Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [common-collector]

A common collector amplifier (also known as an emitter follower) is one of three basic single-stage bipolar junction transistor (BJT) amplifier topologies, typically used as a voltage buffer.

1
vote
1answer
77 views

BJT common collector amplifier with a voltage gain sligthly higher than one

How could I explain why a common collector amplifier has a voltage gain higher than one ? In a lab session, I built this circuit : With Vg=30 mVpp and Vcc=15V, students were asked to give the voltage ...
0
votes
1answer
50 views

BJT (Common-Collector Configuration)

As we know that for the transistor to operate in the active mode, it should have emitter-base junction as forward bias and collector base junction as reverse bias. So the common-collector ...
0
votes
1answer
58 views

Capacitor in common collector circuit

I have a question regarding \$C_1\$ capacitor - do we really need it in this circuit if we know, that the input signal will have no offset (i.e. \$\overline{V_{IN}}=0V\$)?
1
vote
3answers
205 views

Common collector transistor

According to my understanding the common collector transistor should be like figure-1 but in book it is given as figure-2 and in it Vcc is given.Can anyone provide me proper explanation of this.
0
votes
0answers
158 views

A good and valid example of Common Collector BJT

I am analyzing a common collector BJT as an amplifier using LTSpice. I have made the following circuit and I am not getting the exact characteristics which I should have got. Is there something wrong ...
1
vote
1answer
462 views

How to determine the input resistance of a bootstrapped emitter follower

I've used bootstrapping several times, either to boost the input impedance of an amplifier or to increase its gain. However most of the times I can see the beneficial effects of bootstrapping without ...
1
vote
2answers
128 views

Identifying the configuration of transisitors

I have been handed the diagram below, as part of an introduction to transistors. I am having a hard time finding out what type of configuration it is, therefore making it even harder for me to find ...
1
vote
2answers
718 views

Emitter follower/Common collector confusion

I'm in the need of a buffering circuit for a project and I would like to use a common collector amplifier or emitter follower for this purpose. Above is a schematics of the circuit I'm looking into. ...
2
votes
3answers
968 views

Understanding common terminal in common collector/emitter amplifier

I am beginner in electronics and trying to understand some basics. One thing that confuses me is transistor configuration with common terminals. Since transistor has three terminals then we must use ...
1
vote
2answers
915 views

Single supply op-amp voltage follower - negative clipping with AC-coupled load

I am using a µC running DDS algorithm to synthesize certain waveforms (in fact I made 3 channel music generator with portamento&ampltude modulation effects, commands for changing waveforms etc. ...
1
vote
1answer
191 views

All possible BJT circuits relating to polarity

The BJT can operate in 4 different modes/zones since there are two voltages on it: Active mode Inverse/Reverse active mode Saturation mode Cut-off mode Because Emitter and Collector junctions can ...
1
vote
1answer
245 views

Transfer function and frequency of Common-drain Colpitts with ballast coil

Whilst looking for a circuit to test some unidentified RF filters and coils I have lying about, I came across a FET based Common-drain Colpitts used in this youtube channel hosted by RF enthusiast ...
0
votes
2answers
724 views

Common Collector Biasing

The common terminal of the transistor configuration is also the GND of the circuit, right? I get it that emitter is GND but how is it possible for NPN transistor that base or collector is GND?
0
votes
2answers
130 views

Misunderstanding of amplifiying a current with transistor

Electrical books say that we can use transistor to amplifying current but when I simulate a circuit in proteus input current, it is smaller than emitter current but why? This is a common collector ...
0
votes
1answer
1k views

CC-CE multistage amplifier

I've an unsolved exercise to ask. The circuit is shown below: The first question ask to find a value of R2 for which Vout = 0 with Vin = 0. I think this question is referred to the small signal ...
0
votes
1answer
515 views

Common collector amplifier current amplification [duplicate]

given: Re = 500 Ω Rb = 261 kΩ What can we tell about the current amplification? Is this circuit useful?
0
votes
2answers
238 views

BJT Common Collector not swinging “negative”

I have an R2R DAC generating a 0-3.3V sine wave. This sine wave is fed into a non inverting op amp with a gain of 2. Then I'm trying to drive a 0.5W 50ohm speaker with a common collector amplifier. ...
0
votes
1answer
1k views

Cascading Common-Emitter Common-Collector for maximum power transfer

Hi Am trying to understand what am doing wrong, I connected CE to CC with a small Rload am designing it so Zout of the second stage equal Rload to get Maximum output. From what i read in CC-amp Zout =...
6
votes
2answers
3k views

How does this power supply circuit work?

This is the circuit of a power supply with adjustable output voltage and current, and I wish to understand how it works: What I did understand: R1 T1 VD5 - they form a voltage divider which provides ...