The ADM1025/ADM1025A1 is a complete system hardware monitor for microprocessor-based systems, providing measurement and limit comparison of various system parameters. Five voltage measurement inputs are provided for monitoring 2.5 V, 3.3 V, 5 V, and 12 V power supplies and the processor core voltage. The ADM1025/ADM1025A can monitor a sixth power supply voltage by measuring its own VCC. One input (two pins) is dedicated to a remote temperature-sensing diode, and an onchip temperature sensor allows ambient temperature to be monitored. The ADM1025A has open-drain VID inputs while the ADM1025 has on-chip 100 k pull-ups on the VID inputs. Measured values and in/out of limit status can be read out via an I2C compatible serial System Management Bus. The device can be controlled and configured over the same serial bus. The device also has a programmable INT output to indicate undervoltage, overvoltage, and overtemperature conditions.