The LM85, hardware monitor, has a two wire digital interface compatible with SMBus 2.0. Using an 8-bit Delta-Sigma ADC, the LM85 measures: the temperature of two remote diode connected transistors as well as its own die and the VCCP, 2.5V, 3.3VSBY, 5.0V, and 12V supplies (internal scaling resistors). To set fan speed, the LM85 has three PWM outputs that are each controlled by one of three temperature zones. The LM85 includes a digital filter that can be invoked to smooth temperature readings for better control of fan speed. The LM85 has four tachometer inputs to measure fan speed. Limit and status registers for all measured values are included.