公开(公告)号：US10116473B1

公开(公告)日：2018-10-30

申请号：US15926395

申请日：2018-03-20

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Pradeep Dhananjay ,  Tejasvi Das ,  Bhupendra Manola ,  Bruce E. Duewer

IPC: H04L25/49 ,  H04L25/03 ,  H04R3/04 ,  H04B14/04

CPC classification number: H04L25/4927 ,  H03F1/0227 ,  H03F1/025 ,  H03F3/187 ,  H03F3/213 ,  H03F2200/03 ,  H03F2200/331 ,  H04B14/046 ,  H04L25/03159 ,  H04R3/04

Abstract: An apparatus may include a delta-sigma modulator for quantization noise shaping of a digital signal, a digital-to-analog converter configured to generate an analog signal from the digital signal, and an amplifier configured to amplify the analog signal and powered from a charge pump, wherein the charge pump is configured to operate at a switching frequency approximately equal to a zero of a modulator noise transfer function of the delta-sigma modulator, such that the impact of charge pump noise on a total harmonic distortion noise of the apparatus is minimized.

公开(公告)号：US10432150B2

公开(公告)日：2019-10-01

申请号：US15993955

申请日：2018-05-31

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Ramya Balasundaram ,  Bhupendra Manola ,  Pradeep Dhananjay

IPC: H03F1/30 ,  H03F3/45 ,  H03F3/187 ,  H03F1/52 ,  G06F3/16

Abstract: An apparatus may include a digital-to-analog converter configured to convert a digital audio input signal into a differential analog input signal with a substantially non-zero common-mode voltage, an amplifier configured to receive the differential analog input signal and generate at an amplifier output a ground-centered output signal from the differential analog input signal, a clamp configured to selectively couple and decouple the amplifier output to a ground voltage, and a controller configured to control the clamp to selectively couple and decouple the amplifier output to a ground voltage responsive to transitions between power states of a device comprising the apparatus and control the differential analog input signal generated by the digital-to-analog converter in order to minimize a level transition current through an output load coupled to the amplifier output during transitions between the power states.