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DS100BR410: Are AC coupling caps on high speed inputs required for operation?

Part Number: DS100BR410

Can anyone tell me if AC coupling caps are required to be used on the high speed inputs to this CML repeater?  The datasheet does not explicitly require them, although I see a cartoon that uses such caps on both the inputs and the outputs of the part.

I am operating at about 1.44 Gbps and am wondering if I should stop and modify a current board fabrication that does not incorporate such AC coupling (or "DC blocking") caps on the high speed inputs.

Thanks.

  • Hi Mark,

    Yes this device does need AC coupling capacitors on the high speed inputs.  I am not sure what is running at 1.44 Gbps, but there should be some encoding or scrambling used to maintain DC balance on the capacitor.  Capacitors are also recommended on the device outputs since the output common mode voltage of ~ 1.1V may not be compatible with the input common mode requirement of the attached Rx.

    Regards,

    Lee