For the Analog devices OP amps the IMD is measured by ITU-R method, according MT-053 tutorial (http://www.analog.com/static/imported-files/tutorials/MT-053.pdf), but often in the other OP amps IMD is measured according SMPTE method, when use 60Hz and 7kHz signals combined in a 12 dB ratio. How can I recalculate IMD SMPTE to IMD ITU-R?
And for the AD8007/8008 according the datasheet IMD is 77dBc
( fC = 19.5 MHz to 20.5 MHz, RL = 1 kΩ, VO = 2 V p-p
Third-Order Intercept is 42.5),
but if I calculate in compliance with the MT-053 tutorial:
Why is the difference so big?