• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 729 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Firewire data hot-plug circuit

David Calhoun
Prodigy 10 points

We are building a system which has a IEEE 1394 device connected to our main system through a military style cable bundle.

We intend to turn off the power to the firewire device electronically.

We are concerned that the data lines might still be driving an unpowered device.

Is this an issue?  

Do you have any products which can switch the data lines to a high impedance state so that it is not an issue?

Thanks,

Dave

  • 0
    Guru 316240 points
    Typically, PHYs are designed to be powered from the bus, so that daisy-chaining works even with a powered-off device in the middle.
    But there is no current accidentally leaking from the data lines.

    All PHYs remove the bias voltage from ports in the suspended state.