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I used this relay driver in a design, but there is no stock anywhere as far as I can find.

I have been looking for similar alternatives, but it seems to be hard to find anything similar even (not necessarily pin-compatible.)

Does anyone have a suggestion for a similar part?

Part numbers of the part that I am using (automotive version etc.)

  • TPL7407LAPWR
  • TPL7407LPWR
  • TPL7407LAQPWRQ1
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  • \$\begingroup\$ "shopping questions" are not allowed on Stack Exchange. \$\endgroup\$
    – user253751
    Aug 13, 2021 at 11:27
  • \$\begingroup\$ I'm not sure if asking for 2nd source is really a shopping question. Especially not if it means re-design to use another part which isn't drop-in replacement. \$\endgroup\$
    – Lundin
    Aug 13, 2021 at 11:35
  • \$\begingroup\$ Anyway, this part is apparently already a drop-in replacement for the classic ULN2003A. So you just need to figure out why exactly you used the supposedly specialized TI part instead of ULN2003A. (I'm guessing crappy reliability in rough environments) Maybe you can use ULN2003A if you patch in some extra protection, like TVS or whatever is needed. \$\endgroup\$
    – Lundin
    Aug 13, 2021 at 11:40
  • \$\begingroup\$ D-K has Nch replacements in stock \$\endgroup\$ Aug 13, 2021 at 11:41
  • \$\begingroup\$ D-K? Nch replacement? sorry I do not follow... link maybe? Yes, ULN looks very simular. Maybe ULN2003AIPWR could work for driver to these relays.. if that would work maybe is the best solution. I hvae not designed original part so I don´t know the reason behind the choice. In what way are ULN bad in rough enviroment? \$\endgroup\$
    – mannen
    Aug 13, 2021 at 12:03

2 Answers 2

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Everyone is dealing with chip shortages right now. It's not just you!
In this case, I would seriously look in to using an appropriately sized transistor and a diode across the relay coils. I regularly drive relay coils (admittedly they are small and low voltage), a circuit like that. (Ignore ALL values in the circuit below. This is a topology-only diagram.)

schematic

simulate this circuit – Schematic created using CircuitLab

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Your choices are to;

  1. look for a substitute
  2. redesign with discretes, or
  3. buy an 8 channel relay card with all the drivers included (cheap)
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  • \$\begingroup\$ The obvious substitute is ULN2003A. Though only the OP can tell if it is good enough for their requirements. The main difference appears to be current consumption - if they can live with a lil extra current, then ULN2003A can be bought anywhere since it's a standard part. \$\endgroup\$
    – Lundin
    Aug 13, 2021 at 11:45

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