The MLX90804 is a power control IC for controlling the speed of AC motors by m eans of a triac. The speed setting is done by applying a ratiometric voltage at pin SET (usually by m eans of a potentiometer). This speed setting is compared with the pulse rate at the SPD input. The input is compatible with inductive and magnetic detectors. The calculation of the required phase angle is done with a PI regulator, which is fully digital. A soft start function is implemented to eliminate high current peaks at startup. Also available are an overload and overspeed protection. The build in Frequency Locked Loop compensates for variations in the mains frequency giving a stable frequency independent trigger control. Several parameters can be adjusted by mask programming: minimum and maximum speed, soft start delay, gain settings of the PI regulator, ...