• State
  • Replies 4 replies
  • Subscribers 34 subscribers
  • Views 69 views
  • Users 0 members are here
Support feedback
Options
Options
Related

TPD4E02B04: FPGA LVDS protection

WorkerBee
Prodigy 200 points

Part Number: TPD4E02B04
Other Parts Discussed in Thread: DS90LV004, , ESD204, TPD2S017, STRIKE

System: in an industrial setting, older series FPGA (400-600Mbps) => 8 LVDS outputs => .3-1m flex cable => target device.

I have control over the fpga and drivers.  I currently have the fpga directly driving the wires, and i know that it can be done directly as there is a demo board that does this, but in the system we would like to at least have the option to protect the fpga as we've seen damage in the past on similar setups.

I see parts such as ESD204 or TPD4E02B04 seem to target this sort of application, but for significantly more $ i could buffer the signal using a device such as DS90LV004 or DS15BR400TSQ/NOPB

1) I'd like to know how robust the ESD solution is vs the buffer

Space is a concern, we may be able to fit TQFP, but given the choice, the WQFN is preferable

2) for both solutions, what are the recommended solutions for this application (taking into account performance, but also looking at the future as we'll probably have to support and build this board for 10-20 years.  it seems for either of these solutions there are so many similar parts made by TI.  any with footprint compatible parts is helpful.

  • 0
    Prodigy 200 points

    Sorry, the ESD devices I mentioned aren't targeting LVDS, so they wont work well, but I was wondering if there was something like it for LVDS.

  • 0
    TI__Intellectual 1360 points

    Hello, 

    1. The buffer only provides basic assembly-level ESD protection of 2kV HBM. It leaves them vulnerable to external strikes if used alone, but with an external ESD solution, it can provide high level system protection against IEC 61000-4-2 strikes which are 8kV contact and 15kV air. We also have diode options that preserves signal integrity with ultra low capacitance. For specific pricing, I would recommend reaching out to pd_mkt@list.ti.com. 

    2. Diode wise for DS90LV004  I'm not sure we have a solution with a low enough clamping voltage. The TPD4E02B04 could work, but you would need to test and see as this has a higher clamping voltage. We have deep snapback releasing next year, but for now this would be the only solution, and it would not even be a guarantee .

  • 0 in reply to Leah Jones
    Prodigy 200 points

    I was hoping for a more actionable response...
    i'm not the expert on TI products, and I did spend a lot of time looking into options, but hoped you would have better recommendations.

    1) the front page of the buffers listed claim 12 and 15kV protection, which is very similar to the external esd solutions you recommend.
    2) how to predict performance comparison between
    2a) TPD4E02B04 buffer
    2b) fpga + TPD2S017 (an ESD solution which references LVDS, is there a better one?)
    2c) TPD4E02B04 + TPD2S017 (if they have similar ratings, does this actually help things)

  • 0 in reply to WorkerBee
    TI__Intellectual 1360 points

    1. These are not comparable. On the buffer that 12kV protection is HBM which is usually to protect during factory assembly and handling and uses a completely different testing method (1.5ohm discharge network vs 330 ohm network and 30A at 8kv). Just the buffer will not allow the surges to be redirected to ground. When a strike hits it can cause permanent damage, overstress, abnormal operation like internal latch up etc. This is where an external diode would be good. https://www.ti.com/lit/sg/sszb130e/sszb130e.pdf?ts=1790684057256 < If you'd like more information. 

    2a) very low capacitance, signal quality would be pretty good. Again, would need to confirm abs max with clamping voltage but this is a good option if protecting from 4-2 esd strikes

    2b) This would be alright, it is a very old part, and I think esd204 would be a better solution with lower cap, lower clamping voltage and will allow for LVDS traces. 

    2c) Stacking these would be unnecessary, whichever one has the lower voltage will trigger and absorb 100% of the strike either way. 

    Does this clear some things up? Let me know if you have any more questions.