DESIGN OF FAST FREQUENCY-TO-VOLTAGE CONVERTER USING SUCCESSIVE-APPROXIMATION TECHNIQUE

摘要

In this paper, current conveyors, an up-down counter, and a high-speed digital-to-analog (D/A) converter are employed to implement a frequency-to-voltage converter (FVC). Based on the characteristics of the successive-approximation technique, a conversion time less than one cycle of input signal can be achieved. Thus, the transient variation on input signal frequency can be detected rapidly. Input signal frequencies ranging from 55 Hz to 2 MHz are tested with different choices of RC components and update clock rates. The output ripple voltage is verified so little that no lowpass filter is needed. The experimental and simulation results demonstrate the static characteristics and dynamic responses of the proposed FVC.