A voltage detecting device and an analog-to-digital converter (ADC) using
the same are provided. The voltage detecting device determines whether
input voltage is higher than threshold voltage based on contact of a
strip and a membrane. Therefore, high resolution and high speed operation
is possible, but with consuming lower power, and an element capable of
performing the function of resistor and comparator is provided.
Furthermore, a more effective ADC may be provided using the above.