1. A method comprising: receiving an analog signal comprising a pulse; directing a first portion of the analog signal to a differentiator and a second portion of the analog signal to a signal buffer; differentiating the first portion of the analog signal, using the differentiator, to provide a differentiated signal; detecting, using a comparator, a zero-crossing in the differentiated signal; delaying the second portion of the analog signal by a delay amount, using the signal buffer, to provide a time-delayed analog signal; in response to detecting the zero-crossing, causing a measurement of the time-delayed analog signal to be obtained; determining a measurement time associated with the measurement; and outputting the measurement and the measurement time.