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Hi,
I didn't understood what you meant with removing the current source. JoannesPaulus is of course right.
If the variation over PVT is a critical point in your design, I suggest you to bias your comparator with a PTAT current source to reduce the drift over Temperature.
You have to be careful, increasing the size of the input pairs will increase the capacitance and then increase the kickback and can reduce the speed.
Concerning the current source, if you remove it, it should not work !!
The current source is needed to bias the differential pair.
But if you increase the lenght of the cascode, you will then decrease the gm and decrease by the same way the output resistance.
Or you mean, keeping the same W/L ratio and increasing L ?
Your oscillator could not be temperature independent. The frequency is clearly dependent on the Vth of your MOS. The Vth will drift with temperature.
The only solution I know is using some voltage and/or current reference. But of course, that will increase your current consumption.
Hi,
I've always used for my cascode a short L (0.5 µm), then increasing the gm.
I've heard that some peolple are using a long L for the cascode. I don't understand why, and I don't understand how it should works.
Have you some explanations for that ?
Thanks in advance
relaxation oscillator for low frequency
Hi,
can you please give us some specifications for your oscillator. I would guess that it is a low frequency oscillator (some MHz).
Does your oscillator be temperature independant ?
Hi,
the MC parameters given with your models are normally measured with good layout techniques. (for example, to measure the deviation of a Vth, an array of transistor is done (all transistor are well matched in layout) and the Vth is measured for each transistor).
So if you simulate the...
sandworks waveview
Hi,
The size of my files is between 5GB to 40GB. I don't have more than 20-30 wave in my database.
I always open the database when my simulation is finished.
The version I used is quite old : AMS2004.3.
Some few bugs I met :
- ezwave crash quite often
- the waves are...
rfsystem,
I agree with your first sentence
But I don't understand the last one.
I never run monte-carlo simulation at corners because this is not realistic at all. Can you please explain in a better way if I'm wrong ?
Thanks
ezwave
Hello,
I actually use EZWave to view the waves results of my simulation (with eldo). But I don't like this viewer : it doesn't support very big file, there are a lot of bugs and the script possibilities are too low (or bad documented).
I heard some positive feddback concerning Waveview...
Hello,
I have written some Tcl scripts and use them in eldo to define new waves. I'm now facing with precision problems.
Eldo send data in engineering notation with only 6 digits (ex: 9.123456e-6) and that's not enoughfor my purpose.
I have already try to change the NUMDGT option without any...
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