All Questions

0
votes
2answers
58 views

differential amplifier gain

i know that the differential gain of the differential amplifier ( mosfet or bjt ) is _gmRc or _gm Rd looking at the curve : if the current went down in one side and up in one side the gm will change ...
0
votes
1answer
50 views

input resistance of differential amplifier

i have a question about the differential amplifier i know that the input resistance for the common mode is Rin = rpi + 2 Beta Ree / 2 but my question is what is the input resistance for the ...
0
votes
1answer
50 views

Gilbert Cell Output Current

I do not understand the basic of a Gilbert cell. I see that as its output we consider the output differential current Io. But I do not understand it. Is the load connected between the points 1 an 2? ...
1
vote
1answer
47 views

HFA3096 transistor array breakdown voltage

In the book Learning the Art of Electronics, one of the labs is to build a differential amplifier with a CA3096 transistor array. The author admits that the chip may be difficult to find and gives the ...
0
votes
0answers
54 views

Differential Amplifier Exam Problem

I am lost with how to approach part C and D of the question. In fact, I need some intuition with how to tune a differential amplifier.
0
votes
2answers
66 views

Finding Drain voltage of current mirror

Below I have a current mirror loaded differential amplifier. Can somebody please Just give me an idea of how to find the drain voltage, vd8. I am stuck because I don't see the relationships that can ...
-3
votes
1answer
67 views

Finding a range for a common mode signal

I have the question below Here is the figure they are talking about: (Text and images from: "Microelectronic Circuits" book by Sedra/Smith, 7th edition, chapter 9) Here are the answers to the ...
0
votes
4answers
387 views

How to apply 180 degrees out of phase signal at inputs of differential amplifier in laboratory when only one function generator is provided in lab?

In this differential operation experiment, two input AC signals have to be applied to the bases such that they are 180 degrees out of phase with each other, but I am not sure how to invert an AC ...
1
vote
1answer
643 views

Differential gain of amplifier with current mirror and NO LOAD

Please consider the differential amplifier (Q1&Q2) with current mirror active load (Q3&Q4) as shown below: simulate this circuit – Schematic created using CircuitLab I know many ...
0
votes
0answers
250 views

Choosing proper CCS current for discrete transistor amplifier's differential and VAS stages

Here is a figure from "Audio Power Amplifier Design" by Douglas Self. Self using almost same current values (4mA and 6-8mA) in many examples without explanation. How to choose these values properly ...
0
votes
3answers
2k views

Purpose of voltage amplifier (VAS) in three stage amplifier design

Can someone explain me benefits of this design (found in Douglas Self's book) in comparison with "classic" npn-based long-tailed pair? What second stage actually does?
1
vote
1answer
1k views

How to calculate the transconductance of this circuit?

I have this circuit where the "FES" blocks are simple current mirrors and the block "PD" is a differential pair. All the transistors in those blocks are BJT, NPN or PNP, respectively. I found all ...
1
vote
2answers
335 views

Saturation in differential pair

I'm reading Analysis and Design of Analog Integrated Circuits by Gray & Meyer. In the differential pairs' chapter, there is this circuit and it says: Assume the collector resistors are small ...
8
votes
1answer
1k views

How does this BJT transistor circuit works?

I just wanted to know a little more about this circuit about how it works a more in depth analysis I mean. I know there's some kind of differential amplifier and a Zener diode for voltage regulation ...
0
votes
2answers
163 views

differential amplifier will cancel DC present at input

In differential amplifier, it is written that "only AC signal will be amplified and DC part at the input will be canceled and hence there is no need of DC blocking capacitor". I am not getting this ...
1
vote
1answer
397 views

Modeling diode connected transistor in differential amplifier

I have question about the analysis of common-mode gain of BTJ differential amplifier with active load on the Sedra Smith book. In this book, the differential-mode gain \$Ad\$ is derived based on the ...
-1
votes
5answers
2k views

Use transistor to connect terminating resistor for differential signal?

Is it okay to use a transistor to connect a terminating resistor between the A and B lines of a differential signal? I'm not sure because I know that at the source/emitter of an NPN transistor must be ...
3
votes
1answer
2k views

BJT Differential Amplifier-Long Tailed Pair

I am trying to solve this assignment Consider this schematic (the BJT's are in the effective area, with \$\beta=200\$ so as to \$i_e\approx i_c\$). Also \$R_1>>R_E+r_e\$. Define the ...