- Sat Feb 06, 2016 9:08 am
#187841
That I can draw with Eagle without problems. But in this way you have no "guard ring". :think:
Honestly I don't know what is the best design. By googling one can find many different design and many different opinions about the argument.
Until now I found different ideas:
1. no separated ground plane at all;
2. separated ground plane only
3. guard-ring + separated ground plane
4. guard-ring only
Until now the best design example I've found is this one (jump to paragraph 7.1 - page 30):
http://www.st.com/web/en/resource/techn ... 221665.pdf
The solution #4 is quite common, it means that an empty region is leaved under the oscillator and caps. Somebody argues that any kind of ground plane under the oscillator will add capacitance effects even if the plane is grounded somewhere.
:think:
Honestly I don't know what is the best design. By googling one can find many different design and many different opinions about the argument.
Until now I found different ideas:
1. no separated ground plane at all;
2. separated ground plane only
3. guard-ring + separated ground plane
4. guard-ring only
Until now the best design example I've found is this one (jump to paragraph 7.1 - page 30):
http://www.st.com/web/en/resource/techn ... 221665.pdf
The solution #4 is quite common, it means that an empty region is leaved under the oscillator and caps. Somebody argues that any kind of ground plane under the oscillator will add capacitance effects even if the plane is grounded somewhere.
:think: