CDCE62005 LVCMOS TERMINATION PROBLEM

Rolan Tang

Other Parts Discussed in Thread: CDCE62005

THE Application Report SCAA096 tell us when the ref input and output is LVCMOS, a 1K pull up resistor and 1K Pull down resistor are used, I wonder if they are really needed? I think series resistor is more improtant.

over 15 years ago

0 Sid over 15 years ago

Genius 4530 points

Hi Rolan,

Termination resistors are of 2 types - series termination and parallel termination.

You can use series termination too (I have used it successfully in one of my projects).

But the circuit suggested in AN is not a combination of pull-up and pull-down, it is a parallel termination circuit whose equivalent circuit corresponds to resistance equivalent to that in case of series termination. (Although, I am not sure about the value variation, probably 100E would be better)

Hope this helps.

Regards,

Sid

0 Rolan Tang over 15 years ago in reply to Sid

Prodigy 100 points

Sid, you mean you use series resistance successfully with cdce62005 LVCMOS INPUT/OUTPUT?

T&R,

Rolan

0 Sid over 15 years ago in reply to Rolan Tang

Genius 4530 points

Yes Rolan,

I have used series termination successfully on bot LVCMOS input & output.

Havent faced any problems till now :)

Regards,

Sid

0 Rolan Tang over 15 years ago in reply to Sid

Prodigy 100 points

Thanks a lot! Rolan

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CDCE62005 LVCMOS TERMINATION PROBLEM