All Questions
15
questions
6
votes
2
answers
749
views
How to decide sizes for transistors in a design? What does it mean to design an IC?
I have recently started designing analog ICs as part of my academic work. So far all I do is take topologies given in textbooks or papers and try to design them in the PDKs available at my university. ...
- 505
0
votes
0
answers
23
views
Clock feedthrough of the bootstrapped switch
I'm learning about the bootstrapped switch through this paper. Razavi used a 20 µm / 28 nm NMOS (M1) as the main switch to achieve low Ron. I am wondering does this wide device cause any problem ...
- 625
0
votes
1
answer
43
views
How does analog IC benefit from channel length shrinking?
I have some experience in OTA design for both 180 nm and 130 nm technologies. I didn't see much advantage of using 130 nm, as I had to use quite long channel length to achieve an acceptable gain in ...
- 625
15
votes
1
answer
2k
views
What is the standard procedure for analogue IC tapeout?
This is probably a very broad question and I will try to be more specific. I'm asking this question to get a sense of the gap between my knowledge and a 'successful' tapeout, as I've heard many people ...
- 625
2
votes
0
answers
124
views
RHP pole of two stage OTA
I learnt that for any amplifier (with some capacitor) if we short/open the capacitor and the polarity of gain changes, it is a sign of RHP zero.
Now, while applying the same analysis I obsevred that ...
- 209
6
votes
4
answers
2k
views
Slew rate of two stage OTA
I have learnt two stage opamp designing from books and yourtube videos, but have always failed to understand slew rate formula which is I5/Cc(I5 is bias current of M5 and Cc is compensation capacitor)....
- 209
0
votes
5
answers
231
views
Ohm's law Vs. Ohm's relation (which one is right)?
Ok, so this might be a stupid question but I just had to ask.
We are all taught that Ohm's law is:
V = IR
I have heard some people that insist that it should be called Ohm's relation instead of ...
- 399
2
votes
1
answer
462
views
How is a PMOS transistor used as a switch?
I am trying to understand switching behaviour of PMOS transistor and how exactly it passes a bad 0 value. I'm getting confused with the notation.
More specifically, ...
- 157
1
vote
2
answers
1k
views
Zero in a basic RC high pass filter
If I write the transfer function I can clearly see a zero at zero frequency and a pole at 1/2πRC frequency. But If I simply look at this circuit I would say that there is one pole and no zero(as there ...
- 209
0
votes
0
answers
190
views
CMOS vs BiCMOS technology nodes comparison
I am trying to make a comparison between several technology nodes. More specifically I want to compare 28nm, 40nm, 65nm CMOS and BiCMOS processes. However I cannot find papers that compare some of ...
- 57
2
votes
2
answers
876
views
Parasitic insensitive switched capacitor circuit
I'm trying to simulate the parasitic insensitive switched capacitor circuit shown here:
I am using cadence virtuoso. My input is a sine wave of 1 V amplitude, 0 DC and 1 kHz frequency. I am using ...
0
votes
1
answer
197
views
Selecting Time period with multiplexer
Varying input signal I want to select delay line based on the time period of input and tap out the output of delay line to input to Multiplexer.
For Example: Input Time period 1ns the input to Mux ...
1
vote
1
answer
573
views
What determines the discharge time of Dual slope ADC?
I were watching a video about dual slope ADC's here on youtube
simulate this circuit – Schematic created using CircuitLab
I understand that the charging equation is $$ \frac{{V_{in}}\times{t_1}...
- 1,313
0
votes
1
answer
995
views
Power down current
I'm designing a Variable Gain Amplifier (VGA) for a course project. I'm using Cadence CMOS 180nm technology. One of the requirements is to find the power down current through simulation. I searched on ...
- 21
2
votes
1
answer
600
views
Free spice Model to simulate integrated circuits design
I am using ltspice and I would like to simulate integrated full custom circuits for educational purpose.
I found the NMOS4 and PMOS4 models but there are not enough since there are too ideal there ...
- 455