Device for audio signal processing for a piezoelectric speaker
US10812905B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 2019 |
| Grant date | Oct 20, 2020 |
| Priority date | — |
| Expiry date | Jul 12, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/802
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A device and a method for audio signal processing for a piezoelectric speaker for generating sound waves in the audible wavelength spectrum includes a signal input for a digital audio signal, a digital correction unit for correcting a nonlinearity of the speaker, a digital PWM generator that converts the signal corrected by the correction unit into a pulse-width modulated switch signal, a power stage controllable by the switch signal such that the speaker can be charged with a voltage for deflecting a membrane, and a closed-loop control circuit that feeds the voltage back as a feedback signal, which includes a first signal noise in the audible frequency range. The closed-loop control circuit of the device includes a noise shaping unit in that shifts a noise energy of the first signal noise outside of the audible frequency range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.