Timeline for Digital input to mobile phone headset port?
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 2, 2012 at 1:02 | vote | accept | hotpaw2 | ||
| Feb 2, 2012 at 1:02 | history | bounty ended | hotpaw2 | ||
| Jan 31, 2012 at 19:26 | comment | added | Olin Lathrop | @hotpaw2: It shouldn't. It will keep the mic input within a few mV of ground, which should do it no harm. Someone mentioned that this mic input may try to provide power for electret mics. Even so, bringing it to ground should not harm it. You can put a cap in series, but it has to be large enough for the lowest frequency and the unknown impedance of the mic input. For example, at 300 Hz and assuming the mic input has 100 Ohm impedance (shouldn't be that low), you would need at least 5.3 uF. A small 10 uF 10 V or so ceramic should do it. Try without first, though. | |
| Jan 31, 2012 at 19:11 | comment | added | hotpaw2 | @Olin L : With your circuit, the mic input will see a fairly low impedance. Could this cause any issues? | |
| Jan 30, 2012 at 12:49 | comment | added | Olin Lathrop | The circuit with the values as I show it will start rolling off low frequencies around 34 Hz and high frequencies around 16 kHz. Not only is that well beyond the OP's spec by significant margin, it is plenty good enough for all but the most demanding audio. A typical phone isn't going to reproduce that frequency range. Physical size alone guarantees 34 Hz is not a limiting factor. | |
| Jan 30, 2012 at 10:09 | comment | added | Ktc | This is a simple, low cost circuit. It works almost always, it will attenuate some 60dB. You asked for 300 to 3KHz but if you use a lower frequency such as 30Hz etc, the attenuation would be greater and hence your system will probably end up not working. | |
| Jan 26, 2012 at 13:19 | history | answered | Olin Lathrop | CC BY-SA 3.0 |