for use with an inverter including cmos transistors , a device for compensating inherent variations in electrical properties among mos integrated circuits , the device including a generator of a reference signal representing conduction of a reference transistor ; two threshold amplifiers ; two switches ; and two compensating transistors . if , for example , a first transistor is weak , switches are employed to selectively activate one or more supplementary transistors to add a compensating current to a current furnished by the first transistor so as to provide a reliably uniform output current as compared with a plurality of other mos integrated circuits .