2N2222A CE reverse breakdown characteristics

[jayanthd]

I am trying to plot the reverse breakdown characteristic for a CE 2N2222A transistor. Vcc is 80V and Ib is 0uA. I am inceasinf Vcc in steps of 10V in the DC sweep and trying to plot Ic, but I am not getting the avalanche breakdown curve at Vcc > 75V. The base is open and I am providing 0 to 80V for Vce but the breakdown never happens in the graph.

[Fernando_D]

Hi there,

Could you please attach your circuit for troubleshooting?

Regards,

[johnsold]

I am not sure what model you are using but the ON Semiconductor Spice3 model for that device has nothing in it which models the breakdown charcteristics.

Roberts and Sedra in SPICE, Second Edition, show the large signal model used for DC analysis of the BJT as consisting of two linear current controlled voltage sources and three resistors.

None of the 40 parameters which can be set for a BJT model set a breakdown voltage.

Using a simple test circuit consisting of a ramping voltage source, series collector resistor, and the transistor with open base, the collector voltage will ramp up to 1000 V while the source current (after a transient to charge the capacitances) goes to about 120 nA.  The resistor would limit short circuit current to 10 mA.

Lynn

[jayanthd]

I am attaching my design file. I need reverse breakdown charateristics of the BJT i.e., when Ib = 0 and VCE is > 75 for 2N2222A the base-collector junction has to conduct max Ic.

[Fernando_D]

Hello,

I used the IV Analyzer instrument to plot the collector characteristic curves of the transistor and here is what I got:

As you can see in the simulation parameters, the instruments sweeps from 0 V to 100 V (VCE) and 0 mA to 10 mA (IB). IB=0 is very small, that's why you can't see it here.

Hope this helps.

[jayanthd]

Thank you I will try it and let you know.

[jayanthd]

How to open Simulate Parameters Dialog box? I can't find it.

[Fernando_D · Accepted solution]

Place the IV Analyzer instrument and open its front panel. Then click on the Simulate param button to open the Simulate Parameters window.

Regards,

[jayanthd]

I got it. Thank you. I didn't get the graph you showed after simultion but after changing the values with the values you have used after simulation I got the graph that you have shown. See attached video. I need to set the values after simulation to get the proper graph.

[Fernando_D]

Hello,

Nice to hear to you could plot those curves.

Have a great day,