Hi there,
It's first time I am doing a layout for a dac so I'd like to have you guys check out my pcb.
schematic for reference:
top layer:
bottom layer:
Few comments/questions:
- I've chosen ADP151 for regulators. Is there anything better in terms of output ripple that one can buy in single quantities?
- Enable pins of the regulators are pulled up to the input voltage (hope it's the right way to do it) and are also available on the connectors so that turning off the whole module is possible by shorting them to ground.
- I've separated digital and analog grounds on the pcb and connected them in one spot. Not sure if it's helping, but if it's going to cause grounding problems please let me know Also, charge pump is hooked up to the analog ground. I don't know how fast is it switching but maybe I'm not isolating high speed stuff from the analog part at all.
- Not sure how I should treat digital signals. I've tried to put as much ground plane between them as possible and use plenty of vias to form some sort of shield. Should I make the tracks of equal length?
- I didn't include output filter caps on the pcb cause they will be easy to solder on the output connectors and i don't know yet what kind of caps i want to use.
- The PCB is only 30x40mm so it should make a nice solution for a multi channel interface once the new xmos chips become available (I'm planning to use xs1-s as usb->i2s solution)
As always I am looking forward to your insights and comments.
Michal
It's first time I am doing a layout for a dac so I'd like to have you guys check out my pcb.
schematic for reference:
top layer:
bottom layer:
Few comments/questions:
- I've chosen ADP151 for regulators. Is there anything better in terms of output ripple that one can buy in single quantities?
- Enable pins of the regulators are pulled up to the input voltage (hope it's the right way to do it) and are also available on the connectors so that turning off the whole module is possible by shorting them to ground.
- I've separated digital and analog grounds on the pcb and connected them in one spot. Not sure if it's helping, but if it's going to cause grounding problems please let me know Also, charge pump is hooked up to the analog ground. I don't know how fast is it switching but maybe I'm not isolating high speed stuff from the analog part at all.
- Not sure how I should treat digital signals. I've tried to put as much ground plane between them as possible and use plenty of vias to form some sort of shield. Should I make the tracks of equal length?
- I didn't include output filter caps on the pcb cause they will be easy to solder on the output connectors and i don't know yet what kind of caps i want to use.
- The PCB is only 30x40mm so it should make a nice solution for a multi channel interface once the new xmos chips become available (I'm planning to use xs1-s as usb->i2s solution)
As always I am looking forward to your insights and comments.
Michal