A driving circuit for generating a required firing current for a safety device comprising an arrangement of a first transistor (M2) connected in series with a second transistor (M3); and a power control transistor (M1) connected in series with the first transistor; characterised in that the first and second transistors operate in fully switched on mode (Rds(on)) and the required firing current (I(squib)) is generated by means of varying the voltage (Vc) across the gate source of power control transistor and the first and second transistors in a predetermined manner.