ABSTRACT
Function circuits are finding application in signal processing, data acquisition, communications, controls, instrumentation, and analog computations. Numerous useful applications of function circuits include performing as automatic gain control, voltage-controlled waveform generator, voltage-controlled quadrature oscillator, voltage-controlled exponentiator, and mass gas flow measurement. This chapter discusses a systematic method for approximating a given function and then modeling it with analog function circuits. The amplitude stability of the output signal depends on the stability of the DC reference voltage and the integrator gain. The numerator of the divider accepts bipolar voltages, and the denominator accepts only negative voltages. The rate at which the loop can realize after sudden changes in input level depends on the cut-off frequency of the lowpass filter and the integrator time constant.
