOT-23
0.99
All prices are in USD in quantities greater than 1000.
1
All prices in this bulletin are in USD in quantities
greater than 1000 (unless otherwise noted),
recommended lowest grade resale, FOB U.S.A.
I2C refers to a communications protocol
originally developed by Philips Semiconductors
(now NXP Semiconductors).
©2012 Analog Devices, Inc. All rights reserved.
Trademarks and registered trademarks are the
property of their respective owners.
Printed in the U.S.A.
B02939-1-8/12(E)
www.analog.com/power
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Germany
Tel: 49.89.76903.0
Fax: 49.89.76903.157
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Headquarters
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Tel: 86.21.2320.8000
Fax: 86.21.2320.8222