Oznog
Active Member
I have an app I want to use a very high current/low rds on N-channel MOSFET. However, for isolation reasons, the intrinsic body diode is going the wrong way and will create problems.
So, recalling that MOSFETs are inherently symmetrical devices, can't I just reverse the source and drain and use it in reverse? What are the consequences of doing so? Does it change the gain or what?
Here's the background: I have a camper van with a secondary deep storage battery, an isolator (they're made of std high current diodes), and a huge 160 amp alternator. The alt's regulator references the main battery voltage. Now the problem is, the secondary battery gets deeply discharged at times, yet the float voltage used by the reg isn't enough for the high charge rate it could make use of, and it takes many hrs to charge. Since the isolator's diode drops about 0.7V (over 1V when high current is involved), I can boost the voltage by bypassing the isolator on the deep cycle's side. I'd use a MOSFET in satuation and some supplemental stuff to turn off the gate when it would drain the battery rather than charging it. However, the intrinsic diode still allows this, so I'd like to reverse it so it's just in parallel with and facing the same way as the isolator's diode.
So, recalling that MOSFETs are inherently symmetrical devices, can't I just reverse the source and drain and use it in reverse? What are the consequences of doing so? Does it change the gain or what?
Here's the background: I have a camper van with a secondary deep storage battery, an isolator (they're made of std high current diodes), and a huge 160 amp alternator. The alt's regulator references the main battery voltage. Now the problem is, the secondary battery gets deeply discharged at times, yet the float voltage used by the reg isn't enough for the high charge rate it could make use of, and it takes many hrs to charge. Since the isolator's diode drops about 0.7V (over 1V when high current is involved), I can boost the voltage by bypassing the isolator on the deep cycle's side. I'd use a MOSFET in satuation and some supplemental stuff to turn off the gate when it would drain the battery rather than charging it. However, the intrinsic diode still allows this, so I'd like to reverse it so it's just in parallel with and facing the same way as the isolator's diode.
