MOSFET gate driver

[electros6]

hi guys , 
             I like to do my own power supply , I built is with precision in the prototype . I used simple transistor amplifier to boost 5V to 15V to drive the mosfet. I need yours suggestion about to amplify the 5V pulse signal of the microcontroller to 15V to drive the mosfet . I don't want any pulse transformer because I control the gate voltage of the mosfet to contol the power supply out  so I want liner variation of my DAC output to be amplified  to drive the MOSFET

[dannyf]

I need yours suggestion about to amplify the 5V pulse signal of the microcontroller to 15V to drive the mosfet . I don't want any pulse transformer because I control the gate voltage of the mosfet to contol the power supply out  so I want liner variation of my DAC output to be amplified  to drive the MOSFET

Maybe you didn't realize this, but you already have it - as you said here:

I used simple transistor amplifier to boost 5V to 15V to drive the mosfet.

What you are contemplating is very rare, for a good reason.

[madires]

What about using a logic level MOSFET?

[dannyf]

From what s/he wrote, s/he is not looking for a gate driver but actually a linear amplifier to drive the gate of a mosfet.

[madires]

From what s/he wrote, s/he is not looking for a gate driver but actually a linear amplifier to drive the gate of a mosfet.

Ah, an OPamp in non-inverting configuration with a gain of 3. But the logic level MOSFET is still an alternative :-)

[Zero999]

I want liner variation of my DAC output to be amplified  to drive the MOSFET

Why?

Could you be using the wrong technology here?

MOSFET drivers are typically switches, like a big logic gate with level shifting up to a higher voltage and higher current capability output. They don't take an analogue signal from a DAC and amplify it to between 0V and 15V. To do that, use a rail-to-rail op-amp configured as a non-inverting amplifier with a gain of 3. If you need a higher output current, you'll need to add a MOSFET to the output of the op-amp but within the feedback loop to boost the current.

[dannyf]

But the logic level MOSFET is still an alternative :-)

Depends on what s/he was trying to do.

Could you be using the wrong technology here?

Sounds like it.

[electros6]

using opamp to drive the mosfet , is it good , is it provide enough current to rice the mosfet

[free_electron]

hi guys , 
             I like to do my own power supply , I built is with precision in the prototype . I used simple transistor amplifier to boost 5V to 15V to drive the mosfet. I need yours suggestion about to amplify the 5V pulse signal of the microcontroller to 15V to drive the mosfet . I don't want any pulse transformer because I control the gate voltage of the mosfet to contol the power supply out  so I want liner variation of my DAC output to be amplified  to drive the MOSFET

SCHEMATIC !

pmos ? nmos ?
if using an nmos you will need to be able to drive above the incoming rail.

in any case you will need a current source or the thing will oscillate like hell.

[calexanian]

Oh heck! Just use an Ignitron to drive the fet..  Once.....   

[kg4arn]

. . . in any case you will need a current source or the thing will oscillate like hell.

@free_electron:  Is this due to the gate capacitance of the MOSFET?