A device that converts an analog information signal to a pulse format. A pulse modulator encodes the amplitude information at a particular time by a set of short- or long-duration pulses using such methods as pulse-amplitude, pulse-width, pulse-position, pulse-density, or pulse-code modulation. A pulse modulator, therefore, accepts a continuous analog input signal and provides a pulse output that conveys the amplitude of the continuous analog signal as seen at an observation, or sampling, time t_s, often optimistically described as a sampling instant.