Crystals voltage in UNO

[vinodkaruvat]

Hello friends,

I had a queer problem. I am just playing around with the arduino Uno board. Was testing the on board crystal(16MHz).
When powered up I can see that it gives a freq of 16MHz. But the peak to peak voltage is abt 200mV.

How is this possible ?
Arduino is 5V. SO it shld be min 5V, right ?


ANy clues pls ?


Vinod.

 

[betwixt]

Three points:

1. It's an oscillator, it may not need full logic levels for the crystal part of it to work.
2. How did you measure the 200mV? You can only do it with a wide bandwidth oscilloscope and high impedance probe.
3. Are you sure whatever you used to measure it didn't load the signal down and make it smaller. The drive level to a quartz crystal is very small so drawing even a small amount of power from it will reduce the level.

Brian.