Over-sampling digital processing path that emulates Nyquist rate (non-oversampling) audio conversion
US9936282B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 14, 2016 |
| Grant date | Apr 3, 2018 |
| Priority date | — |
| Expiry date | Jun 11, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2430/03
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The behavior of a NOS DAC and an analog filter may be emulated by electronic components of an integrated circuit (IC) by upsampling data and applying a digital filter to the upsampled data. For example, the IC may include a zero-order-hold circuit that upsamples data from a first input sample rate to a second, higher input rate. The upsampled data may be passed to an Asynchronous Sample Rate Converter (ASRC) that performs further upsampling (e.g., from 8*Fs-64*Fs). The upsampled data may be passed to a digital low pass filter. The digital low pass filter may emulate, for example, a response of a fifth order Butterworth analog filter to mimic the effect of analog processing. The IC may integrate the upsampling circuit, the low pass digital filter, a digital-to-analog converter (DAC) and an amplifier to provide an audio solution for playing high-fidelity music in a mobile device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.