US 11,837,999 B2
Audio amplifier having idle mode
Rajdeep Mukhopadhyay, Edinburgh (GB); Euan Murphy, West Lothian (GB); Matt Felder, Austin, TX (US); and Simon Quinn, Edinburgh (GB)
Assigned to Maxim Integrated Products, Inc., San Jose, CA (US)
Filed by Maxim Integrated Products, Inc., San Jose, CA (US)
Filed on Apr. 12, 2021, as Appl. No. 17/227,899.
Claims priority of provisional application 63/027,295, filed on May 19, 2020.
Prior Publication US 2021/0367566 A1, Nov. 25, 2021
Int. Cl. H03F 3/217 (2006.01); H03K 5/24 (2006.01); H03F 1/02 (2006.01)
CPC H03F 3/217 (2013.01) [H03K 5/24 (2013.01); H03F 2200/03 (2013.01); H03F 2200/171 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A BD modulator for an audio amplifier comprising:
an amplifier assembly configured to receive an analog audio signal having a first voltage and to furnish differential first and second modulation signals, the first modulation signal having a second voltage and the second modulation signal having a third voltage;
a waveform generator for generating a waveform signal having a fourth voltage centered on a common mode voltage; and
a comparator assembly configured to receive the waveform signal and the first and second modulation signals and to provide respective differential first and second quantized signals, each of the first and second quantized signals having a common mode duty cycle,
wherein at least one of the fourth voltage or the second and third voltages are increased or decreased when the first voltage is below a threshold voltage to shift the common mode duty cycles of the first and second quantized signals so that the common mode duty cycles are one of greater than or less than fifty percent (50%).