Granted Patent B2

US 12,254,762 · App. 18/095,305 · Granted Mar 18, 2025

Inventors: Anil Lal (Isleworth, GB); Hamid Sepehr (London, GB); Aleksey S. Khenkin (Lago Vista, TX); Filippo Rossi (London, GB); Vadim Konradi (Austin, TX); Marco A. Janko (Austin, TX); Chin H. Yong (Austin, TX); Colin Campbell (Austin, TX)

Assignee: Cirrus Logic Inc.

G08B6/00

Abstract

Claims (30)

1. A method for determining and mitigating over-excursion of an internal mass of an under-damped electromechanical transducer, the method comprising:

transforming an electrical playback signal to an estimated displacement signal;

based on the estimated displacement signal, determining an estimated over-excursion of the internal mass responsive to the electrical playback signal; and

limiting, based on the estimated over-excursion, an electrical driving signal derived from the electrical playback signal and for driving the electromechanical transducer in order to mitigate over-excursion of the internal mass.

2. The method of claim 1 , wherein limiting the electrical driving signal comprises:

applying an excursion threshold to the displacement signal to generate a limited displacement signal; and

transforming the limited displacement signal into the electrical driving signal.

3. The method of claim 1 , wherein limiting the electrical driving signal comprises:

delaying the electrical playback signal to generate a delayed electrical playback signal;

generating a signal gain based on the estimated over-excursion; and

applying the gain to the delayed electrical playback signal to generate the electrical driving signal.

4. A method for determining and mitigating over-excursion of an internal mass of an underdamped electromechanical transducer, the method comprising:

for each of a set of known playback waveforms, determining a transform for each waveform that minimizes over-excursion of the internal mass based on playback conditions;

storing the transforms in memory; and

during runtime and playback of a particular known waveform, apply a respective transform associated with the particular known waveform and based on playback conditions.

5. A system for determining and mitigating over-excursion of an internal mass of an under-damped electromechanical transducer, the system comprising:

an electrical drive-to-excursion model configured to transform an electrical playback signal to an estimated displacement signal; and

an excursion limiter configured to:

based on the estimated displacement signal, determine an estimated over-excursion of the internal mass responsive to the electrical playback signal; and

limit, based on the estimated over-excursion, an electrical driving signal derived from the electrical playback signal and for driving the electromechanical transducer in order to mitigate over-excursion of the internal mass.

6. The system of claim 5 , wherein limiting the electrical driving signal comprises:

applying an excursion threshold to the displacement signal to generate a limited displacement signal; and

transforming the limited displacement signal into the electrical driving signal.

7. The system of claim 5 , wherein limiting the electrical driving signal comprises:

delaying the electrical playback signal to generate a delayed electrical playback signal;

generating a signal gain based on the estimated over-excursion; and

applying the gain to the delayed electrical playback signal to generate the electrical driving signal.

8. A system for determining and mitigating over-excursion of an internal mass of an underdamped electromechanical transducer, the system comprising:

a memory configured to store, for each of a set of known playback waveforms, a transform for each waveform that minimizes over-excursion of the internal mass based on playback conditions; and

a controller configured to, during runtime and playback of a particular known waveform, apply a respective transform associated with the particular known waveform and based on playback conditions.

Assignments (2)

Continuity (2)

References Cited (11)