Analog-to-Digital Conversion Based on a Voltage-to-Frequency Converter

In this paper we discuss a method of analog-to-digital conversion based on a voltage-to-frequency converter (VFC). The basic principle of a VFC circuit is given in order to derive the exact relationship between the characteristics of the output pulse train and the input voltage. We illustrate this theoretical analysis with an example of a simple VFC circuit. The VFC output signal has to be transformed in a binary number proportional to the VFC input voltage. This is done by a digital circuit interfacing the VFC and the computer and a simple calculation in the computer. Finally, we discuss some elements influencing the quantization error of the conversion.