cdcun1208lpevm lvcmos output

Jackie Huang

Other Parts Discussed in Thread: CDCUN1208LP

Hello,

We just bought an evaluation board for cdcun1208lp clock fanout buffer. I'm testing it in LVCMOS on IN1p to LVCMOS out on Y1p, Y1n, Y2p, and Y2n. VDD and VDDO# are all configured to 1.8V. I'm getting -0.9 to 0.9 V output, instead of 0 V to 1.8V. How could I get 0-1.8V from the board?

Thanks,

Jackie

over 12 years ago

0 Alan O over 12 years ago

TI__Mastermind 32575 points

The output is likely AC coupled on the eval board. This is done to make the output safe to test with RF test instruments which may not like DC offset voltage. You can replace the AC coupling cap with 0 ohm resistor if you want LVCMOS levels.

Regards,

Alan

0 Jackie Huang over 12 years ago in reply to Alan O

Prodigy 20 points

Makes sense. Rookie mistake, sorry! I removed AC coupling caps on both the input and the output, LVCMOS in -> LVCMOS out works as expected now.

thank you for the help!

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cdcun1208lpevm lvcmos output