High speed peak detector for glitch-catching used in digital storage scopes

A double peak-detection circuit, monitoring maximum and minimum values of the analog input to the ADC between successive sampling points does much to improve the performance of a digital storage scope, especially as regards glitch-catching, The basic circuit, the peak detector, which is presented in this paper, tracks an analog input signal until a maximum amplitude is reached. The maximum value is retained as a peak voltage on a hold capacitor. To provide maximum and minimum peak detection, two such circuits are used, both being supplied from the analog input, one directly and the other inverted. The outputs are sampled alternately, before being fed to the ADC.