Automotive rated power supply reference designs........... - Page 1
Forum section: electronics / projects

author: Smokey
author_rank: Super Contributor
timestamp: September 04, 2022, 09:14:31 pm
content: Post up your favorite reference designs for robust automotive rated power supplies for powering devices and other low voltage system stuff.All the usual automotive requirements apply:*Wide input voltage range*High voltage transients*Noise*Environmental issues (temp, humidity, vibration)*etc.It seems some of the manufacturer designs are missing what appears to be important protection features.I'm interested to see if anyone knows of a reference design they would consider complete and production ready.Here are some:https://www.ti.com/tool/TIDA-01412https://www.ti.com/lit/ug/tiduc53/tiduc53.pdfOther Similar EEVBlog Threads:https://www.eevblog.com/forum/beginners/powering-electronics-with-12v-in-car-protection

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 05, 2022, 04:23:50 am
content: I mean, I'd have to ask the client if they'll permit release of a partial schematic...But, failing that, a description will suffice for those skilled in the art:In order of appearance:Input: CLC filter (0.1uF, 600R FB, 0.1uF)Input protection: MOV (150V chip)Polarity protection: series diodeAdditional filtering (4.7uF + 0.1R)Overvoltage protection: depletion pass limiter, DN2625K4-G, 40V limitAdditional filtering (600R FB + 4.7uF)SEPIC converter: 14V, couple hundred mA I think?Nominal input 8-60V or something like that; note the voltage limiter pulls in by then, which is fine because of the low current consumption (10s of mA input at that point). Which also makes ride-thru (no load dump switch, just the limiter) feasible.Converter required E-field shield (we used an SMT shield can to be proper) to pass LF near/E-field test (I forget which standard). Passed all other EMC fine, including automotive transients.Tim

author: Smokey
author_rank: Super Contributor
timestamp: September 05, 2022, 08:41:45 am
content: Custom schematics are above and beyond! I was just hoping one/some/most of the component manufacturers actually provided a good reference design or app note. Or maybe there is a good reference design in one of the "power supply cookbook" type books.

author: Smokey
author_rank: Super Contributor
timestamp: September 05, 2022, 08:52:35 am
content: https://www.analog.com/en/analog-dialogue/articles/comprehensive-power-supply-system-designs-for-harsh-automotive-environments.htmlhttps://www.ti.com/lit/an/snva780/snva780.pdf

author: Karel
author_rank: Super Contributor
timestamp: September 05, 2022, 09:45:21 am
content: Automotive 12- and 24-V Battery Input Protection Reference Designhttps://www.ti.com/lit/ug/tiduc41/tiduc41.pdf

author: Smokey
author_rank: Super Contributor
timestamp: September 08, 2022, 07:20:57 pm
content: Quote from: Karel on September 05, 2022, 09:45:21 amCool. That's what I had in mind. Looks like that ticks most of the boxes.

author: Smokey
author_rank: Super Contributor
timestamp: February 14, 2023, 03:31:37 am
content: Interesting graphic on page 3 with the fault conditions and various circuits to address them.https://www.allaboutcircuits.com/uploads/articles/protecting-and-powering-automotive-electronics-systems_compressed.pdf