Propagation Delay calculation

[mishrashashi]

I'm analysing DDR3 signals. In data sheet i found two terms
Internal READ command to first data (tAA)= 13.75 – ns
ACTIVATE to internal READ or WRITE delay time (tRCD) 13.75 – ns

does both are related to propagation delay? Plz help

 

[sudhagar124]

Hi Shashi,

I guess you are talking about FLIGHT DELAY.Not sure though...

Regards,
Sudhagar

 

[Airbag79]

Best way to get propagation delay is unwrap the phase of S21 (Insertion Loss) and plot the flight time. Otherwise, it is Speed of light divided by the square root of the effective permitivity of the transmission line/material. Keep in mind effective Dk of vias can be 2-3 x slower than stripline/microstrip.