Part Number: TLV320DAC3100
For a small audio player I am developing I would like the user to be able to plug either headphones (stereo) or a passive external speaker (mono) into the same jack. I will sense the impedance/resistance of the connected device with a small test voltage prior to turning on or unmuting either the headphone driver or the class-d amplifier. I will connect the audio output such that they work properly in either configuration (including using a stereo plug for headphones and a mono plug for the speaker.)
That is all fine, but my question is whether there is any problem with the headphone output seeing the the class-d amplifier output, or the class-d amplifier output seeing the headphone output when the other is turned off. (I do not plan to actually switch the output connection, merely turn on the appropriate driver and turn the other one off).
My question: are the HPL/HPR and Class-D output drivers truly high-impedance when powered down? And is there any concern about the powered-down driver seeing the output of the active one when both are connected to the same jack?
