The ADM1026 is a complete system hardware monitor for microprocessor-based systems, providing measurement and limit comparison of various system parameters. The ADM1026 has up to 19 analog measurement channels. Fifteen analog voltage inputs are provided, five of which are dedicated to monitoring +3.3 V, +5.0 V, and 12 V power supplies, and the processor core voltage. The ADM1026 can monitor two other power supply voltages by measuring its own VCC and the main system supply. One input (two pins) is dedicated to a remote temperature-sensing diode. Two additional pins can be configured as general-purpose analog inputs to measure 0 V to 2.5 V, or as a second temperature sensing input. The eight remaining inputs are general-purpose analog inputs with a range of 0 V to 2.5 V or 0 V to 3.0 V. The ADM1026 also has an on-chip temperature sensor. The ADM1026 has eight pins that can be configured for fan speed measurement or as general-purpose logic I/O pins. Another eight pins are dedicated to general-purpose logic I/O. An additional pin can be configured as a general-purpose I/O or as the bidirectional THERM pin. Measured values can be read out via a 2-wire serial system management bus, and values for limit comparisons can be programmed over the same serial bus. The high speed, successive approximation ADC allows frequent sampling of all analog channels to ensure a fast interrupt response to any out-of-limit measurement.