The HEF4752V is a circuit for a.c. motor speed control utilizing LOCMOS technology. The circuit synthesizes three 120° out of phase signals, of which the average voltage varies sinusoidally with time in the frequency range 0 to 200 Hz. The method employed is based upon the pulse width modulation principle, in order to achieve a sufficient accuracy of the output voltages over the whole frequency range. A pure digital waveform generation is used. All outputs are of the push-pull type. Inputs and outputs are protected against electrostatic effects in a wide variety of device-handling situations. However, to be totally safe, it is desirable to take handling precautions into account.