Hi, I have three questions about ADuM 3440 Propagation Delay.
1. The "units" means different channels of different ADuM3440( eg: between ch1 of one ADuM3440 and ch2 of the other)
2. Yes, tPSKCD is the propagation delay between any two channels of a given ADuM3440.
3. tPSK and tPSKCD are tested when ADuM3440 is powered up, the specs are guaranteed under test environment such as "TA = 25C, VDD1 = VDD2 = 5 V"
We recommend you to use ADuM140E instead of ADuM3440 for your new design. ADuM140E has better perfomance than ADuM3440 such as wider supply voltage range / higher CMTI / lower prop delay / higher operating temp.