Measurement circuit components are included in an integrated circuit fabricated on a semiconductor substrate. A method is provided for controlling the speed of a cooling fan provided to cool an integrated circuit in which includes the steps of receiving a voltage from a thermal diode, addressing a table of digital temperatures by incrementing the address of the table entries every clock cycle of a circuit clock, converting the addressed data to a second voltage representing temperature, comparing the first voltage to the second voltage, providing a resulting temperature when both the first and second voltages are equal, and adjusting the fan speed accordingly.