This document describes the features and characteristics of the ADM1293/ADM1294 digital power monitor with PMBus interface. The product offers high accuracy current monitoring, low sense voltage, dual voltage monitoring, power accumulation, and other functions.
The ADM1293 and ADM1294 are high accuracy integrated digital power monitors that offer digital current, voltage, and power monitoring using an on-chip, 12-bit analog-to-digital converter (ADC), communicated through a PMBus compliant I2C interface. These devices acquire the current by measuring the voltage difference across the external sense resistor. This voltage is amplified and digitized by an internal 12-bit ADC. The same ADC can also sample the primary input voltage and an auxiliary input voltage. The internal digital block can perform multiplication of the current and primary input voltage for power calculation. The ADM1293 /ADM1294 also feature a power accumulator for energy metering. An industry-standard PMBus interface allows a master controller to read back these data from the device. The master controller can then combine this information with a known sense resistor value to calculate the current, voltage, power, and energy consumption over time on the monitored rail. In conditions such as overcurrent, overvoltage, undervoltage, and overpower, the ADM1293 /ADM1294 devices can generate an interrupt signal to the microprocessor through the GPOx/ ALERTx outputs. The threshold for these conditions is digitally programmed via PMBus. The ADM1293 is designed for high-side supply monitoring with a voltage monitoring range from 0 V to 20 V. The ADM1294 is designed for low-side supply monitoring. Its integrated shunt regulator allows it to be powered and to monitor supply in wide voltage ranges. The ADM1293 /ADM1294 are available in 4 mm × 4 mm 16-lead LFCSP and 14-lead TSSOP packages with a specified operating ambient temperature range from −40°C to +105°C for the ADM1293 and an operating junction temperature range from −40°C to +105°C for the ADM1294.
| Operating Voltage Range (ADM1293) | 2.95 V to 20 V |
|---|---|
| Operating Junction Temperature (ADM1294) | -40°C to +105°C |
| Quiescent Current (ADM1293) | 3.3 mA |
| Quiescent Current (ADM1294) | 3.6 mA |
| Current Sense Absolute Error (128 sample averaging) | 0.33% at ±20 mV sense voltage |
| Voltage Monitoring Range (ADM1293) | 0 V to 20 V |
| Voltage Monitoring Range (ADM1294) | Low-side supply monitoring |
| Package Options | 4 mm × 4 mm 16-lead LFCSP and 14-lead TSSOP |
The ADM1293 has an operating ambient temperature range from −40°C to +105°C.
The devices communicate through a PMBus compliant I2C interface.
Applications include power monitoring/power budgeting, central office equipment, telecommunications and data communications equipment, and PCs/servers.