Datasheet

ManualsBrandsANALOG DEVICES ManualsPMICsPMIC - power management - special purpose 1.7 mA MSOP 10

Digital Power Monitor

with Convert Pin and ALERTB Output

Data Sheet

ADM1191

Rev. C

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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 (CONV) pin for commanding an ADC read

SETV input for setting overcurrent alert threshold

ALERTB output provides an overcurrent interrupt

C fast mode-compliant interface (400 kHz maximum)

2 address pins allow 16 devices on the same bus

10-lead MSOP

APPLICATIONS

Power monitoring/power budgeting

Central office equipment

Telecommunications and data communications 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

through an I

C® interface.

An internal current sense amplifier measures 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.

An industry-standard I

C interface allows a controller to read

current and voltage data from the ADC. Measurements can be

initiated by an I

C command or via the convert (CONV) pin.

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

whenever it is required. Up to 16 unique I

C addresses can be

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 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. When this event occurs, the ALERTB output asserts.

FUNCTIONAL BLOCK DIAGRAM

ADM1191

SENSE

SETV

VCC

CONV

MUX

ALERT

GND

COMPARATOR

CURRENT

SENSE

AMPLIFIER

SDA

SCL

ALERTB

05804-001

12-BIT

ADC

Figure 1.

SENSE

P = VI

CONTROLLER

ADM1191

SENSEVCC

SDA

SCL

SDA

SCL

GND

ALERTB

CONV

3.15V TO 26V

SETV

INTERRUPT

05804-002

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.

Summary of content (16 pages)

