Part Number: LM5050-1-Q1
Hi Team,
I would like to protect my electronic board form reverse polarity using a reverse polarity protection circuit.
The supply is 12V or 24V. Load current is about 35A (current absorbed by DC/DC Boost converter).
For this high-current, I evaluated LM5050-1-Q1 but the selection of the N-channel Mosfet selection is very critical.
For my application I must comply with ISO7637-2 and ISO16950-2 and it's important to fix the Vdss Mosfet:80V-100V
As reported in the datashet, the requirement is:
22mV/I_load <Rds(on)< 100mV/I_load -> 0,62mOhm <Rds(on) < 2.8mOhm
In particuar, at 22mV the N-Mosfet with Rds(on) so low, is very difficult to find and in any case, it would be very expensive.
and so I Would be inclined to use 2 N-Channel Mosfet.
Each mosfet will then be crossed by about 18A -> 1.2mOhm <Rds(on)> 5.5mOhm
It's correct to choose a Mosfet with Rds(on)>1.2mOhm?
For example, I could choose also 4.5Ohm (always less than 5.5mOhm) or 100mV/I-load is a parametr only as guide-line? I dont' undestand the meaning of upper end of the range...
My further doubt is: f you also found me the Mosfet with these characteristics, IC LM5050-1Q1 has tha ability to drive 2 Mosfet?
I think that LM74700 is more suitable (gate drive is powerful).It's correct?
As one of the requirements is to pass the test ISO7637-2 and ISO16950-2 it's correct to use same circuitery of evaluation TIDA-00992 for LM74700? Naturally means TVS and capacitors...
The datashhet of LM74700 provieds 2 different solutions for 12V and 24V supply instead evalution TIDA-00992 provieds only one solution
for which I have the doubt.
Please, let me Know.
Thanks.