Digital pulse-width modulated system for providing current to a load

A method of producing a pulse-width modulated signal for providing current through a load according to an input signal, the method comprising the steps of:

• a) providing a reference square wave, the square wave having a plurality of pulses of equal width, each pulse having a leading edge and a trailing edge, wherein the pulses are spaced apart by a time interval equal to the width of the pulses, the width of the pulses being called P,
• b) repeatedly sampling the input signal at times corresponding to edges of the pulses of the reference square wave, to produce a series of values, the values being called E.sub.0, E.sub.1, E.sub.2, . . . E.sub.n, where n is a positive integer, and generating a series of intermediate pulses, each intermediate pulse having a width, wherein the width of every other intermediate pulse corresponds to E.sub.0, E.sub.2, E.sub.4 . . . , and wherein the widths of the remaining intermediate pulses correspond to P-E.sub.1, P-E.sub.3, P-E.sub.5, . . . , each of the intermediate pulses having a leading edge corresponding to successive edges of the reference square wave,
• c) generating a series of output pulses, the output pulses having widths, wherein the widths of the output pulses correspond to 2P-(E.sub.0 +E.sub.1), 2P-(E.sub.2 +E.sub.3), 2P-(E.sub.4 +E.sub.5), . . . , and wherein there are intervals between the output pulses, the intervals having widths corresponding to E.sub.1 +E.sub.2, E.sub.3 +E.sub.4, E.sub.5 +E.sub.6, . . . , and
• d) using the output pulses to provide current through the load.