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I'm replacing a stolen PCM4222EVM adc with a PCM4202EVM adc but they left my + -15V, 5V triple-output linear power supply. However, I just discovered that there is a difference in powering the PCM4202EVM in that it also requires an extra DIGITAL 5V supply, so 4 separate power supplies: + - 15V, 5V & 5V Digital.

Being a dolt, can I just solder a wire to my 5V supply and run it to the digital header or do I need to do some kind of decoupling with a capacitor setup? Also, what would I do with the grounds?

I may replace the triple-linear with a triple-switching supply if that makes any difference with adding the 5V digital. Both would supply adequate current for the dual 5V draw btw.

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  • \$\begingroup\$ What does the EVM manual say how to connect it? \$\endgroup\$
    – Justme
    Jan 24, 2021 at 19:44
  • \$\begingroup\$ Since it doesn't sound like you're too worried about efficiency, and the datasheet calls for a maximum of 200mA at 5v, I would consider just sticking two linear 5v regulators on the +15 rail and generating independently regulated +5v supplies so that you didn't need a three rail power supply. \$\endgroup\$ Jan 24, 2021 at 20:22

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Yes, ground connection of +15/-15 and +5 supply would be a concern.
partial schematic PCM4202EVM The two analog gnd and digital gnd are connected on the EVM board. I would want the digital supply to be independent of the analog supply, so that their grounds connect at only one spot: on the EVM board.

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  • \$\begingroup\$ Thanks to all for the replies. It appears that I should add a separate 5V power supply to my triple-output supply case, and since I used an umbilical cable with a couple of unused wires from it to the converter I was thinking of just repurposing a 5V phone charger that has at least half an amp per spec requirements, and it would be invisible and look clean. Is there an issue with using a phone charger for my digital 5V supply? \$\endgroup\$
    – RicBubJul
    Jan 25, 2021 at 3:28

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