Patent ID: 8207788
Filing Date: 2012-06-26
Classification: H03F

Abstract:
1. A Class D amplifier, comprising: an H-Bridge amplifier, the H-Bridge amplifier having a first output terminal and a second output terminal; and an adjustable differential negative feedback network coupled to receive output signals of the H-Bridge amplifier, the adjustable differential negative feedback network having at least a left feedback path and a right feedback path; wherein the adjustable differential negative feedback network is operable to modify the net gain of at least one of the left feedback path and the right feedback path; wherein the adjustable differential feedback network comprises a left feedback path and a right feedback path: wherein the left feedback path comprises a first voltage divider, the first voltage divider having a first circuit element coupled between the first output terminal of the H-Bridge amplifier and a first intermediate node, a second circuit element coupled between the first intermediate node and a ground node, a third circuit element coupled between the first intermediate node and an output terminal of the left feedback path, and a fourth circuit element coupled between the first intermediate node and a common-mode bias control terminal of a first stage of a loop filter; and wherein the right feedback path comprises a second voltage divider, the second voltage divider having a fifth circuit element coupled between the second output terminal of the H-Bridge amplifier and a second intermediate node, a sixth circuit element coupled between the second intermediate node and the ground node, a seventh circuit element coupled between the second intermediate node and an output terminal of the right feedback path, and an eighth circuit element coupled between the second intermediate node and the common-mode bias control terminal of the first stage of the loop filter.