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Beginners / Re: LM317 Based Digitally Controlled Power Supply
« Last post by TerrySt on Today at 01:26:33 am »
Hi there,
Actually I was referring to the accuracy of the set point of the voltage that would be controlling the LM317. If the user wanted to output say 5 volts then they would have to apply about 3.75 volts to the ADJ pin. If it was just 3.70 volts then the output would be 4.95 volts. If the design could get that right though (3.75v) I don't think there would be any worry, but that could easily require feedback which brings in the issue of control stability into the picture. If the designer wants to use feedback then it's going to be their responsibility to get it stable. That means the uC will have to sample the output and make adjustments, and that means there will be a delay.
As far as regulating once the right voltage is actually applied, that may be ok but I have not looked into that in detail.
Yep. I hope the OP realizes the issue and has a plan to deal with it.
Terry