On Thu, May 10, 2012 at 10:45:08AM +0100, Mark Brown wrote: > On Thu, May 10, 2012 at 05:41:15PM +0800, Shawn Guo wrote: > > > The "Mic Bias" here is really a SGTL5000 internal supply. > > If it is then what's providing the bias to the mic? It's common for > chips to have a micbias supply which comes out of the chip and is used > by mics, this is my understanding of what this circuit is. I did not make myself clear, but you made :) Yes, this is exactly the thing on my mind, and the circuit will look like: STGTL5000 BOARD | MIC_IN ---+--- JACK ^ | ^ | | | | | | MIC_BAIS----+-----/ | Isn't you helped me create this understanding? [1] Regards, Shawn [1] http://article.gmane.org/gmane.linux.alsa.devel/96351 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html