An analog-to-digital conversion device is provided that uses pulse delay
circuits to convert an input voltage into numerical data and offers a high
resolution in analog-to-digital conversion or a high analog-to-digital
conversion rate. The analog-to-digital conversion device includes an
analog-to-digital conversion unit having a pulse delay circuit composed of
a plurality of delay units. The delay units are driven with a voltage
produced by amplifying or shifting an input voltage. The number of delay
units through which a pulse signal has passed during a predetermined
sampling cycle is adopted as a digitized value of the input voltage.
Herein, delay units constituting another pulse delay circuit are driven
with a voltage produced by inversely amplifying or shifting the input
voltage. Every time the number of delay units through which a pulse signal
has passed within the pulse delay circuit reaches a predetermined value
determined with a set value, a sampling signal is transferred to the
analog-to-digital conversion unit.
