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1  Other CAD Tools / Entry Tools / Export effective cds.lib contents
 on: Today at 9:28am 
Started by pupule | Post by pupule
Hello,

I have a cds.lib that is created by a few files with a number of environment variables set by project setup files.  Is there a way to export an effective cds.lib file with all of the environment variables elaborated?

Thanks,
Pupule

2  Design Languages / Verilog-AMS / hAMSter Model Editor Error Messages
 on: Today at 9:18am 
Started by loumbut5 | Post by loumbut5
Hi, sorry for the ambiguous topic but I have just started coding VHDL-AMS today. Smiley
Anyways, I am encountering the following errors while compiling and simulating my code which I am manually translating from SPICE to link with VHDL. Cool

Error : Cannot save/load file "C:\Program Files\Hamster\Lib\\ieee\electrical_systems_pack\electrical_systems.package_bin"
Error : Library "spice2vhd" not found

The first error is beyond me. I don't know what the compiler wants. My directory only goes to C:\Program Files\Hamster\LIB\ieee\ with no electrical_systems_pack directory in the installation.
The second one is confusing since in the LIB directory, I have added the SPICE2VHD file attached.
Though I am not sure if I have saved it correctly since it is two packages in one. Roll Eyes
If you happen to know how to assist, please do. Smiley

3  Simulators / Circuit Simulators / Re: DC Resistance vs ron in Nmos
 on: Yesterday at 6:04pm 
Started by kabir_fakir | Post by Ken Kundert
Replace the resistor between the source and ground with a voltage source. You can sweep the DC voltage of this source to get an idea of how the resistance of the switch changes with bias.

Replace the voltage source that connects between the drain and ground with a voltage source that connects between the drain and the source. This source would be 0V DC and 1V AC. The switch's on conductance is then equal to the AC current through this second source.

The AC analysis would be configured to sweep the DC voltage on the first source while setting the AC frequency to a constant 0 Hz.

-Ken

4  Simulators / Circuit Simulators / Re: DC Resistance vs ron in Nmos
 on: Yesterday at 11:47am 
Started by kabir_fakir | Post by DanielLam
I don't think that's the s2pswitch. I think it's just a schematic symbol they made.

That sim has 3 parallel resistance measurements, you only need one.

5  Simulators / Circuit Simulators / Re: DC Resistance vs ron in Nmos
 on: Yesterday at 1:46am 
Started by kabir_fakir | Post by kabir_fakir
DanielLam wrote on Jul 19th, 2017, 4:26pm:
I'm copying and pasting a post I made about the Ron testbench.
( http://www.designers-guide.org/Forum/YaBB.pl?num=1443544276 )

The oregon page has the setup for Ron. I've used it hundreds of times. Look for on-resistance of a switch. You can do a parametric sweep of W/L versus Vcm.

If you get an impedance, take the real part of it to get resistance.

http://web.engr.oregonstate.edu/~moon/kaj/cadence.html


Thanks for the reply. Interestingly I have already found this test bench but I did nt get the purpose of switch( I think its sp2switch) in the test bench.

6  Design / RF Design / Re: 50 Ohm match in IC?
 on: Yesterday at 1:22am 
Started by RC | Post by tzg6sa
If stand-alone then you will have no interstage matching on your die. You will interface it with the off-chip world. In this case if you do not know what impedance to use, just stick with 50ohm.

7  Simulators / Circuit Simulators / Re: DC Resistance vs ron in Nmos
 on: Jul 19th, 2017, 4:26pm 
Started by kabir_fakir | Post by DanielLam
I'm copying and pasting a post I made about the Ron testbench.
( http://www.designers-guide.org/Forum/YaBB.pl?num=1443544276 )

The oregon page has the setup for Ron. I've used it hundreds of times. Look for on-resistance of a switch. You can do a parametric sweep of W/L versus Vcm.

If you get an impedance, take the real part of it to get resistance.

http://web.engr.oregonstate.edu/~moon/kaj/cadence.html

8  Simulators / Circuit Simulators / Re: DC Resistance vs ron in Nmos
 on: Jul 19th, 2017, 12:33pm 
Started by kabir_fakir | Post by Maks
The switch has two states - on and off.
In off state, it will see the full voltage VDD, but Vgs is zero and its the switch resistance is huge.
In on state, Vgs is maximum, and Vds will be (should be) small, otherwise you will burn out your transistor. In on state, its resistance Rdson is small.


9  Simulators / Circuit Simulators / Re: DC Resistance vs ron in Nmos
 on: Jul 19th, 2017, 11:07am 
Started by kabir_fakir | Post by kabir_fakir
Maks wrote on Jul 19th, 2017, 10:58am:
Just replace 1GOhm resistor with 1 mOhm resistor, to improve your accuracy (as Ken suggested), us max (nominal) Vgs, and small value (like 0.1 V) for Vds.


but am i not suppose to sweep the vds for larger range , because in my design drain terminal is changing from 0 volt to 9 volt. So I dnt understand why small value of vds?

In fact, I am asked to measure both ac resistance (small signal i.e ron) and also  the slope of the line connecting (0,0) with (Vds,Ids) (I call it large resistance)

10  Simulators / Circuit Simulators / Re: DC Resistance vs ron in Nmos
 on: Jul 19th, 2017, 10:58am 
Started by kabir_fakir | Post by Maks
Just replace 1GOhm resistor with 1 mOhm resistor, to improve your accuracy (as Ken suggested), us max (nominal) Vgs, and small value (like 0.1 V) for Vds.

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