Thread Starter R!f@@ Joined Apr 2, 2009 9,740 Mar 23, 2016 #1 I am planning to use separate Vref with ADC. My question, is should I bypass the Vref+ or not. The Vref will be taken separate from another circuit with jumper wires less than a feet together with ADC which I want to check.
I am planning to use separate Vref with ADC. My question, is should I bypass the Vref+ or not. The Vref will be taken separate from another circuit with jumper wires less than a feet together with ADC which I want to check.
ErnieM Joined Apr 24, 2011 8,089 Mar 23, 2016 #2 Yes, absolutely add bypass, both at the ref source and at the PIC. A bit of series impedance isn't a bad idea either, say 100 ohms to give the cap something to break against. And your oscilloscope will be your friend here for design validation.
Yes, absolutely add bypass, both at the ref source and at the PIC. A bit of series impedance isn't a bad idea either, say 100 ohms to give the cap something to break against. And your oscilloscope will be your friend here for design validation.
Thread Starter R!f@@ Joined Apr 2, 2009 9,740 Mar 23, 2016 #3 OK...a 100nf as the Vref+ to bypass it. I am not sure why a 100R series with the Vref+ Can you explain why.
OK...a 100nf as the Vref+ to bypass it. I am not sure why a 100R series with the Vref+ Can you explain why.
ErnieM Joined Apr 24, 2011 8,089 Mar 23, 2016 #4 It gives the cap something to work against, so the noise stays on the ref side and not on the pic side.
It gives the cap something to work against, so the noise stays on the ref side and not on the pic side.
Thread Starter R!f@@ Joined Apr 2, 2009 9,740 Mar 23, 2016 #5 100R at the Vref+ input side and a 100nf at the Vref+ pin of the PIC
