Digital Power Monitor
with Clear Pin and ALERT Output
ADM1192
FUNCTIONAL BLOCK DIAGRAM
FEATURES
Powered from 3.15 V to 26 V
Precision current sense amplifier
Precision voltage input
ADM1192
SDA
V
VCC
0
12-bit ADC for current and voltage readback
ALERT output allows basic P-channel FET hot swap
up to 26 V
SETV input for setting overcurrent alert threshold
Programmable overcurrent filtering via TIMER pin
CLRB input pin
2
12-BIT
ADC
SCL
ADR
I C
I
1
A
SENSE
MUX
CURRENT
SENSE
AMPLIFIER
I2C fast mode-compliant interface (400 kHz maximum)
10-lead MSOP
ALERT
ALERT
SETV
COMPARATOR
APPLICATIONS
GND
CLRB
TIMER
Power monitoring/power budgeting
Central office equipment
Figure 1.
Telecommunications and data communications equipment
PCs/servers
3.15V TO 26V
R
SENSE
GENERAL DESCRIPTION
The ADM1192 is an integrated current sense amplifier that
offers digital current and voltage monitoring via an on-chip
12-bit analog-to-digital converter (ADC), communicated
through an I2C® interface.
VCC
SENSE
ALERT
CONTROLLER
INTERRUPT
P = VI
ADM1192
SDA
SDA
SCL
SETV
SCL
An internal current sense amplifier measures voltage across the
sense resistor in the power path via the VCC pin and the SENSE pin.
CLRB
CLRB
TIMER
ADR
GND
A 12-bit ADC can measure the current seen in the sense resistor
and in 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 four unique I2C addresses can be created,
depending on the way the ADR pin is connected.
Figure 2. Applications Diagram
The ALERT output can be used as a flag to warn a micro-
controller or field programmable gate array (FPGA) of an
overcurrent condition. ALERT outputs of multiple ADM1192
devices can be tied together and used as a combined alert.
A SETV pin is also included. A voltage applied to this pin is
internally compared with the output voltage on the current sense
amplifier. The output of the SETV comparator asserts when the
current sense amplifier output exceeds the SETV voltage. This
event is detected at the ALERT block. The ALERT block then
charges up the external TIMER capacitor with a fixed current.
When this timing cycle is complete, the ALERT output asserts.
A basic P-channel FET hot swap circuit can be implemented
with the ALERT output. The value of the TIMER capacitor
should be set so that the charging time of this capacitor is much
longer than the period during which a higher than nominal
inrush current may be flowing.
The ADM1192 is packaged in a 10-lead MSOP.
Rev. B
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