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I am designing a circuit for a automotive application that requires a stable regulated 12V supply. The supply in turn must be powered by an automotive battery.

I am currently looking at using a automotive-rated buck-boost converter such as the TPS552882-Q1 as my 12V supply source. My question is would the converter by itself already handle any under/over voltage conditions? For example, the converter linked is rated between 2.7V and 36V which covers the range of typical automotive conditions.

Is the buck-boost enough or do I need to pursue additional mitigations such as TVS's, crowbar, or other related circuit-protection devices? If so, why are these additional mitigations needed?

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  • \$\begingroup\$ Personal or commercial product? Also, although more recent vehicles often include circuitry to reduce the impact of load dumps, older vehicles do not. And these can well exceed 100 V. \$\endgroup\$
    – periblepsis
    Commented May 9 at 1:23
  • \$\begingroup\$ @periblepsis It is a personal product, but also going into an older vehicle (1989) \$\endgroup\$
    – Jayson Okhman
    Commented May 9 at 4:08
  • \$\begingroup\$ Start with this Wiki page and a quick google search also found this TI pdf appnote. \$\endgroup\$
    – periblepsis
    Commented May 9 at 5:10

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Is the buck-boost enough or do I need to pursue additional mitigations such as TVS's, crowbar, or other related circuit-protection devices? If so, why are these additional mitigations needed?

Short answer: Yes, you need other mitigations. Reason: speed. The buck-boost is too slow to deal with the very fast voltage transients, which are in the nanosecond range.

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  • \$\begingroup\$ I know that TVS's can be good at responding to fast transients. How can I figure out the range of times that my buck-boost can handle to ensure I don't have a gap when selecting a TVS. \$\endgroup\$
    – Jayson Okhman
    Commented May 8 at 18:26
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    \$\begingroup\$ If this is just a personal project then I wouldn't be too concerned. However, if this is a commercial product, then protecting this product from being damaged, or causing damage, or worse: causing harm to a person as a consequence of suffering a foreseeable voltage transient, then you do really need to spend significant design effort on these mitigations. This is beyond the scope of this answer. \$\endgroup\$
    – Fabio Barone
    Commented May 8 at 18:41

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