A problem in the high-frequency equivalent circuit of transistors

msddw

A problem in the high-frequency equivalent circuit of transistors [Copy link]

Why is the current passing through rb'e in the high-frequency equivalent circuit of the transistor Ib? Shouldn't it be Ie? Which expert can answer this question? Thank you all.

S3S4S5S6

The rbc is too large, and the IE cannot flow through it. The analog electronics book has a description of this. Please read it carefully.

wenyangzeng

IE=IB+IC

msddw

S3S4S5S6 posted on 2019-4-22 18:18 The rbc is too big, and the IE cannot flow through it. It is mentioned in the analog electronics book, please read it carefully

How can it be enlarged if it cannot flow through? Won't it not work properly? I still don't understand

S3S4S5S6

msddw posted on 2019-4-22 20:52 How can we amplify it if it can't flow through? Wouldn't it not work properly? I still don't understand

Then wouldn't the amplification factor β be useless?

xiaxingxing

It can be seen that this is the small signal model of the common emitter amplifier circuit transistor.