Digital samples corresponding to a pulsed input signal are provided from an ADC to a memory for storage and to a pulse extraction circuit. The pulse extraction circuit detects the leading and trailing edges of pulses in the input signal. The digital samples are stored in both a Current memory buffer and a Next memory buffer. When a pulse trailing edge is detected, the Current buffer is stopped from storing further samples, the Next buffer becomes the Current buffer and a new buffer becomes the Next buffer. Digital data samples are then provided from the (previous) Current buffer after it has stopped storing samples.