Timeline for Input protection circuit with P MOSFETs and SPDT for ON-OFF switch
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 4, 2017 at 14:15 | vote | accept | KyranF | ||
| Oct 12, 2014 at 17:01 | comment | added | KyranF | I think when fully loaded though, it may be an issue, so i'm looking for sub 20mOhm FETs now :( | |
| Oct 12, 2014 at 16:58 | comment | added | KyranF | I'm trying to find D-PAK package (for size and thermal goodness) components with less than 30mOhm on resistance each, so that the total resistance all the way through to the load/s is less than 100mV for 1A (this is a little above what the actual loads are expected to be). Currently at 1A, the MOSFET i'm looking at using for these pass elements is 36mOhm, so it's fine. | |
| Oct 12, 2014 at 15:37 | comment | added | Asmyldof | @KyranF By the way, are you going for sub-100mV drop in the first PMOST? Because there are schkottky diodes that sport about 100mV at 3A, or maybe even a little less. If that's too much, the MOST it is. | |
| Oct 12, 2014 at 15:35 | comment | added | Asmyldof | @KyranF In principle there's no need for a capacitor, you could possibly put a "cheaper" 100nF for some oscillatory-prevention in there, but the MOSTs should de a fine job without. I do indeed agree with you that a fuse should always be as close to the dangerous object as possible... In this case that being a battery capable of sourcing 10's to 100's of ampere. :-) | |
| Oct 12, 2014 at 15:31 | comment | added | KyranF | Thanks mate, so you suggest keeping the resistors and indeed moving the fuse further up the chain? The capacitor maybe I can avoid, as my buck converter input capacitors will be so close they basically act as the same thing. The NMOS stuff looks cool, but not appropriate for my device. Thanks anyway haha | |
| Oct 12, 2014 at 15:27 | history | edited | Asmyldof | CC BY-SA 3.0 |
added 316 characters in body
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| Oct 12, 2014 at 15:20 | history | answered | Asmyldof | CC BY-SA 3.0 |