Patent ID: 7719377

Claim:
A pulse step modulator comprising a plurality of series connected unit step power amplifier modules with each said module being turned on by a turn-on signal to provide a unit step voltage of a given value; an output circuit connected to the modules for providing an output voltage to a load and wherein said output voltage is a multiple of said unit step voltages in dependence upon the number of modules that are turned on; said modules being sequentially turned on in a given order and are turned off in a reverse order as a time varying input signal increases and decreases in value; an encoder that provides turn-on signals with each turn-on signal being applied to a selected one of the modules with the number of turn-on signals provided varying as a function of the magnitude of the input signal; and a controller that alternately enables and disables (in a swapping manner) one of a pair of associated modules as the magnitude of the input signal increases and decreases.