The FX364B is an instrumentation Analog Front End (AFE) integrated circuit for time-domain reflectometry step stimulus and sampling of single-ended transmission sub-systems. It integrates two high-speed functional blocks: i) a controlled-amplitude single-ended voltage step generator – a Time Domain Reflectometer (TDR) step-stimulus, and; ii) a differential, dual-rank, sample-and-hold – to digitize the reflected voltage waveform that indicates an impedance discontinuity. With the step-generator disabled, the sample and hold amplifier (S&HA) acts as a single Ended Digital Sampling Oscilloscope (DSO) AFE, facilitating sampling of 28G NRZ or PAM4 sample-rate eyes.