Portable audio device having reduced sensitivity to RF interference and related methods
A portable audio device having reduced sensitivity to RF interference over a predetermined frequency range from an adjacent mobile wireless communications device may include a portable housing, a battery carried thereby, a recharging power input connected to the battery, a digital signal input, and an audio analog signal output. A digital-to-analog converter (DAC) may be carried by the portable housing and powered by the battery for converting a selected digital audio file from a memory into an analog audio signal. An audio analog amplifier may be connected between the DAC and the audio analog signal output. A first RF filter(s) may be connected to the recharging power input, and a second RF filter(s) may be connected to the audio analog signal output, both for reducing RF interference over the predetermined frequency range from the adjacent mobile wireless communications device.
1. An electronic device comprising: a rechargeable battery; a recharging power input coupled to said rechargeable battery; a signal input; a memory coupled to said signal input and configured to store audio files; an audio signal output; audio circuitry coupled to said audio signal output and said memory, and configured to be powered by said rechargeable battery and playback the audio files; at least one first RF filter coupled to said recharging power input; and at least one second RF filter coupled to said audio signal output.
2. The electronic device of claim 1 further comprising at least one third RF filter coupled to said signal input.
3. The electronic device of claim 2 wherein said at least one third RF filter comprises a parallel coupled capacitor.
4. The electronic device of claim 1 further comprising:
an audio input coupled to said audio circuitry; and
at least one fourth RF filter coupled to said audio input.
5. The electronic device of claim 4 wherein said at least one fourth RF filter comprises a series coupled inductor and a parallel coupled capacitor.
6. The electronic device of claim 1 wherein said at least one first RF filter comprises a parallel coupled capacitor.
7. The electronic device of claim 1 wherein said at least one second RF filter comprises a series coupled inductor and parallel coupled capacitor.
8. The electronic device of claim 1 wherein said at least one first and second filters each filters frequencies in a frequency range of from about 30MHz to 6GHz.
9. The electronic device of claim 1 wherein the stored audio files comprise digital stereo audio files.
10. The electronic device of claim 1 further comprising at least one display coupled to said audio circuitry; and at least one user input device coupled to said audio circuitry.
11. An electronic device comprising: a rechargeable battery; a recharging power input coupled to said rechargeable battery; an audio signal output; a memory configured to store stereo audio files; audio circuitry coupled to said audio signal output and said memory, and configured to be powered by said rechargeable battery and playback the stereo audio files; at least one first RF filter coupled to said recharging power input; at least one second RF filter coupled to said audio signal output; a signal input coupled to said audio circuitry; and at least one third RF filter coupled to said signal input.
12. The electronic device of claim 11 wherein said at least one third RF filter comprises a parallel coupled capacitor.
13. The electronic device of claim 11 further comprising:
an audio input coupled to said audio circuitry; and
at least one fourth RF filter coupled to said audio input.
14. The electronic device of claim 13 wherein said at least one fourth RF filter comprises a series coupled inductor and a parallel coupled capacitor.
15. The electronic device of claim 11 wherein said at least one first RF filter comprises a parallel coupled capacitor.
16. The electronic device of claim 11 wherein said at least one second RF filter comprises a series coupled inductor and parallel coupled capacitor.
17. The electronic device of claim 11 wherein said at least one first, second and third filters each filters frequencies in a frequency range of from about 30MHz to 6GHz.
18. A method for making an electronic device comprising: coupling a rechargeable battery to a recharging power input; coupling a signal input to a memory configured to store audio files; coupling an audio signal output to audio circuitry; coupling the audio circuitry to the memory, the audio circuitry configured to be powered by the rechargeable battery to playback the audio files; coupling at least one first RF filter to the recharging power input; and coupling at least one second RF filter to the audio signal output.
19. The method of claim 18 further comprising : coupling at least one third RF filter to the signal input.
20. The method of claim 18 further comprising:
coupling an audio input to the audio circuitry; and
coupling at least one fourth RF filter to the audio input.