Systems and methods for reducing digital interference of external signals

Patent metadata

Field	Value
Publication number	US-9325434-B2
Application number	US-201414276237-A
Country	US
Kind code	B2
Filing date	May 13, 2014
Priority date	May 13, 2014
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A mobile device may include a digital data driver and digital data receiver for communication of digital signals within the mobile device at a selected clock rate. The mobile device may also have a device external for the digital data driver and digital data receiver for communication of external signals, such as radio-frequency signals, to and from the mobile device. To avoid interference of frequency harmonics of a digital signal with such external signals, the digital data driver may be configured to control the digital signal based on the frequency of the external signals, such that interference of the external signal by spectral content of the digital signal is minimized, while maintaining the selected clock rate.

First claim

What is claimed is:

1. A system comprising:
a digital data driver for generating a digital signal for communication to a digital data receiver at a selected clock rate, the digital data driver configured to:
receive an indication of a frequency of an external signal associated with a device external to the digital data driver and the digital data receiver; and
when generating the digital signal, control the digital signal based on the frequency such that interference of the external signal by spectral content of the digital signal is minimized, while maintaining the selected clock rate.

2. The system of claim 1 , wherein the digital data driver controls the digital signal by controlling one or more transitions between logic levels of the digital signal based on the frequency.

3. The system of claim 2 , wherein the digital data driver controls one or more transitions between logic levels of the digital signal by controlling an edge rate of each of the one or more transitions based on the frequency.

4. The system of claim 2 , wherein the digital data driver controls one or more transitions between logic levels of the digital signal by controlling a time at which the one or more transitions occur based on the frequency.

5. The system of claim 4 , wherein the digital data driver is further configured to, based on one or more previous transitions between logic levels of the digital signal, determine the time at which the one or more transitions occur.

6. The system of claim 4 , wherein the system further comprises the digital data receiver, and the digital data receiver is configured to, based on one or more previous transitions between logic levels of the digital signal, determine the time at which the one or more transitions occur.

7. The system of claim 1 , wherein the digital data driver controls the digital signal by controlling an amplitude of the digital signal based on the frequency.

8. The system of claim 1 , wherein the digital data driver and the device are integral to a single mobile device.

9. The system of claim 1 , wherein the external signal is a radio-frequency signal.

10. The system of claim 9 , wherein the radio-frequency signal comprises one of a wireless telephony signal, a Global Positioning System signal, and a Wireless Fidelity signal.

11. The system of claim 1 , wherein the digital data driver is further configured to:
receive an indication of a second frequency of a second external signal associated with the device or a second device external to the digital data driver and the digital data receiver; and
when generating the digital signal, control the digital signal based on the second frequency such that interference of the second external signal by spectral content of the digital signal is minimized.

12. The system of claim 11 , wherein the external signal and the second external signal are wireless telephony signals of the same multi-band telephony system.

13. The system of claim 11 , wherein the digital data driver controls one or more transitions between logic levels of the digital signal by controlling an edge rate of each of the one or more transitions based on the frequency and by controlling a time at which the one or more transitions occur based on the second frequency.

14. A method comprising:
receiving an indication of a frequency of an external signal associated with a device external to a digital data driver and a digital data receiver, wherein the digital data driver is configured to generate a digital signal for communication to the digital data receiver at a selected clock rate; and
controlling the digital signal based on the frequency such that interference of the external signal by spectral content of the digital signal is minimized, while maintaining the selected clock rate.

15. The method of claim 14 , wherein controlling the digital signal comprises controlling one or more transitions between logic levels of the digital signal based on the frequency.

16. The method of claim 15 , wherein the controlling one or more transitions between logic levels of the digital signal comprises controlling an edge rate of each of the one or more transitions based on the frequency.

17. The method of claim 15 , wherein the controlling one or more transitions between logic levels of the digital signal comprises controlling a time at which the one or more transitions occur based on the frequency.

18. The method of claim 17 , further comprising determining the time at which the one or more transitions occur based on one or more previous transitions between logic levels of the digital signal.

19. The method of claim 14 , wherein controlling the digital signal comprises controlling an amplitude of the digital signal based on the frequency.

20. The method of claim 14 , wherein the digital data driver and the device are integral to a single mobile device.

21. The method of claim 14 , wherein the external signal is a radio-frequency signal.

22. The method of claim 21 , wherein the radio-frequency signal comprises one of a wireless telephony signal, a Global Positioning System signal, and a Wireless Fidelity signal.

23. The method of claim 14 , further comprising:
receiving an indication of a second frequency of a second external signal associated with the device or a second device external to the digital data driver and the digital data receiver; and
controlling the digital signal based on the second frequency such that interference of the second external signal by spectral content of the digital signal is minimized.

24. The method of claim 23 , wherein the external signal and the second external signal are wireless telephony signals of the same multi-band telephony system.

25. The method of claim 23 , wherein controlling one or more transitions between logic levels of the digital signal comprises controlling an edge rate of each of the one or more transitions based on the frequency and controlling a time at which the one or more transitions occur based on the second frequency.

Assignees

• Cirrus Logic Inc

Inventors

• Melanson John L
• Tucker John C

Classifications

• H04B15/04 Primary

  the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder · CPC title

• G05B15/02

  electric · CPC title

• H04B2215/068

  by avoiding a reception frequency range · CPC title

• H04B2215/067

  by modulation dispersion · CPC title

• H04R3/00

  Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) · CPC title