1. P channel mosfet
2.N chanel mosfet
3.dual P channel mosfet
4.Dual N chanel mosfet
each type could substitute as long as same type even with different marking code.
Easy way to identified look at the end number of marking code .
example :
AO 4433 look at end of marking code number is odd numbers ( 3 )
this is P channel
example : AO 4407 (7) is odd number ,this is P channel too,
they could be substitute each other even different manufacture and code.
Others P chanel examples :
AF 4825-AM 3423-FDS 6679-SI 4835 ETC
Other example : AOD 4466
look at last number of marking code it is even (6) numbers it's mean this is N channel mosfet and they could replace by other N channel even different
manufacture and code .
Others N channel mosfet examples: AO 4800
AO 4474-AP 4232-FDMC8844-SI 4812 ETC
those mosfet identified only for SO8 mosfet.
There are only 3 pcs P channel there ,2 pcs ADP(adapter) fet's and 1pcs Bat (battery)fet .some
motherboard also may have 1 adp Fet,some replace with diodes to supply every adapter supply need.
I call it "VALW MAIN LINE" .from this line Battery ic and dc/dc power supply ic get VCC to powered each ic and this main VALW line also distributed adapterVoltage to every N channel Source ,before they got enable trigger to produced 3 and 5V_ALW......
P-channel mosfet works drain is a input for nagative supply and source is a output for nagative supply ,and it's gate on with nagative volt .same way if you want to drive positive supply from p-channel mosfet then souce is input and drain is output for positive supply .
This is How 2 pcs P chanel replace by 1 Dual P chanel Mosfet
How DC/DC main power supply open/close gate N channel to produce 3V and 5V_ALW and important signal enable/disable function to activate the DC/DC main supply ic (ISL 6237-RT 8206-TPS 51247)
We will also found (SO3) P channel ,(SO8) mean mosfet have 8pin and (SO)3 mean they
have 3 pin.And this (SO3) also have P or N channel type .so be ware if you
want to make replacement .just make sure replace it whit same type .
Other way to Identified for (SO6) and (SO3) Mosfet transistors are by finding the marking code on ic than
browse the data sheet , if they not found get mosfet location code on board than
find on schema by typing marking code to adobe reader search column to look the correct marking code than browsing the datasheet again to get know mosfet type and get substitution...
this is one of sample N channel (SO3) code : 2N7002 -P0603BDG
FDD6685 - SI12301 -TP0610K.
sample datasheet link for N channel (SO3) 2N7002 : http://www.fairchildsemi.com/ds/2N/2N7000.pdf
2
mosfet in one package ,it is a simply vrm switching mosfet circuit in
single mosfet package ,drain connected with diode cathode and source is
connected with anode that how to identified a N-Channel mosfet.
N chanel caracter common base
n channel mosfet logic low (vi) that mean mosfet not close circuit between the drain and source ,v_out you got vdd voltage via resistance . (Hi)
when you apply vi = Hi in N-Channel mosfet ,mean drain to source connected (close circuit) in this case you got v_out source low you can got at v_out .same way in P-channel but gate work reverse as n-channel mosfet work
