Questions tagged [common-source]
A common source is one of the three basic FET topologies. It is distinguished by the fact that the input is at the FET's gate and the output is at the drain, leaving the FET's source as the "common" terminal. It typically exhibits high voltage gain but low bandwidth. Consider also using the "fet" or "mosfet" tag, as applicable.
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Output Noise of MOSFET with parallel current source
How can I calculate output noise voltage of the given circuit?
Noise contribution of the M1 to output noise current: $$4kT\delta g_{m1}$$
Noise contribution of the RG to output noise current: $$4kTR_G[...
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Analyzing \$g_m\$ vs \$V_{in}\$ for a common source config
I had this doubt while going through the book "Design of Analog CMOS Integrated Circuits" by B. Razavi, if we are to plot \$g_m\$ vs \$V_{in}\$ for the above circuit, then we have \$g_m\$ =0 ...
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For a MOS transistor, why is the maximum voltage of it be \$V_{dd}-V_{ov}\$?
Razavi stated that
the maximum output swing at X or Y is equal to \$V_{DD}−(V_{GS}−V_{TH})\$
as shown in the following picture, the second picture is the Fig.4.3
I don't understand why the equation ...
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What are the values for A1 and A2 in the output voltage?
I got this question wrong, but I am not sure why it is wrong. The only part of the question I got right was the time constant, which is 8 seconds. I have attached the question as an image. The ...
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For a degenerated CS amp with current mirror would the small signal model include the current mirror
I am aiming to create an actively loaded degenerated CS amplifier and analyse the small signal performance in relation to maximum signal levels, maximum signal swing, voltage headroom requirements, ...
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Floating node of amplifier in LTSpice
I have been trying to create an actively loaded degenerated CS amplifier with current mirror in LTSpice and whilst working on other aspects of the amplifier the Vout node decided it was floating. I'm ...
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Is it always given that ground has lower resistance than output even If output is far closer in an inverting nmos? [closed]
Currently I'm learning about MOSFETs (N-MOS and P-MOS) --basically how a transistor works. My question is why does the current always prefer the grounding output even though it is further away than ...
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Output level of common-source amplifier with PMOS load
Let's consider the common-source amplifier circuit above (left). This circuit does
not have a well-defined output level. This part is easy to understand. In the
book by Razavi, he says this "...
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Why does the PMOS default straight to Triode in this common source amplifier? and how can I mathematically show it?
start by assuming both transistors are saturated. even though the title says otherwise
I want to find the operating point of this circuit with these parameters.
Vbiasn = 2V (relative to GND)
Vbiasp =...
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MOSFETs as amplifier
I have used bipolar transistors as amplifiers but am having confusion regarding using MOSFETs as amplifiers. In the bipolar transistor case I use the simple formula of R2/R1 where R2 is the collector ...
user340506
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What purpose do these capacitors have? [closed]
What is the purpose of Cc1,Cc2 and Cs and what is the normal range of these capacitors? Also what is Negative Feed Back(Rs) mean I can't understand it.
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CS amplifier feedback stability
I playing with JFET Common Source amplifier with feedback loop. I am simulating the design showed here. https://www.ti.com/lit/an/slpa018/slpa018.pdf?ts=1669662908797&ref_url=https%253A%252F%...
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How to bias a common-source amplifier with a current-source load in moderate inversion?
I am using the gmid method to design a common-source amplifier. The gmid method forgoes the use of the square-law equations for lookup-tables/charts to provide accurate results when designing circuits....
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Obtaining the expression of the noise figure for this common source
I'm trying to obtain the expression of the noise figure defined for this circuit :
The transistor is in saturation, and strong inversion. The flicker noise can be ignored.
Here is my attempt:
For ...
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Biasing for complementary common-source stage amplifier
Why does no current flow through \$R_F\$ in the absence of signals in Fig 5.47(b)?
This can only happen if \$V_x = V_\text{out}\$. How is that guaranteed??
