What is the headphone input/output circuit?

[mjg]

I want to interface my cards headphone jack to a ham radio using the radio's microphone, and sending the headphone output to the radio's microphone input. I don't want to unnecessarily add lots of protection components if they are already present on the board! Hence my question.

Of course, if you want to publish the whole schematic, I'd be happy with that, as I wouldn't need to ask again if I want to use the line IO for either this or other applications.

Mike

[flatmax]

Hi Mike,

Sounds like a good project !

The mic and headphone circuit can be found on page 60 of the data sheet.

I agree, better to keep extra protection circuitry off your design. If you want any feed back or discussion, please post your proposed circuit here.

thanks
Matt

[mjg]

Thanks Matt - lots of useful info there.

Mike