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Modeling >> Behavioral Models >> charge pump in veriloA
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Message started by Monia on Sep 29^th, 2005, 8:08am

Title: charge pump in veriloA
Post by Monia on Sep 29^th, 2005, 8:08am

I have some problems to model an output current in verilogA expecialy when I have to define an output voltage and a current value associated as in case of a charge pump.

Any suggestions

Monia

Title: Re: charge pump in verilogA
Post by Andrew Beckett on Sep 29^th, 2005, 10:16am

My suggestion would be that you give sufficient details for someone to have a clue what your problem might be!

Perhaps you could post your model, for example - even if it doesn't work. Together with a detailed description of what you want it to do.

Your question is so open ended, it would be impossible (I'd have thought) to answer it.

Regards,

Andrew.

Title: Re: charge pump in veriloA
Post by jbdavid on Oct 2^nd, 2005, 5:55pm

Monia.. most of us model the output of the chargepump as a current.. (possibly as a Voltage dependent Current) --
The VOLTAGE on the charge pump output is taken care of by the Loop filter input capacitance and the circuit simulator..
As with ALL circuit simulation tools, you can only specify one or the other.. Voltage or current..
If you want the output voltage to vary with Iout, then you include an output resistance in your model..
(Thevenin Eq. Model)
If you want the output current to vary with Vout, then you include an output resistance in parallel to the output current.. (Norton Eq. model.)
Hope this helps.
jbd