0
\$\begingroup\$

I am relatively new to embedded electrical engineering. Iam attempting to rebuild the Arduino Uno PCB for learning. I am familiar with the Pierce oscillator and LC circuits and some of the math around them.

I noticed on the ATmega328P datasheet that while the Arduino uses a low power crystal oscillator (as shown), to get a more robust clock signal you can use a full swing oscillator

enter image description here

I found the following 16MHz full swing oscillator.

The ATmega328P datasheet suggests that 22pF caps should be used:

enter image description here

It is not clear to me how (if at all) capacitors would be applied. The full swing oscillator data-sheet states that it has a maximum output load of 15pF, however I am unsure how this works into the problem.

Below is a tentative attempt at how one might connect the components. What is the correct configuration and why?

enter image description here

\$\endgroup\$
1
  • 1
    \$\begingroup\$ That makes no sense. You are mixing up between a crystal oscillator modue which outputs a square wave clock and a crystal which needs the oscillator inside the AVR to oscillate. In AVR terminology, the first one is called external oscillator, and the latter is called external crystal, and the external crystal can be used in low-power and full-swing modes. Please clear up what are you intending to do. Right now you have attached an external oscillator like a crystal to the AVR, so it won't work. \$\endgroup\$
    – Justme
    Feb 2 at 7:53
2
\$\begingroup\$

Your confusion comes from the fact that the Abracon ASE module that you’ve chosen is not an oscillator crystal but rather a full-fledged external clock source. In order to use it with your Arduino you’d need to configure it to use an external clock (section 9.8 in your ATmega328P datasheet).

\$\endgroup\$
1
  • \$\begingroup\$ Thanks, this makes sense \$\endgroup\$ Feb 2 at 8:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.