How to set VF of a LED in LTSpice?

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EngIntoHW

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Hey,

I'm new to LTspice, and would like to set the VF and IF of a LED.
I'd like the LED to be 3.3V @ 20mA rated.

How do you do it, please?

Thanks.

---
Moreover,
When you perform a BIAS Point Simulation, is there a way for LTSpice to show results on the circuit itself, and not on a separated text file?
 
Last edited:
One of the LEDs in the standard library come close...

You can import a spice model for your specific LED, or build your own model, but that requires a detailed knowledge of how Spice models a junction diode.
 

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Thanks!

You know where LED Models can be found on web?

BTW, is it possible to show the voltages and currents on circuit itself?
 
EngIntoHW said:
Thanks!

You know where LED Models can be found on web?
Click to expand...

I have never looked for specific LEDs models. The ones in diode.lib have always been good enough for simple indicators. Generally, there are lots of various models in the FILES section of the Yahoo LTSpice group.

EngIntoHW said:
BTW, is it possible to show the voltages and currents on circuit itself?
Click to expand...
No.
 
Depends on what you are trying to do. For driver circuit simulations I just put a zener diode in with the zener voltage approximating forward bias of the LED. You won't get proper temp dependancy of Vf but for current sourcing driver circuit it doesn't much matter.
 
Could you please recommend your favorite source for learning about using LTSpice?

For example, building models in LTSpice.
Performing different kinds of simulations.

Thank you.
 
Last edited:
EngIntoHW said:
Could you please recommend your favorite source for learning about using LTSpice?

For example, building models in LTSpice.
Performing different kinds of simulations.

Thank you.
Click to expand...

hi,
This pdf may help.
 

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