Good morning, everyone---
I've designed two versions of a single-supply powered 3875TF setup, and have had no luck getting the chip to output sound.
The power supply outputs a DC voltage when AC is applied to it, with little if any AC at the outputs (haven't looked at the signal with a scope though, so take that as you wish).
Here is a picture of the reference design for a single-supply setup:
I've used this same setup with two exceptions:
-didn't use any of the optional/starred parts
-I used a 56k resistor in place of the 75k resistor because I had one around
Cap values are as stated in the reference design, with a Cs value of 100uF
Here are a few pics of my implementation, power supply first:
I'd appreciate any help you guys can provide! Thanks again.
I've designed two versions of a single-supply powered 3875TF setup, and have had no luck getting the chip to output sound.
The power supply outputs a DC voltage when AC is applied to it, with little if any AC at the outputs (haven't looked at the signal with a scope though, so take that as you wish).
Here is a picture of the reference design for a single-supply setup:
An externally hosted image should be here but it was not working when we last tested it.
I've used this same setup with two exceptions:
-didn't use any of the optional/starred parts
-I used a 56k resistor in place of the 75k resistor because I had one around
Cap values are as stated in the reference design, with a Cs value of 100uF
Here are a few pics of my implementation, power supply first:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I'd appreciate any help you guys can provide! Thanks again.
How much DC? The LM3875 needs > 20 V single supply.strykerhorse said:The power supply outputs a DC voltage when AC is applied to it,
Could you post photos, where the important parts are not hidden in the shade? And maybe a bottom view as well to see, if all connections are in the right place?
Re: Re: single-supply LM3875 design not working
I'm giving it ~45V DC. I'll get more pics up for you momentarily....
pacificblue said:
How much DC? The LM3875 needs > 20 V single supply.
I'm giving it ~45V DC. I'll get more pics up for you momentarily....
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