Aroio HAT masse
Verfasst: 16. Januar 2021, 14:17
Hi,
sorry for the language but I cannot speak German.
A question about Aroio Hat. On the back side of the card there is a jumper connecting DGND (DAC digital section ground) and AGND (DAC analog section ground) and other two jumpers connecting RPI +5V to AVDD (DAC analog section) and DVDD (DAC digital section).
As expected, from my tests, without the jumpers AVDD and DVDD are not connected togather or to RPI +5V, while AGND and DGND seem to be connected togather and to RPI ground inside the Aroio DAC HAT card.
So if you have three different PSU for RPI, digital DAC part and analog DAC part you can just
- take all jumpers away
- power up RPI via the normal USB connector (or through +5V and ground GPIO pins)
- power up the digital DAC section connecting digital PSU +5V to DVDD and digital PSU ground to DGND
- power up the analog DAC section connecting analog PSU +5V to AVDD and analog PSU ground to AGND
Is all this correct?
If this is correct, I cannot understand the reason for the jumper between AGND and DGND: if the two lines are already connected elsewhere, the jumper should not be necessary at all, and possibly build up a ground loop.
Could you please clarify this point?
Thank you in advance
Giorgio
sorry for the language but I cannot speak German.
A question about Aroio Hat. On the back side of the card there is a jumper connecting DGND (DAC digital section ground) and AGND (DAC analog section ground) and other two jumpers connecting RPI +5V to AVDD (DAC analog section) and DVDD (DAC digital section).
As expected, from my tests, without the jumpers AVDD and DVDD are not connected togather or to RPI +5V, while AGND and DGND seem to be connected togather and to RPI ground inside the Aroio DAC HAT card.
So if you have three different PSU for RPI, digital DAC part and analog DAC part you can just
- take all jumpers away
- power up RPI via the normal USB connector (or through +5V and ground GPIO pins)
- power up the digital DAC section connecting digital PSU +5V to DVDD and digital PSU ground to DGND
- power up the analog DAC section connecting analog PSU +5V to AVDD and analog PSU ground to AGND
Is all this correct?
If this is correct, I cannot understand the reason for the jumper between AGND and DGND: if the two lines are already connected elsewhere, the jumper should not be necessary at all, and possibly build up a ground loop.
Could you please clarify this point?
Thank you in advance
Giorgio