Digital Power Monitor

with Convert Pin and ALERTB Output

ADM1191

Rev. 0

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FEATURES

Powered from 3.15 V to 26 V

Precision current sense amplifier

Precision voltage input

12-bit ADC for current and voltage readback

Convert pin (CONV) for commanding an ADC read

SETV input for setting overcurrent alert threshold

ALERTB output provides an overcurrent interrupt

Two address pins allow 16 devices on the same bus

10-lead MSOP

APPLICATIONS

Power monitoring/power budgeting

Central office equipment

Telecommunication and data communication equipment

PCs/servers

GENERAL DESCRIPTION

The ADM1191 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

An internal current sense amplifier senses voltage across the sense

resistor in the power path via the VCC pin and the SENSE pin.

A 12-bit ADC can measure the current seen in the sense

resistor, as well as the supply voltage on the VCC pin.

current and voltage data from the ADC. Measurements can be

The CONV pin is especially useful for synchronizing reads on

multiple ADM1191 devices. Alternatively, the ADC can run

continuously, and the user can read the latest conversion data

created, depending on the way the A0 pin and the A1 pin are

connected.

A SETV pin is also included. A voltage applied to this pin is

internally compared to the output voltage on the current sense

amplifier. The output of the SETV comparator asserts when the

current sense amplifier ouput exceeds the SETV voltage. When

this event occurs, the ALERTB output asserts.

FUNCTIONAL BLOCK DIAGRAM

V

I

0

1

ADM1191

SENSE

SETV

VCC

CONV

MUX

ALERT

GND

COMPARATOR

CURRENT

SENSE

AMPLIFIER

A

SDA

SCL

A1

A0

ALERTB

12-BIT

ADC

Figure 1.

P = VI

CONTROLLER

ADM1191

SENSE

VCC

SDA

SCL

SDA

SCL

GND

ALERTB

CONV

CONV

A0

A1

3.15V TO 26V

SETV

INTERRUPT

Figure 2. Applications Diagram

The ALERTB output can be used as a flag to warn a micro-

controller or field programmable gate array (FPGA) of an

overcurrent condition. ALERTB outputs of multiple ADM1191

devices can be tied together and used as a combined alert.

The ADM1191 is packaged in a 10-lead MSOP.