ideal switch in Cadence

[hebu]

cadence switch

We can find a "switch" in analogLib of cadence, but I don't know why
it can't function as my expectation. So, anybody know do cadence provide
"ideal switch" for simulation purpose?

Thanks,

 

[kienhuy]

cadence ideal switch

I think I've used that switch before without any problems. What did you specify for the open and close resistances and open and close voltages?

 

[hebu]

spectre ideal switch

I don't really know the purpose of open voltage and closed voltage. And
what the purpose of the four terminals. I would like to use it as a mos switch.
I have tried it several times but I still don't know how to use it.
Could you give me any guidance?
thanks,

Added after 8 minutes:

I attach the schematic I used.

 

[uncle_urfi]

ideal switch in spectre

You can use a pMOS and an nMOS transistor (minimum size) in parallel as a transmission gate switch. You can read about it on the internet. just Google.

There will be charge-sharing problems, the solutions to which can also be found in text-books.

I remember helping someone on the same topic; You can also use a voltage variable resistor with very high resistance for the off-case and very low resistance (on-case).

The above schematic is quite clear as well. There are two control pins and two circuit pins.

 

[hebu]

switch in cadence

Thanks for your help, but do you know waht's the function of switch
provided by candence. I really don't know how to use it. it's not straightfoward.

 

[Hughes]

analoglib switch

Which simulator did you choose to simulate the switch? The ideal switch is applicable for spectre but not for hspiceS.

 

[hebu]

cadence switch open voltage

My simulator is spectre.
May I use it? or I should change it to SpectreS or other?

 

[nxing]

ideal switch cadence

Hi,

I have experienced the same problem. However, when you give the initial state of the net connected your switch, it will works fine.

 

[kienhuy]

cadence help on ideal switch

The two terminals on the coil side are the controlling terminals. The other two are for the switch.The open voltage and close voltages specify the thresholds for which the switch is open or closed. For example, if your open voltage is 2V and close voltage is 4V, then the switch will be open when the there is less than 2V across the controlling terminals and closed when there is more than 4V across the terminals. The open and closed resistances specify the resistance of the switch when it is opened and closed, respectively.

 

[Irfansw07]

HI

I am new to this use of ideal switch...
Can anyone please help me in telling that if I can use this switch instead of transistor in Inverter...
I want to check how it works so I want to start with use as switch instead of transistor in Inverter test bench circuit..

Thanks in advance

 

[awatifamir]

Hi, may i know how can I design this type of switch in the layout. I have no idea since there were no layout for this type of switch. I plan to use Virtuoso for layout.

 

[pavel_adameyko]

how can I design this type of switch in the layout. I have no idea since there were no layout for this type of switch. I plan to use Virtuoso for layout.

There is ideal componet, you can't use it in real. So there is no layout for it. You can use it only in schematic to model real switch consisting of real transistors, whose layout you can draw.

Can anyone please help me in telling that if I can use this switch instead of transistor in Inverter...

You can model this component to replace transistors operating in switching mode, as an example the inverter on picture below - it works.

 

[datone520]

hi ,all
first, thanks for sharing your experience .can anyone tell me what's difference between seting open switch resistance ,close switch resistance and open voltage,closed voltage?
thanks and reguard

 

[pavel_adameyko]

hi ,all
first, thanks for sharing your experience .can anyone tell me what's difference between seting open switch resistance ,close switch resistance and open voltage,closed voltage?
thanks and reguard

Hi
Open switch resistance = 1M
Close switch resistance = 100
Resistance = 1K
Open voltage = 0
Close voltage = 3
So the switch resistance vs. governed voltage would be

Regards.

 

[mvj]

Hi All,

The parameter "close voltage" does not seem to be working. I have used the switch with the following parameters:
open voltage = 2V
close voltage = 10V

From my simulation I see that the switch closes when control voltage is above 2V and opens when the control voltage is below 2V. The close voltage 10V does not seem to have any importance. Is it not?

May I know if this can be expected?

Thanks a lot in advance!!
M

 

[JoannesPaulus]

I think it works fine. Try a current source directly into the switch: when the switch is closed the "close switch resistance" is used, when its open the "open switch resistance" and when it is in between (i.e. between 2V and 10V) the "resistance" is used.

 

[fanofai]

When simulating, I noticed that the polarity of the switch is important. The coil has two terminals NC+ and NC-. Make sure that NC+ is greater than NC- for the switch to be on. I just spent hours on debugging because I had flipped the terminals!