PAGE 1
FEATURES APPLICATIONS Power monitoring/power budgeting Central office equipment Telecommunications and data communications 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 through an I2C® interface. An internal current sense amplifier measures voltage across the sense resistor in the power path via the VCC pin and the SENSE pin.
PAGE 2
ADM1191 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Identifying the ADM1191 on the I2C Bus..................................9 Applications ....................................................................................... 1 General I2C Timing .......................................................................9 General Description .........................................................................
PAGE 3
Data Sheet ADM1191 SPECIFICATIONS VCC = 3.15 V to 26 V, TA = −40°C to +85°C, typical values at TA = 25°C, unless otherwise noted. Table 1. Parameter VCC PIN Operating Voltage Range, VCC Supply Current, ICC Undervoltage Lockout, VUVLO Undervoltage Lockout Hysteresis, VUVLOHYST CONV PIN Input Current, ICONV Logic Low Threshold, VCONVL Logic High Threshold, VCONVH MONITORING ACCURACY 1 Current Sense Absolute Accuracy 0°C to +70°C 0°C to +85°C −40°C to +85°C Min Typ 3.15 1.7 2.
PAGE 4
ADM1191 Data Sheet Parameter A0 PIN, A1 PIN Set Address to 00, VADRLOWV Set Address to 01, RADRLOWZ Min Typ Max Unit Conditions 0 80 120 0.8 160 V kΩ Set Address to 10, IADRHIGHZ −0.3 +0.3 µA Set Address to 11, VADRHIGHV Input Current for 00 Decode, IADRLOW 2 −40 5.5 V µA Low state Resistor to ground state, load pin with specified resistance for 01 decode Open state, maximum load allowed on the A0 pin or A1 pin for 10 decode High state VADR = 0 V to 0.8 V 6 µA VADR = 2.0 V to 5.
PAGE 5
Data Sheet ADM1191 ABSOLUTE MAXIMUM RATINGS THERMAL CHARACTERISTICS Table 2. Parameter VCC Pin SENSE Pin CONV Pin SETV Pin ALERTB Pin SDA Pin, SCL Pin A0 Pin, A1 Pin Storage Temperature Range Operating Temperature Range Lead Temperature (Soldering, 10 sec) Junction Temperature θJA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. Rating 30 V 30 V −0.3 V to +6 V 6V 30 V −0.3 V to +6 V −0.
PAGE 6
ADM1191 Data Sheet PIN CONFIGURATION AND FUNCTION DESCRIPTIONS VCC 1 10 ALERTB SENSE 2 ADM1191 9 CONV 3 TOP VIEW (Not to Scale) 8 A0 7 SDA 6 SCL SETV 5 05804-003 GND 4 A1 Figure 3. Pin Configuration Table 4. Pin Function Descriptions Pin No. 1 Mnemonic VCC 2 SENSE 3 CONV 4 5 GND SETV 6 7 8 SCL SDA A0 9 A1 10 ALERTB Description Positive Supply Input Pin. The operating supply voltage range is from 3.15 V to 26 V.
PAGE 7
Data Sheet ADM1191 TYPICAL PERFORMANCE CHARACTERISTICS 1000 2.0 900 HITS PER CODE (1000 READS) 1.8 1.6 ICC (mA) 1.4 1.2 1.0 0.8 0.6 800 700 600 500 400 300 200 0.4 100 0 0 4 8 12 16 20 24 28 VCC (V) 2046 05804-021 0 Figure 4. Supply Current vs. Supply Voltage 2047 2048 2049 2050 CODE 05804-060 0.2 Figure 7. ADC Noise with Current Channel, Midcode Input, and 1000 Reads 1000 2.0 900 HITS PER CODE (1000 READS) 1.8 1.6 ICC (mA) 1.4 1.2 1.0 0.8 0.
PAGE 8
ADM1191 Data Sheet 0.60 4 0.55 3 ALERTB OUTPUT LOW (V) 0.50 2 INL (LSB) 1 0 –1 –2 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 –3 500 1000 1500 2000 2500 3000 3500 4000 CODE 0 –40 05804-023 0 –20 0 20 40 60 05804-047 0.05 –4 80 TEMPERATURE (°C) Figure 10. INL for ADC Figure 13. ALERTB Output Low Voltage vs. Temperature @ 1 mA 1.0 4 3 ALERTB OUTPUT LOW (V) 0.8 DNL (LSB) 2 1 0 –1 –2 0.6 0.4 0.
PAGE 9
Data Sheet ADM1191 VOLTAGE AND CURRENT READBACK The peripheral whose address corresponds to the transmitted address responds by pulling the data line low during the low period before the ninth clock pulse, known as the acknowledge bit, and holding it low during the high period of this clock pulse. All other devices on the bus remain idle while the selected device waits for data to be read from it or written to it. If the R/W bit is 0, the master writes to the slave device.
PAGE 10
ADM1191 Base Address A1 Pin State Floating Floating High High High High A0 Pin State Floating High Ground Resistor to ground Floating High A1 Pin Logic State 10 10 11 11 11 11 A0 Pin Logic State 10 11 00 01 10 11 Address in Binary1 0111010X 0111011X 0111100X 0111101X 0111110X 0111111X Address in Hex 0x74 0x76 0x78 0x7A 0x7C 0x7E X = don’t care.
PAGE 11
Data Sheet ADM1191 WRITE AND READ OPERATIONS Table 6. I2C Abbreviations Abbreviation S P R W A N WRITE COMMAND BYTE In the write command byte operation, the master device sends a command byte to the slave device, as follows: 1. 2. 3. 4. Condition Start Stop Read Write Acknowledge No acknowledge 5. 6. QUICK COMMAND 1 The quick command operation allows the master to check if the slave is present on the bus, as follows: 3. 4. The master device asserts a start condition on SDA.
PAGE 12
ADM1191 Data Sheet WRITE EXTENDED COMMAND BYTE 1. 2. 3. 4. 5. 6. The master device asserts a start condition on SDA. The master sends the 7-bit slave address, followed by the write bit (low). The addressed slave device asserts an acknowledge on SDA. The master sends the register address byte. The MSB of this byte is set to 1 to indicate an extended register write. The two LSBs indicate which of the three extended registers is to be written to (see Table 8). All other bits should be set to 0.
PAGE 13
Data Sheet ADM1191 READ VOLTAGE AND/OR CURRENT DATA BYTES Voltage and Current Readback 9. The master asserts a no acknowledge on SDA. 10. The master asserts a stop condition on SDA, and the transaction ends. For cases where the master is reading voltage only or current only, two data bytes are read and Step 7 and Step 8 are not required. 1 The ADM1191 digitizes both voltage and current. Three bytes are read back in the format shown in Table 12.
PAGE 14
ADM1191 Data Sheet Table 15. Status Byte Operations Bit 0 1 2 Name ADC_OC ADC_ALERT OC 3 OC_ALERT 4 5 OFF_STATUS OFF_ALERT Function An ADC-based overcurrent comparison is detected on the last three conversions. An ADC-based overcurrent trip has occurred, causing the alert. Cleared by writing to Bit 4 of the ALERT_EN register. An overcurrent condition is present (that is, the output of the current sense amplifier is greater than the voltage on the SETV input).
PAGE 15
Data Sheet ADM1191 APPLICATIONS INFORMATION The ALERTB output is an open-drain pin with 30 V tolerance. This output can be used as an overcurrent flag by connecting it to the general-purpose logic input of a controller. During normal operation, this output is pulled high (an external pull-up resistor should be used because this is an open-drain pin). When an overcurrent condition occurs, the ADM1191 pulls this output low. The ALERTB pin is disabled by default on power up.
PAGE 16
ADM1191 Data Sheet OUTLINE DIMENSIONS 3.10 3.00 2.90 10 3.10 3.00 2.90 5.15 4.90 4.65 6 1 5 PIN 1 IDENTIFIER 0.50 BSC 0.95 0.85 0.75 15° MAX 1.10 MAX 0.30 0.15 6° 0° 0.70 0.55 0.40 0.23 0.13 COMPLIANT TO JEDEC STANDARDS MO-187-BA 091709-A 0.15 0.05 COPLANARITY 0.10 Figure 27.