LTSpice parameters for reversed 2N2222

I got a problem to get a proper simulation on LTSpice IV of a circuit illustrated, among others places, at EEVblog #1157, in YouTube. The clamping circuit (schema around 04:10) is effectively working such as shown in the video, but I can't get a "working" (showing clipping) LTSpice IV simulation. I highly suspect that is because I would have to change a default value or two. I would be interested to know which parameter(s) have to be modified, and, if possible, a link to documentation about how I could get more info about these parameters (probably linked to VEB0)

From EEVblog#1157: 



From LTSpice IV:

It is possible too that I did something totally wrong, even so, please, just comment.

Parents
  • +1
    •  Super User 
    on Dec 14, 2018 4:42 PM

    Hello,

    There are two parameters for the BE breakdown. See the help pages of LTspice.

    Example for a 7.5V @1mA reverse BE breakdown voltage.

    BVbe=7.5 Ibvbe=1m

    .model 2N2222 NPN(IS=1E-14 VAF=100 BF=200 IKF=0.3 XTB=1.5 BR=3 CJC=8E-12 CJE=25E-12 TR=100E-9 TF=400E-12 ITF=1 VTF=2 XTF=3 RB=10 RC=.3 RE=.2 BVbe=7.5 Ibvbe=1m Vceo=30 Icrating=800m mfg=NXP)

    The whole ".model ...." is one line.

    Helmut

Reply
  • +1
    •  Super User 
    on Dec 14, 2018 4:42 PM

    Hello,

    There are two parameters for the BE breakdown. See the help pages of LTspice.

    Example for a 7.5V @1mA reverse BE breakdown voltage.

    BVbe=7.5 Ibvbe=1m

    .model 2N2222 NPN(IS=1E-14 VAF=100 BF=200 IKF=0.3 XTB=1.5 BR=3 CJC=8E-12 CJE=25E-12 TR=100E-9 TF=400E-12 ITF=1 VTF=2 XTF=3 RB=10 RC=.3 RE=.2 BVbe=7.5 Ibvbe=1m Vceo=30 Icrating=800m mfg=NXP)

    The whole ".model ...." is one line.

    Helmut

Children