US 11,889,280 B2
Filters and filter chains
John P. Lesso, Edinburgh (GB)
Assigned to Cirrus Logic Inc., Austin, TX (US)
Filed by Cirrus Logic International Semiconductor Ltd., Edinburgh (GB)
Filed on May 20, 2022, as Appl. No. 17/749,603.
Claims priority of provisional application 63/252,291, filed on Oct. 5, 2021.
Prior Publication US 2023/0107777 A1, Apr. 6, 2023
Int. Cl. H04R 3/04 (2006.01); H04R 1/32 (2006.01)
CPC H04R 3/04 (2013.01) [H04R 1/32 (2013.01)] 25 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
an audio input for receiving an input audio signal;
an tuning input for receiving a tuning signal;
a filter chain comprising a plurality of filters for filtering the audio signal to produce a filtered input audio signal, the filter chain comprising:
a first filter module operating at a first sampling rate; and
a second filter module operating at a second sampling rate greater than the first sampling rate,
wherein a phase response of the first filter module is dependent on the tuning input and wherein a magnitude response of the first filter module is substantially independent of the tuning input.