Can't successfully add IRL1404Z to LTSpice

[PickyBiker]

Here is what I have tried:

1. downloaded the simulation file from international rectifier irl1404z.spi (it is a .subckt file, not a .model file)
2. moved it to the same folder as my project
3. inserted an nmos device, M1 into the circuit
4. Named the device type IRL1404Z
5. added .inc IRL1404Z.spi (the system finds the file okay when I run the simulation)
6. Right-clicked the M1 device and changed the Prefix to X
7. When I run the simulation, the error generated is: "Unknown subcircuit called in: xm1 n002 n004 0 irl1404z"

I'm thinking a bad .subckt file, but maybe I am doing something wrong?

I attached the .asc and .spi files. Changed the .spi to .txt so the system lets me upload it.

 

[alec_t]

I'm thinking a bad .subckt file, but maybe I am doing something wrong?

The subckt file is ok. I just copy-pasted the contents directly on to the schematic and it works fine. So your problem is that LTS isn't using the correct path to the file, i.e the file isn't where LTS is looking for it, or the file extension is confusing it. Try changing the extension to .sub or .mod.

 

[audioguru]

Will your simulation show a Mosfet with a range of Vgs that the actual Mosfet has?
Will your simulation show the circuit working fine when the conditions will kill an actual Mosfet?

 

[PickyBiker]

Okay, i changed the .inc to include the complete file pathname and it works. now. Thank you.

audioguru, the IRL1404Z is supposed to handle 140- 200 amps with proper cooling. I'm drawing 30 amps.
The mosfet also has a vgs og +=16v my power source is 12V

Am I not okay with these params?

 

[audioguru]

Your schematic does not show a gate drive pulse voltage so the Simulation and I do not know how well the Mosfet turns on.

 

[PickyBiker]

This is the signal at the gate of M1. Hope that is the information you were looking for .

 

[audioguru]

Your gate pulses have slow rise and fall times probably caused by the very high value of the series gate resistor. Maybe the pulse generating circuit has a low output current requiring the high resistor value?
Can your power supply hold its voltage up when the current is nearing 30A?

 

[PickyBiker]

The power supply is 12v 500 Watt which will easily handle the 30 amps.
You are correct, about the gate resistor. I changed it to 680 ohms and that makes the gate edges nice and sharp and the input pulse current is only 10 ma.

 

[audioguru]

The spec's for the Mosfet you selected will work fine even if the Mosfet has minimum spec's. The simulation shows only a Mosfet with much better "typical" spec's unless you change the spec's manually in the model.

 

[PickyBiker]

Thanks!