This circuit is part of the pulse train FM Detector of a project of mine. It is (part of) an existing circuit which works fine. I modeled the circuit in LTSpice and noticed that the base current is reversed during a large part of the time the transistor is in saturation. It is during the time from 700ns to 1000ns in the model.
I have not observed the reversed base current in the physical circuit yet, but that's mainly because this part of the circuit is a bit hard to desolder and adapt for the current measurement. For the rest the model seems to match the physical circuit very good.
Can anyone explain this reversed base current? I cannot find any explanation of saturated common base BJT's with reversed base current.
Cheers, Koen
I have not observed the reversed base current in the physical circuit yet, but that's mainly because this part of the circuit is a bit hard to desolder and adapt for the current measurement. For the rest the model seems to match the physical circuit very good.
Can anyone explain this reversed base current? I cannot find any explanation of saturated common base BJT's with reversed base current.
Cheers, Koen
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