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DS26F31MQML-SP: what happens if one drive is shorted

Part Number: DS26F31MQML-SP

Hello,

I am looking at using DS26F31MQML-SP for RS422 communications. We need to be redundant and the current driver we are using has a potential issue where if one drive dies it could kill the whole chip. DS26F31MQML-SP looks very similar in functionality but the question remains that if one drive is shorted or breaks, could it bring the down the whole chip?

Thanks,
Adam

  • Hi Adam,

    One channel being shorted (as this device can handle a short circuit as its required by standard - but a short circuit can cause a junction temperature increase which could cause a failure on the channel if the fault lasts too long) will not affect the other channels as they are separate - with the only shared connected being the internal enable signal as well as VCC/GND. 

    If a short is pushed too long and/or there is a damaging event on one of the channels - how it will affect the other channels really depends on the actual damage caused - but in short yes it could affect other channels.

    1. Bus pin failure could result in essentially shorting VCC, GND, or both to the damaged channel. If it is both the other channels will not work either as there is a low impedance path between VCC and GND.

    2. During a short condition if the junction temperature increases too much (due to short circuit + other drivers current draw) the device can be overheated and damage could occur at multiple points during the fail condition.

    The concern is that damaging 1 channel may result in only those pins being damaged  - but since everything is connected to VCC ground there is always a chance the entire device is affected - and possibly the entire bus depending on failure mode. 

    So there is a decent chance during failure/fault that the entire chip could become damaged depending on specific failure mechanism. 

    Please let me know if you have any other questions!

    Best,

    Parker Dodson