The ADM1025/ADM1025A 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 on-chip 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 over-temperature conditions. The ADM1025/ADM1025A's 3.0 V to 5.5 V supply voltage range, low supply current, and I2C-compatible interface make it ideal for a wide range of applications. These include hardware monitoring and protection applications in personal computers, electronic test equipment, and office electronics.