Instructables

Making a soundcard - Can I have two separate inputs, using a single PCM2900 chip?


Which pins are inputs?

Can I add another input or two using the same chip?   or do I need another?

I am following this example...         http://www.netams.com/~anton/usb-adc/index.html

Picture of Making a soundcard - Can I have two separate inputs, using a single PCM2900 chip?
Pin 12 and 13 are the left and right stereo inputs.
gmoon2 years ago
The chip has two inputs, which is shown clearly on the link in figure one. And is described on the page:

"After a careful research, a Texas Instruments PCM2900 chip [1] was chosen as a proper converter (fig.1). It has a stereo I/O (only input is used in this project), USB interface and MS Windows drivers already shipped with an OS."

The larger "Reference board circuit diagram" is easier to read. The inputs are VinL and VinR (Voltage input Left, Voltage input Right).

So yes, it has two inputs.
You can't add more inputs to this chip.

You COULD add a multiplexer, but you'd have to switch that with something you can drive via USB, the chip has digital input pins, but not outputs you could've used to operate the MUX

I do not know the chip, but if takes analog, then could a simple op-amp mixer
allow for multiple inputs ? . . . . . A
If you don't want to know WHAT's coming in when, yes, that's true.
Oh