US 11,736,093 B2
Identifying mechanical impedance of an electromagnetic load using least-mean-squares filter
Emmanuel Marchais, Austin, TX (US); Pablo Peso Parada, Maidenhead (GB); and Eric Lindemann, Boulder, CO (US)
Assigned to Cirrus Logic Inc., Austin, TX (US)
Filed by Cirrus Logic International Semiconductor Ltd., Edinburgh (GB)
Filed on Oct. 6, 2022, as Appl. No. 17/961,011.
Application 17/961,011 is a continuation of application No. 16/559,238, filed on Sep. 3, 2019, granted, now 11,509,292.
Claims priority of provisional application 62/826,299, filed on Mar. 29, 2019.
Prior Publication US 2023/0030780 A1, Feb. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G06K 9/00 (2022.01); H03H 17/06 (2006.01); H03H 7/12 (2006.01); G06F 3/01 (2006.01); H02N 2/06 (2006.01); G01H 15/00 (2006.01)
CPC H03H 17/06 (2013.01) [G01H 15/00 (2013.01); G06F 3/016 (2013.01); H02N 2/06 (2013.01); H03H 7/12 (2013.01)] 26 Claims
OG exemplary drawing
 
1. Mechanical impedance identity circuitry comprising:
a first input configured to receive a current signal representative of a current associated with an electromagnetic load during driving of the electromagnetic load by a waveform signal or a signal derived from the waveform signal; and
a second input configured to receive a back electromotive force signal representative of a back electromotive force associated with the electromagnetic load during driving of the electromagnetic load by the waveform signal or the signal derived from the waveform signal; and
an adaptive filter to identify parameters of the mechanical impedance of the electromagnetic load, wherein:
an input of a coefficient control for adapting coefficients of the adaptive filter is a first signal derived from the back electromotive force signal; and
a target of the coefficient control for adapting coefficients of the adaptive filter is a second signal derived from the current signal.