How to get a precise amount of voltage

Community General Discussions
1

Hi guys.

I am working on my ISD4002 chip and i am now going through the recording part. This is what the manual says:

"[...] a 32 mVp-p (peak-to-peak) maximum signal should be capacitatively connected to this pin for optimal sound quality"

anainput.jpg

My question is: how can i be sure the right amount of voltage is gonna enter that ANA IN+ pin? I am also not sure how to measure the source voltage (coming from the "line out" hole from my computer).

2

Hi,I have found a swedish

Hi,

I have found a swedish website. In the schematic a simple potentiometer have been used on ANA IN+. A higher voltage will only result in a distortion of the output signal, it will not kill the chip. I am not shure about the lineout voltage from a soundcard, but I think it can reach 2Vpp.

Hope this will help you.

3

thanks mate, but i also had

thanks mate, but i also had found that site before :slight_smile:

But how can he know that with a 4.7K resistor he will limit without knowing the aumount of current he wants to flow in? What i mean is… i could find out the correct resistor if i also knew the current needed, but without that i don’t know how to get to it.

I am gonna use the 4.7K resistor, but if i don’t find out why i won’t sleep peacefully tonight :D…this happens with every project of mine actually :slight_smile:

4

BTW, what’s that symbol in

BTW, what’s that symbol in the second schematic (the second one in the hardware section) that shows the 4.7K resistor with an arrow pointed to it?

EDIT: sorry, i got it. It was one of my dumb moments