An analog-to-digital converter (ADC) generates a digital word proportional
to the amplitude of an input pulse. In nuclear applications, ADCs are used to digitize the output signals from spectroscopy amplifiers. Since these amplifiers generate output pulses whose amplitudes are directly proportional to the energies of the incident radiation, the ADC can be used with an amplifier and a multichannel analyzer (MCA) to generate energy distributions (spectra) of radioactive
samples.