All Questions
21
questions
0
votes
2
answers
155
views
Vout NMOS CS amplifier LTspice simulation
I've been trying to create this 2 block cs amplifier for a 5V/V gain. The problem is that my Vout is saturated on both cycles, and I do not know why this is happening.
The transistor used is NMOS ...
- 1
1
vote
2
answers
676
views
How is common source NMOS stage with active current load realized in practice?
In a well known book about CMOS circuit design (Design of Analog CMOS Integrated Circuits) I found this example about a cascode stage with current source load.
The basic idea is, to replace the drain ...
- 440
3
votes
2
answers
1k
views
Intrinsic gain of NMOS
In Razabi's Design of Analog CMOS Integrated Circuits textbook, the example 3.2 asks for the small signal voltage gain of the circuit below:
He explains that since the current source I1 introduces an ...
- 447
0
votes
0
answers
421
views
Proving that we can apply the half-circuit model for the common-source differential amplifier
This is the circuit I'm trying to solve through the half-circuit model:
To do so I need to first prove that \$V_{p}\$ is a small-signal ground under opposite symmetric excitation (\$v_{in1}=-v_{in2}\$...
- 337
3
votes
3
answers
448
views
What type of amplifier is this?
I have a question about the amplifier with circuit shown below:
I don't understand if this is a voltage or a transimpedance amplifier.
Can someone provide some explanation?
- 31
0
votes
3
answers
1k
views
Understanding common-source amplifiers with resistive degeneration
I understand that by introducing the series resistance to the NMOS in the amplifier circuit the gain becomes:
$$A_{v}=-\frac{R_D}{\left(\frac{1}{g_m}+R_s\right)}$$
Which means that higher values of \$...
- 337
0
votes
1
answer
111
views
Sharp transistor cut off outside active region
I'm building a simple temperature controlled NMOS switch for regulating the speed of a fan.
It's a 12V fan and the controller works great (as long as the transistor is in it's active region.)
This is ...
0
votes
0
answers
133
views
Is it possible to implement a high-side current mirror with only NMOS FETs?
I need to implement a difference amplifier only using NMOS technology. I am struggling when trying to reference the voltage difference to ground. From my reading it looks like I need a high-side ...
- 791
0
votes
1
answer
132
views
Am I applying the KCL the right way? [closed]
Applying KCL at the node where I have drawn the currents in order to find Vin/Vs,
I am not getting the correct answer which however I did obtain using the Voltage Divider. My question is, am I using ...
- 149
0
votes
2
answers
147
views
My transistor used in a transistor amplifier does not get turned off with PWM based input
I am working on a project; driving a DC MOTOR using an NMOS MOSFET amplifier and Arduino PWM signal.
My problem is my transistor amplfiler is always on when I vary the PWM input value from 0 to 255. ...
- 11
1
vote
0
answers
247
views
Maximum mid-band gain of s.s. model MOSFET amplifier?
Schematics
I need to find the maximum possible gain for this NMOS cascode circuit.
Here is the s.s. model:
Work
I used nodal-matrix analysis (basis is KCL) to find the gain (\$A_v\$):
$$
\...
- 177
0
votes
2
answers
98
views
How to amplify the output of an on NMOS, connected to zero source voltage?
I am simulating a 3 transistor based XNOR cell using HSPICE. The circuit is shown in the picture.
technology = 45nm
Vdd=1.1v
|Vth|=0.62v
In the case of A=1 and B=1, the output is charged through ...
2
votes
1
answer
400
views
Current amplifier with Mosfet and Op-Amp: Output resistance
In the following circuit, why is \$R_o\$ given by:
\$R_o=(R_1//R_2)+r_{o2}+g_m .r_{o2}.(R_1//R_2)\$ ?
I dont understand the \$g_m .r_{o2}.(R_1//R_2)\$ parcel
- 177
0
votes
1
answer
3k
views
MOS Amplifier Circuits with Feedback
The following images show NMOS amplifiers circuits with feedback:
a)Transconductance (tension source, current output (RL)) -> current sampling, tension mixing
b)Transresistance (current source, ...
- 177
0
votes
2
answers
141
views
NMOS Inductor Circuit
I could not understand the logic of this circuit, connecting an inductor to the supply what will change? Considering that C1 acts like a short circuit in AC analysis why do we differentiate x and Vout ...
- 39