公开(公告)号：US10566962B2

公开(公告)日：2020-02-18

申请号：US15916708

申请日：2018-03-09

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Toru Ido

IPC: H03K7/08 ,  H03F3/217 ,  H03M1/82

Abstract: This application relates to digital PWM modulation. A PWM modulator (400, 1100) has a PWM generator (402) configured to receive pulse width data (PWidth) and to output a PWM signal (SPWM) comprising a plurality of repeating PWM cycle periods, in which the duration of any pulse of the PWM signal in each PWM cycle period is based on the pulse width data. The PWM generator is configured to synchronise the PWM cycle periods, and the start and end of any PWM pulse, to a received first clock signal. The PWM generator is operable to generate pulses that have a positional error from a centred position within the PWM cycle period and a pulse position controller (403) is configured to control the position of a pulse in a PWM cycle period so as to at least partly compensate for the positional error of one or more preceding pulses.

公开(公告)号：US10070223B2

公开(公告)日：2018-09-04

申请号：US15628057

申请日：2017-06-20

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso ,  Emmanuel Philippe Christian Hardy ,  James Thomas Deas ,  Toru Ido

IPC: H04R3/06 ,  G01D5/244 ,  G01P15/125 ,  H04R19/00 ,  H03M1/06 ,  H03M3/00 ,  H04R19/04 ,  G01D5/24 ,  G01D3/02 ,  H04R29/00 ,  H03M1/12 ,  G01P15/08

Abstract: This application relates to circuitry for processing sense signals generated by MEMS capacitive transducers for compensating for distortion in such sense signals. The circuitry has a signal path between an input (204) for receiving the sense signal and an output (205) for outputting an output signal based on said sense signal. Compensation circuitry (206, 207) is configured to monitor the signal at a first point along the signal path and generate a correction signal (Scorr); and modify the signal at at least a second point along said signal path based on said correction signal. The correction signal is generated as a function of the value of the signal at the first point along the signal path so as to introduce compensation components into the output signal that compensate for distortion components in the sense signal. The first point in the signal path may be before or after the second point in the signal path. The monitoring may be performed in an analogue or a digital part of the signal path and in either case the modification may be applied in an analogue or a digital part of the signal path.

公开(公告)号：US10045124B2

公开(公告)日：2018-08-07

申请号：US15380463

申请日：2016-12-15

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso ,  Toru Ido

IPC: H04B15/00 ,  H04R3/12

Abstract: This application describes methods and apparatus for mitigating the effects of crosstalk in multichannel audio. An audio driver circuit (200) for driving first and second audio loads (103) having a common return path (RC), has first and second signal paths (Left and Right). A crosstalk compensation block (205) is configured to add a first compensation signal to the first signal path and add a second compensation signal to the second signal path. The first compensation signal is generated based on the second audio signal and a first compensation function and the second compensation signal is generated based on the first audio signal and a second compensation function. Each of the first and second compensation functions is based on a predetermined impedance value for at least part of the common return path (RH1) and is also based on a determined DC impedance value (ZL, ZR) for one of the first and second audio loads which is modified by a band correction factor (γ). The band correction factor modifies the DC impedance value so it is a better estimate of impedance across the frequency band of interest.

公开(公告)号：US09716945B2

公开(公告)日：2017-07-25

申请号：US14787052

申请日：2014-04-23

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： John Paul Lesso ,  Emmanuel Philippe Christian Hardy ,  James Thomas Deas ,  Toru Ido

IPC: H04R19/00 ,  H04R3/06 ,  G01D5/244 ,  G01P15/125 ,  G01D5/24 ,  H03M1/06 ,  H03M3/00 ,  H04R19/04 ,  H04R29/00 ,  G01P15/08 ,  G01D3/02 ,  H03M1/12

CPC classification number: H04R3/06 ,  G01D3/02 ,  G01D5/24 ,  G01D5/24476 ,  G01P15/125 ,  G01P2015/0865 ,  H03M1/0609 ,  H03M1/12 ,  H03M3/352 ,  H03M3/458 ,  H04R19/005 ,  H04R19/04 ,  H04R29/004 ,  H04R2201/003 ,  H04R2499/11

Abstract: This application relates to circuitry for processing sense signals generated by MEMS capacitive transducers for compensating for distortion in such sense signals. The circuitry has a signal path between an input (204) for receiving the sense signal and an output (205) for outputting an output signal based on said sense signal. Compensation circuitry (206, 207) is configured to monitor the signal at a first point along the signal path and generate a correction signal (Scorr); and modify the signal at at least a second point along said signal path based on said correction signal. The correction signal is generated as a function of the value of the signal at the first point along the signal path so as to introduce compensation components into the output signal that compensate for distortion components in the sense signal. The first point in the signal path may be before or after the second point in the signal path. The monitoring may be performed in an analogue or a digital part of the signal path and in either case the modification may be applied in an analogue or a digital part of the signal path.