Alundra81
Newbie

Hello, I'm an electronic engineering student. I'm trying to solve this exercise but
it's too difficult for me:

I do not understand elementary stages and how they work
Help me please
I think:
Q3 is a current generator (transistor connected diode like)
Q2 is a common base amplifier because the base is connected to ground for the signal
Q1 is a common base amplifier because the base is connected to ground. It takes the input signal from Q2 collector.
Q4+Q5 looks like a Sziklai Pair.
Is this correct? Maybe Q1+Q2+Q3 form a canonical amplifier + active load and I don't realize that!
How those stages work togheter?
The homework requires to find the continuous value of VI that corresponds to Vo=0.
But, supposing all transistor on active region:
VC3=-Vcc+VBE3=5-0.7=4.3 V
VB2= VC3=4.3 V
VI = VC3+VBE2=4.3+0.7 = 5 V????
I'm confused.. can you help me please? Sorry for my english
it's too difficult for me:

I do not understand elementary stages and how they work
Help me please
I think:
Q3 is a current generator (transistor connected diode like)
Q2 is a common base amplifier because the base is connected to ground for the signal
Q1 is a common base amplifier because the base is connected to ground. It takes the input signal from Q2 collector.
Q4+Q5 looks like a Sziklai Pair.
Is this correct? Maybe Q1+Q2+Q3 form a canonical amplifier + active load and I don't realize that!
How those stages work togheter?
The homework requires to find the continuous value of VI that corresponds to Vo=0.
But, supposing all transistor on active region:
VC3=-Vcc+VBE3=5-0.7=4.3 V
VB2= VC3=4.3 V
VI = VC3+VBE2=4.3+0.7 = 5 V????
I'm confused.. can you help me please? Sorry for my english
Last edited: