Design of Fast Frequency-to-Voltage Converter Using Successive-Approximation Technique

Abstract

In this paper, current conveyors, an up-down counter, and a high-speed digitalto-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.

A MEMS Interface IC With Low-Power and Wide-Range Frequency-to-Voltage Converter for Biomedical Applications

“…This block can be employed in instrumentation and measurement systems involving frequency conversion [39], [40], phase-locked loops (PLLs), frequency-locked loops (FLLs) [39], [41]- [44], clock buffers [45], and ring oscillators [34], [36], [46]. For the implementation of an FVC block, there are mainly two approaches, including counter-based circuits [34], [40] and integrator-based circuits [41], [42], [47]. The counter-based circuits, including successive-approximation technique [40] use counters and digital-to-analog converters (DAC) that requires a very high reference clock frequency compared to the measured signals for high accuracy.…”

“…For the implementation of an FVC block, there are mainly two approaches, including counter-based circuits [34], [40] and integrator-based circuits [41], [42], [47]. The counter-based circuits, including successive-approximation technique [40] use counters and digital-to-analog converters (DAC) that requires a very high reference clock frequency compared to the measured signals for high accuracy. The need for a high frequency clock limits the usage for high frequency measuring signals [41].…”