Pulse Height Analyzer

2022

Pulse height analysers are conceptually simple devices — they report the peak voltage of an analog pulse, and they are useful for radiation spectroscopy. An oscilloscope set to trigger normally and measure pulse height accomplishes this task, but most oscilloscopes are not equipted to automatically record the pulse height of every pulse detected for future analysis. A microcontroller could do the job if its ADC sample rate is fast enough (often pulses from radiation detectors are less than a microsecond in duration), but I wanted to build something that could interface with an arbitrarially low speed ADC. Or volt meter!

Pulse Height Analyzer Circuit

Effectively, what I have built is an infinite hold time peak detector. It has two stages: an analog peak detector followed by a digital sample and hold circuit. The 'analyzer' aspect is seperate from this, but any ADC with a sample rate greater than some multiple fo the expected event rate and some means of recordign measurements is all that is needed to complete the system.