The protection circuit has a semiconductor structure incorporating a number of pnp regions (I,II,...), with one of their p regions (13) coupled together and connected to one of the voltage supply terminals (1) for the IC. Similarly the other p regions (14) are coupled together and connected to the opposite voltage supply terminal for the IC. Pref. the pnp regions are formed as lateral pnp bipolar transistors within a semiconductor body having a p-- substrate (10) and an overlying n- layer (12), incorporating both the p-regions.
