IRF540N vs IRFZ44N Logic Level MOSFET?

[asking]

Hello,

Recently i was surprise to see that IRF540N Easily work @ Logic level with PIC microcontroller. After Reading the Datasheet of both IRF540N and IRFZ44N no major changes were noticed. But still IRFZ44N dont work @ Logic level. can anyone tell me the reason ?

Thanks..

 

[HTA]

Hello,

the required gate threshold of the IRFZ44N could be up to 4V to turn it on. This is outside the logic level for TTL. Anyhow you need 10V min. if you want to achieve a 25A of current. So you need a predriver.

Enjoy your design work!

 

[asking]

Both IRF540N & IRFZ44N have same value of V(GS) in datasheet

VGS(th) Gate Threshold Voltage 2.0 ––– 4.0 V

 

[HTA]

This mean that it is typical between 2V and 4V. So the one you have seems to be on the higher side. If ou have a 5V supply you could add a pull up(what the minimum Iol of the driver.

Enjoy your design workk!

 

[asking]

But howz...its possible ? both having same V(gs) then IRFZ44N works @ 10-12Volt and IRF540N works @ Logic Level 3.3 - 5Volt ? i need to find reason behind it.

 

[HTA]

This is ther difference between the best material and the worst case one. Usually the variation can differ from production lot to production lot. It is like best case and worst case(could be 50%). If you have try other devices you have.

Enjoy your designe work!