I have one last question. As it turns out the AO3400 is not available at digikey. I spoke with them about an alternative PN and they gave me DMN3404LDITR-ND which is similar but has a few differences which I'm hoping you guys can help me understand the repercussions of changing.
A03400 vs. DMN3404L
Drive voltage
2.5V, 10V vs. 3V, 10V
Vgs (th) MAX (I understand this the voltages at which the mosfet will allow current flow but how does this work when it's a ground? Is a positive voltage always applied to the gate to allow current from source to drain? This spec has me a bit concerned (See below)
1.5V @ 250µA vs 2V @ 250µA
Gate charge (I have little understand of this aside from it's the speed at which is switches? But I'm confused with the voltage as they're signifigantly different.)
7nC @ 4.5V vs. 9.2nC @ 10V
Vgs (Max) (I understand this to be max voltage between Gate and source but if it's a ground as a source does this matter?
+/-12V, +/-20V
Input Capacitance
630pF @ 15V vs. 386pF @ 15V
Power dissipation (Not sure if this is an issue but it's half the dissipation of what was in place)
1.4W (Ta) vs 720mW (Ta)
Rds On (Max) @ Id, Vgs (This doesn't seem very significant
26.5 mOhm @ 5.7A, 10V vs 28 mOhm @ 5.8A, 10V
Thanks again and I'll continue to research but maybe you guys could put it in layman's terms for me in the meantime.
Vgs(th) concern
Researching a bit more about threshold voltage I have a concern. The mosfet recommended by digikey (DMN3404L) as a replacement for the AO3200 is different to the point I don't know if it'll work. What is one to do when they don't have any specs to determine what voltage is being sent to the gate? This is what I'm seeing for specs:
Vgs (th) MAX AO3200 vs. DMN3404L min, typical, max
0.65, 1.05, 1.45 vs. 1.0, 1.5, 2.0.
As you can see the typical Vgs (th) of the recommended mosfet is actually ABOVE the MAX for the mosfet that was in there
Dave.