I'm really considering this device (Si5351A) to be the VFO and BFO for my new transceiver (Trevo).
I implemented some code, on the Arduino, to change frequency depending on the position of a potentiometer since I'm waiting some rotary encoders to arrive.
While I don't proceed with more code, started to investigate the best way to interface the output to an ADE-1 mixer since I'm using them on the "Trevo".
Saying that: connected the oscilloscope probe to one of the Si5353 outputs and started measuring:
Unload (or for that mather loaded with the scope probe) I got around +19dbm.... _if_ the voltage was applied on a 50 Ohm load (measured 2 V on the scope).... that looks promising...., let's try loaded... and it drops to the following values and matching load (a carbon resistor was used):
47 Ohm: 316 mV
100 Ohm: 700 mV
220 Ohm: 1V
That sayd then the output impedance is 220 Ohm, not even a calculator is needed...
The stated datasheet impedance, for the Si5351, is 85 Ohm, I might be doing something wrong or not taking in account something else... I might try again with the probe in 10x to raise the scope loaded impedance.
Anyhow loaded with around 50 Ohm (47) that's still +3 dBm, enough for some more testing ...
Test frequency was 19.100 Mhz,
Have a nice week!