ADM1177-1ARMZ-R7(RevPrD) Просмотр технического описания (PDF) - Analog Devices
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ADM1177-1ARMZ-R7
(Rev.:RevPrD)
(Rev.:RevPrD)
Analog Devices
ADM1177-1ARMZ-R7 Datasheet PDF : 16 Pages
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Hot Swap Controller and
Digital Power Monitor with Soft-Start Pin
Preliminary Technical Data
ADM1177
FEATURES
Allows Safe Board Insertion and Removal from a Live
Backplane
Controls Supply Voltages from 3.15 V to 14V
Precision Current Sense Amplifier
Precision Voltage Input
12-Bit ADC for Current and Voltage Readback
Charge Pumped Gate Drive for External N-FET Switch
Adjustable Analog Current Limit with Circuit Breaker
Fast Response Limits Peak Fault Current
Automatic Retry or Latch-Off On Current Fault
Programmable hot swap timing via TIMER pin
Soft-start pin for reference adjustment and programming of
initial current ramp rate
Active-high ON pin
I2C Fast Mode compliant interface (400 KHz max)
10-lead MSOP package
APPLICATIONS
Power Monitoring/Power Budgeting
Central office Equipment
Telecommunication and Datacommunication Equipment
PC/Servers
GENERAL DESCRIPTION
The ADM1177 is an integrated hot-swap controller which offers
digital current and voltage monitoring via an on-chip 12-bit
ADC, communicated through an I2C interface.
An internal current sense amplifier senses voltage across the
sense resistor in the power path via the VCC and SENSE pins.
The ADM1177 limits the current through this resistor by
controlling the gate voltage of an external N-channel FET in the
power path, via the GATE pin. The sense voltage (and hence the
inrush current) is kept below a preset maximum.
The ADM1177 protects the external FET by limiting the time
that it spends with the maximum current running in it. This
current limit period is set by the choice of capacitor attached to
the TIMER pin. Additionally, the device provides protection
from overcurrent events at times after the hot-swap event is
complete. In the case of a short-circuit event the current in the
sense resistor will exceed an overcurrent trip threshold, and the
FET will be switched off immediately by pulling down the
GATE pin.
Rev. PrD May 2006
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
FUNCTIONAL BLOCK DIAGRAM
VCC
SENSE
ADM1177
Mux
V
0
+
A
-
I
1
Current Sense
Amplifier
12-Bit
ADC
SDA
I2C
SCL
ADR
ON
+
1.3V -
UV Comparator
FET Drive
Controller
GND
SS TIMER
Figure 1.
APPLICATIONS DIAGRAM
3.15V - 14V
RSENSE
N-Channel FET
GATE
VCC SENSE
GATE
ADM1177
ON
SDA
SCL
SS
TIMER
GND ADR
CONTROLLER
SDA
SCL P=VI
Figure 2.
A Soft-start (SS) pin is also included. This gives the user control
over the reference on the current sense amplifier. An internal
current source will charge a capacitor on this pin at startup,
allowing the user set the profile of the initial current ramp. A
voltage can also be driven on this pin to alter the reference.
A 12-bit ADC can measure the current seen in the sense
resistor, and also the supply voltage on the VCC pin.
An industry standard I2C interface allows a controller to read
current and voltage data from the ADC. Measurements can be
initiated by an I2C command. Alternatively the ADC can run
continuously and the user can read the latest conversion data
whenever it is required. Up to 4 unique I2C addresses can be
created by the way the ADR pin is connected.
The ADM1177 is packaged in a 10-lead MSOP package.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
© 2006 Analog Devices, Inc. All rights reserved.
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