Time delay in digitally oversampled sensor systems, apparatuses, and methods
Systems and methods are described to time delay a signal output from an analog-to-digital converter (ADC). The ADC includes a digital sensor responsive to an analog field quantity. The digital sensor is configured to output an oversampled digital output signal at a sampling clock frequency. A time delay element is configured to receive as an input, the oversampled digital output signal and to output a time delayed oversampled digital output signal. A filter is configured to receive as an input the delayed oversampled digital output signal. The filter low pass filters and decimates to a lower sample rate the delayed oversampled digital output signal. An output includes a low pass filtered decimated delayed digital output signal, where the lower sample rate is less than the sampling clock frequency.
1. A system to time delay a signal output from an analog-to-digital converter (ADC), comprising:
a first integrated circuit die, the first integrated circuit die further comprising:
a digital acoustic sensor responsive to an analog field quantity, the digital acoustic sensor is configured to output an oversampled digital output signal at a sampling clock frequency; and
a time delay element, the time delay element is configured to receive as an input the oversampled digital output signal and to output a time delayed oversampled digital output signal.
2. The system of claim 1 further comprising:
a second integrated circuit die, the second integrated circuit die further comprising:
a filter, the filter is configured to receive as an input the time delayed oversampled digital output signal, the filter to low pass filter and to decimate to a lower sample rate the time delayed oversampled digital output signal and to output a low pass filtered decimated delayed digital output signal, wherein the lower sample rate is less than the sampling clock frequency.
3. The system of claim 2 , wherein the digital acoustic sensor utilizes a sigma-delta modulator and the oversampled digital output signal is a pulse density modulated (PDM) signal.
4. The system of claim 2 , wherein the oversampled digital output signal is a pulse density modulated (PDM) signal.
5. The system of claim 2 , wherein the digital acoustic sensor is a digital microphone.
6. The system of claim 5 , wherein the digital microphone utilizes a micro-electromechanical systems (MEMS) sensor.
7. The system of claim 2 , wherein the analog field quantity is an acoustic pressure field.
8. The system of claim 7 , wherein a time delay applied by the time delay element is an integer number of sample clock cycles.
9. The system of claim 8 , wherein the integer number of sampling clock cycles is selected from a range of one to the sampling clock frequency divided by a baseband sample rate.
10. The system of claim of claim 4 , wherein the filter is a PDM receiver.
11. A system to time delay a signal output from an analog-to-digital converter (ADC), comprising:
a first integrated circuit die, the first integrated circuit die further comprising:
a digital acoustic sensor responsive to an analog field quantity, the digital acoustic sensor is configured to output an oversampled digital output signal at a sampling clock frequency; and
a second integrated circuit die, the second integrated circuit die further comprising:
a time delay element, the time delay element is configured to receive as an input the oversampled digital output signal and to output a time delayed oversampled digital output signal.
12. The system of claim 11 , the second integrated circuit die further comprising:
a filter, the filter is configured to receive as an input the time delayed oversampled digital output signal, the filter to low pass filter and to decimate to a lower sample rate the time delayed oversampled digital output signal and to output a low pass filtered decimated delayed digital output signal, wherein the lower sample rate is less than the sampling clock frequency.
13. The system of claim 12 , wherein the digital acoustic sensor utilizes a sigma-delta modulator and the oversampled digital output signal is a pulse density modulated (PDM) signal.
14. The system of claim 12 , wherein the oversampled digital output signal is a pulse density modulated (PDM) signal.
15. The system of claim 12 , wherein the digital acoustic sensor is a digital microphone.
16. The system of claim 15 , wherein the digital microphone utilizes a micro-electromechanical systems (MEMS) sensor.
17. The system of claim 2 , wherein the analog field quantity is an acoustic pressure field.
18. The system of claim 17 , wherein a time delay applied by the time delay element is an integer number of sample clock cycles.
19. The system of claim 18 , wherein the integer number of sampling clock cycles is selected from a range of one to the sampling clock frequency divided by a baseband sample rate.
20. The system of claim of claim 4 , wherein the filter is a PDM receiver.