[Faman2012]

Hi,

I think that your SCR model with two BJT is completely wrong. You can see from the I(R4) vs V(anode) characteristic that I(R4) ranges from positive to negative (and high) values. This can’ t be, because a SCR works alternatively as an open circuit and a diode, depending on the gate voltage and on the voltage applied between the anode and the cathode. I’ve attached a basic SPICE cirduit model of a SCR with two ideal BJT.

Below the anodic current and the current vs anodic voltage characteristic.

It can still be improved by introducing the capacitances beetwen Q1 base and emitter, Q1-Q2 bases, and Q2 base and emitter.

[Faman2012]

Sure. You can download from the CadSoft website an Eagle-LTspice IV interface that let you export LTspice IV data into Eagle and vice versa.

[Faman2012]

Hi,
I don’t think that you can import a LTC device model, because they should be encrypted. Every way, since
you have available the working model, design the circuit with LTspice IV.
LTC3108 is well documented for your goal.

[Author]

Posts