The formula is correct. There is small typo in the formula. p=I^2R =( Vx/sqrt(2)Z)^2 R. but z = 1/WC w= omega here.
substituting w = 2pifc we will get the 2 in numerator.
Please check the drive level using the formula for the crystal which is being used in the HX2VL .
This is the Part we use in the DVK:
Part no : ECS-120-20-4 (http://www.mouser.com/ds/2/122/ecs_hc_49us-543840.pdf)
Thank you for your reply. I think you are saying that the final formula is correct, but that the intermediate step should have shown the sqrt(2). Is that what you're saying?
If the formula is correct, is there something wrong with my calculation, which resulted in 1.2 mW?
Second, the crystal you are using in the DVK is a 500 uW max. crystal, which is less than the 600 uW from the Guide and less than the number I calculated. I am happy to use a 500 uW crystal, but I want to make sure the formula matches.