SPICE simulation of a linear delta modulator. The delta modulation is performed by comparing the input signal with an approximation of this signal in a 741 operational amplifier used as a comparator. The corresponding error signal is sampled and quantized to a positive or negative signal. This signal generates an approximate signal using a decoder and is transmitted to a remote decoder.After each sample, the approximate signal increments or decrements by the step size. The comparator output is a delta-modulated carrier signal connected to a Schmitt trigger, and the flip-flop output is integrated and is one of the inputs to the comparator.