摘要 |
A method and apparatus for controlling the time constant of an integrator linearly as a function of a control voltage. A ramp signal having a negative slope proportional to the magnitude of the applied signal generates a pulse each time it decays to a predetermined level. An accumulated count of the pulses is transformed into an analog output signal by a digital-to-analog converter. Each time a pulse is generated the ramp signal is reset to a level determined by the control voltage, hence, the time constant of the integrator is a linear function of the magnitude of the control voltage. |