Charge injection reduction technique in single and multi-reference switching amplifiers

Abstract

A method of adding a minimum pulse width to the switching devices of both outputs of a switching differential pair enhances the performance of a switching amplifier. When used with similar switching devices at similar temperatures, this results in injecting a similar error term into both sides of a differential output, thus presenting it as a null common-mode output. That is, by correlating the output to differences between the differential pairs, accurate representations by the switching device outputs are achieved. Although the invention is described in conjunction with two switching devices per side of the differential output pair, operation with three or more switching devices per side, as seen in multi-reference amplifiers, may be accommodated by the invention.