Very Low-Drift Complimentary Semiconductor Network dc Amplifiers

This paper describes a new approach to the fabrication of a variety of monolithic direct coupled amplifiers with typical equivalent differential input drifts of 0.1 to 0.2 /spl mu/v//spl deg/C. These amplifiers exhibit a significant improvement in temperature stability over current state-of-the-art IC amplifiers, and complete with chopper stabilized units in many respects. In these amplifiers, a monolithic silicon wafer is maintained at a near constant temperature by means of an electrically separate temperature-control circuit diffused within the same substrate. A thermal-electrical analogy is used to predict temperature gradients on the surface of the silicon bar. Performance of several amplfier circuit configurations is discussed.