[SOLVED] what is operating gate voltage for n channel mosfet?

[nitishn5]

Read my posts first

All you need to do is use a P channel MOSFET for the switches and drive them with the inverted of logic that you have now.
All your problems would be solved!

 

[crutschow]

that logic not suitable for our application.the condition for our application is both logic outputs get at the same time when the kbt battery goes to ov.

Not sure what you mean by "both logic outputs get at the same time when the kbt battery goes to ov" but, in the circuit you posted, if you:
change the BJT to an NPN,
replace the 3k ohm resistor with a short, and
change both MOSFETs to N-channel, logic-level types, sources as the outputs,
then both MOSFETS will turn on with 5V out of the top MOSFET and 1.2V out of the bottom MOSFET when the input is 0V.

 

[FvM]

Besides possible faults in the schematic, you have the problem that IRLM6402 won't fully turn on with Vgs of -1.2 V.

What's the intended load current?