Asymmetrically-switched modulation scheme

摘要

An asymmetric modulation scheme may be used to drive two output nodes coupled to a load. The asymmetric modulation scheme may be one-sided such that the switching rate of a first output node is lower than the switching rate of a second output node. The first output node may be switched only to change a direction of current between the first output node and the second output node, while the second output node is switched to convey the information of an input signal. The asymmetric modulation scheme may be used to drive a speaker to reduce noise at the first output node to improve accuracy of current monitoring through the speaker by a current monitor coupled at the first output node.

主权项

1. An apparatus, comprising:
a processor comprising a first input node, a first output node, and a second output node, in which the processor is configured to: receive at least one analog signal at the first input node; modulate the first output node at a first constant potential when the received analog signal is larger than a first threshold value and at a second constant potential when the received analog signal is smaller than a second threshold value, wherein the first constant potential is different from the second constant potential; and modulate the second output node by switching the second output node between the first constant potential and the second constant potential corresponding to the received analog signal, wherein the second output node is switched between the first constant potential and the second constant potential while the first output node is held at either the first constant potential or the second constant potential.