Digital Power Monitor with PMBus Interface Data Sheet ADM1293/ADM1294 FEATURES FUNCTIONAL BLOCK DIAGRAMS SENSEP SENSEN Monitor current and two voltages High accuracy current monitoring at low sense voltage ADM1293 0.33% accurate at 20 mV sense voltage over temperature VCC Common-mode sense voltage from 0 V to 20 V (ADM1293) INTERNAL LDO VCAP SUPPLY Support high-side and low-side current sensing Integrated shunt regulator for wide supply input (ADM1294) RANGE MUX VIN ADC SELECT Reports current, voltage, and power EN VAUX Power accumulation for energy metering GPO1/ALERT1/CONV Bidirectional current sensing ADDRESS PMBUS AND LOGIC DECODER GPO2/ALERT2 Digitally programmable overcurrent alert Multifunctional pins with user configurable functions ADR1 ADR2 GND SCL SDAI SDAO ADC conversion enable input Figure 1. ADM1293 Functional Block Diagram Multisource alert output User-controllable GPO VSHUNT Peak detect registers for current, voltage, and power ADM1294 PMBus fast mode compliant interface VCAP LDO ADR1 ADDRESS VEE Separate SDA I/O for easy isolated communication DECODER ADR2 IC POWER SUPPLY Two address pins for 16 unique IC addresses GPO1/ALERT1/CONV RANGE Available in 4 mm 4 mm, 16-lead LFCSP and 14-lead TSSOP VIN GPO2/ALERT2 SELECT PMBUS ADC Operation temperature range MUX AND SDAI VAUX LOGIC EN ADM1293 T = 40C to +105C SDAO A SCL ADM1294 T = 40C to +105C J VEE APPLICATIONS SENSEN SENSEP Power monitoring/power budgeting Central office equipment Figure 2. ADM1294 Functional Block Diagram Telecommunications and data communications equipment PCs/servers GENERAL DESCRIPTION The ADM1293 and ADM1294 are high accuracy integrated digital In conditions such as overcurrent, overvoltage, undervoltage, power monitors that offer digital current, voltage, and power and overpower, the ADM1293/ADM1294 devices can generate an interrupt signal to the microprocessor through the monitoring using an on-chip, 12-bit analog-to-digital converter 2 (ADC), communicated through a PMBus compliant I C interface. GPOx/ALERTx outputs. The threshold for these conditions is digitally programmed via PMBus. These devices acquire the current by measuring the voltage differ- ence across the external sense resistor. This voltage is amplified The ADM1293 is designed for high-side supply monitoring and digitized by an internal 12-bit ADC. The same ADC can also with a voltage monitoring range from 0 V to 20 V. The sample the primary input voltage and an auxiliary input voltage. ADM1294 is designed for low-side supply monitoring. Its The internal digital block can perform multiplication of the integrated shunt regulator allows it to be powered and to current and primary input voltage for power calculation. The monitor supply in wide voltage ranges. ADM1293/ADM1294 also feature a power accumulator for The ADM1293/ADM1294 are available in 4 mm 4 mm 16-lead energy metering. An industry-standard PMBus interface allows a LFCSP and 14-lead TSSOP packages with a specified operating master controller to read back these data from the device. The ambient temperature range from 40C to +105C for the master controller can then combine this information with a known ADM1293 and an operating junction temperature range from sense resistor value to calculate the current, voltage, power, and 40C to +105C for the ADM1294. energy consumption over time on the monitored rail. Rev. B Document Feedback 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20142015 Analog Devices, Inc. All rights reserved. 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. Technical Support www.analog.com 11891-001 11891-002ADM1293/ADM1294 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Digital Comparator Mode ......................................................... 29 Applications ....................................................................................... 1 Application Diagrams .................................................................... 30 Functional Block Diagrams ............................................................. 1 PMBus Command Reference........................................................ 32 General Description ......................................................................... 1 PMBus Command Descriptions .................................................. 33 Revision History ............................................................................... 3 Clear Faults Register .................................................................. 33 Specifications ..................................................................................... 4 PMBus Capability Register ....................................................... 33 Electrical Characteristics ............................................................. 4 IOUT OC Warning Limit Register .......................................... 33 Serial Bus Timing Characteristics .............................................. 7 VIN OV Warning Limit Register ............................................. 33 Absolute Maximum Ratings ............................................................ 8 VIN UV Warning Limit Register ............................................. 34 Thermal Characteristics .............................................................. 8 PIN OP Warning Limit Register .............................................. 34 ESD Caution .................................................................................. 8 Status Byte Register .................................................................... 34 Pin Configurations and Function Descriptions ........................... 9 Status Word Register .................................................................. 34 Typical Performance Characteristics ........................................... 11 IOUT Status Register ................................................................. 35 Theory of Operation ...................................................................... 14 Input Status Register .................................................................. 35 Powering the ADM1293 ............................................................ 14 Manufacturer Specific Status Register ..................................... 36 Powering the ADM1294 ............................................................ 14 Read EIN Register ...................................................................... 36 Optional Power Monitor Inputs Filtering ............................... 16 Read EOUT Register .................................................................. 37 Power Monitor ............................................................................ 16 Read VIN Register...................................................................... 37 PMBus Interface ............................................................................. 18 Read IOUT Register ................................................................... 37 Device Addressing ...................................................................... 18 Read PIN Register ...................................................................... 37 SMBus Protocol Usage ............................................................... 19 PMBus Revision Register .......................................................... 38 Packet Error Checking ............................................................... 19 Manufacturer ID Register ......................................................... 38 2 Partial Transactions on I C Bus ................................................ 19 Manufacturer Model Register ................................................... 38 SMBus Message Formats ........................................................... 19 Manufacturer Revision Register ............................................... 38 Group Commands ...................................................................... 21 Maximum IOUT Register ......................................................... 38 Information Commands ............................................................ 21 Peak VIN Register ...................................................................... 39 Status Commands ....................................................................... 21 Peak VAUX Register .................................................................. 39 ALERTx Power Monitor Control Register .............................................. 39 GPOx and Pin Setup Commands ............................ 22 Power Monitor Configuration Register................................... 40 Power Monitor Commands ...................................................... 22 Alert 1 Configuration Register ................................................. 41 Warning Limit Setup Commands ............................................ 24 Alert 2 Configuration Register ................................................. 41 PMBus Direct Format Conversion .......................................... 24 Device Configuration Register ................................................. 42 Energy Meter Value Conversion .............................................. 26 Maximum PIN Register............................................................. 42 Energy Meter Value to PMBus Standard Data Conversion .. 27 Read PIN (Extended) Register ................................................. 43 Voltage and Current Conversion Using LSB Values .............. 27 Read EIN (Extended) Register ................................................. 43 ALERTx Pin Behavior .................................................................... 28 Read VAUX Register .................................................................. 43 Warnings ...................................................................................... 28 VAUX OV Warning Limit Register ......................................... 43 Generating an Alert .................................................................... 28 VAUX UV Warning Limit Register ......................................... 44 Handling/Clearing an Alert ...................................................... 28 Minimum IOUT Register.......................................................... 44 SMBus Alert Response Address (ARA) .................................. 28 Minimum PIN Register ............................................................. 44 Example Use of SMBus ARA .................................................... 29 Rev. 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