Stats

  • Locked Locked
  • Replies 8
  • Subscribers 125
  • Views 16582
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Charge Pump output Capacitance

Mushir

Hi 

 I am using a capacitive load in charge pump in CADENCE h035 technology. But when I am creating charge pump symbol and using it in other circuit   its showing errors while simulating (runs upto 1% and the spectre error) I know its due to the load at the output port of Charge pump but I dont know how to use it or replace it because that output capacitance is very important.

 Please suggest me something.

 Thanks in advance.

 

Mushir 

  • Mushir,

    I would respectfully ask you to read the forum guidelines. A few points:

    1. There is no such thing as "CADENCE h035" technology. Cadence provides the EDA tools, but does not provide manufacturing technology - so you're presumably talking about a Process Design Kit from some foundry or other - knowing which one would likely help anyone answering your question.
    2. You didn't say what the actual problem or error was
    3. You didn't say what tool versions you're using
    4. Showing your circuit would most likely help.

    But this kind of thing is all in the guidelines.

    Kindest Regards,

    Andrew.

  • Hi Andrew

    Yeah I did a mistake while writing the technology and tools. I am using AMSh0.35um technology and Virtuosos 6.1.5 tool.  The actual problem is that when I am using the Symbol of this charge pump circuit with the output capacitor load and then integrating it with other circuit(basically a switch in this case) there is Spectre error coming. If I am using it without the load capacitance then its working fine. But I need the load capacitance in the charge pump.

    I have attached the circuit below.

    Thanks

    Mushir

  • Hi Mushir,

    No circuit was attached, and you didn't show the error...

    Kind Regards,

    Andrew.

  • Hi Andrew

     

    I pasted the circuit schematic but I dont have any idea why its not showing in the post. It went through some moderation also before getting posted. I am new to this forum so I am not sure what is the problem with it.

     

    Thanks

    Mushir 

  • Mushir,

    Use the Options tab at the top of the page to attach a picture (e.g. a png file) rather than trying to paste in an image.

    Regards,

    Andrew.

  • Hi Andrew

     I have attached the screenshot of the circuit scematic and error screen.

     

    Regards

    Mushir

  •  Hi Andrew

     This is the error screen

     Thanks

    Mushir

  • It's still not really enough to go on. Presumably the convergence difficulty is caused by some numerical instability in the circuit - and without seeing the data, it's going to be very hard to debug (you didn't mention which device makes the difference). Usually small timesteps are caused by discontinuities in the device models, combined with large component values (or negative component values). I see you have a 500pF cap there, which is large (for IC) but not immense. There appear to be some 50uF capacitors too - but maybe that's just the resolution of the image - driving these with a 10u/0.5u transistor seems a bit hopeful.

    Maybe you should contact customer support? Then we can properly look at your data, maybe.

    Regards,

    Andrew.

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.