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DS25CP152 - Disabled Output

Kawai
Guru 19785 points
Other Parts Discussed in Thread: DS25CP152, DS90CP02, SN65LVCP202, SN65LVCP402

Hi,

Our customer is looking for >1.5Gbps, 2:2 crosspoint switch which have Hi-Z output when the output is disabled.

Could you please tell us if DS25CP152 have Hi-Z output when the output channel is disabled (using EN1/2 pins) ?

I could not find the description in the datasheet.

If DS25CP152 is not Hi-Z output at disabled channel, could you please tell us the part which can achieve this ?

Best Regards,
Kawai

  • 0
    TI__Expert 4400 points

    The DS25CP152 outputs cannot be placed into tri-state mode (high impedance).  The DS25CP152 includes on-chip 100Ω output terminations that are always present, even when the outputs are disabled via the EN1/2 pins.

    The following >1.5 Gbps, 2x2 crosspoint switches have outputs which support tri-state mode:

    • DS90CP02
    • SN65LVCP202
    • SN65LVCP402

    Gary Melchior

  • 0 in reply to Gary Melchior
    Guru 19785 points

    Thank you for the information.

    Please let me ask you a little bit more about these three devices.

    [Question]
    Does DS90CP02 have 100 Ohm input termination ?
    I could not find the desription in the datasheet, so I think you would need external termination.

    [Question]
    How shoud we treat the input pins for the three devices (DS90CP02, SN65LVCP202/402) when the channel is not used ?
    I believe LVDS input can be left open for the unused channels. If you need the fail-safe circuit externally, please tell us.

    Best Regards,
    Kawai

  • 0 in reply to Kawai
    TI__Expert 4400 points

    Correct; the DS90CP02 does not include integrated 100Ω input terminations, so external terminations must be provided.

    Unused inputs may be left open.  These are 2x2 switches, so the unused channels are ignored by the switch settings.  Also, unused outputs on these devices can be independently disabled for power savings, and this will prevent any unwanted noise from unused channels.

    If an unused channel is enabled and there is concern over the possible extra noise or power, external failsafe biasing may be implemented.

    Gary Melchior

  • 0 in reply to Gary Melchior
    Guru 19785 points

    Gary-san,

    I understand.
    Thank you very much.

    Best Regards,
    Kawai