krazyj
Newbie level 1
dac dspic
I am having some difficulty with this circuit.
My input is an iPod who's signal centers around 0V and swings +/-1V.
The ADC, in this example, is set to 12-bit processing. According to the transfer function and when Vref+ - Vref- = 3.3V, the theoretical ranges for conversion are:
0V - bottom
1.65V - midpoint
3.3V - max
My op amp circuit has been verified to give me a signal that operates in that range.
Now, when I load the chip with this signal, I get crickets out of the DAC. Nothing. No signals at all. I realize it is a differential output and, with a scope, I see nothing and with a differential->single-ended op amp circuit, I also get nothing.
I don't understand. My signal should be in range. My code should work correctly. Therefore, my DAC should output something. Right?
Any suggestions? Here is my schematic:
**broken link removed**
THANKS!
I am having some difficulty with this circuit.
My input is an iPod who's signal centers around 0V and swings +/-1V.
The ADC, in this example, is set to 12-bit processing. According to the transfer function and when Vref+ - Vref- = 3.3V, the theoretical ranges for conversion are:
0V - bottom
1.65V - midpoint
3.3V - max
My op amp circuit has been verified to give me a signal that operates in that range.
Now, when I load the chip with this signal, I get crickets out of the DAC. Nothing. No signals at all. I realize it is a differential output and, with a scope, I see nothing and with a differential->single-ended op amp circuit, I also get nothing.
I don't understand. My signal should be in range. My code should work correctly. Therefore, my DAC should output something. Right?
Any suggestions? Here is my schematic:
**broken link removed**
THANKS!
