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Simulators >> Circuit Simulators >> VCVS for differential signalling
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Message started by Larry_80 on Dec 6^th, 2011, 12:43pm

Title: VCVS for differential signalling
Post by Larry_80 on Dec 6^th, 2011, 12:43pm

Hello All,
In spice deck, one can measure the difference btw 2 node voltage by using E element with gain=1 i.e VCVS. I want to know how to measure the difference btw 2 curents I(Vx1)-I(Vx2). Can i use a CCCS in hspice for this?

Title: Re: VCVS for differential signalling
Post by loose-electron on Dec 6^th, 2011, 4:03pm

depends on the particular EDA tool and its capabilities.

If the direct method of current montior and buffer is not there, people build (sort of) equivalent models using small series resistances (milliohm in model is not going to affect most circuit designs) which produce a voltage equivalent to current signal, then add-subtract-multiply voltages, and then convert back to a current.

Depends on the tool set, most better ones have ways of monitoring the currents directly.

Title: Re: VCVS for differential signalling
Post by raja.cedt on Dec 7^th, 2011, 2:23am

hello,
so you want to measure current difference, so fist convert current into voltage and then subtract.

Thanks,
raj.

Title: Re: VCVS for differential signalling
Post by Geoffrey_Coram on Dec 15^th, 2011, 7:10am

Larry_80 wrote on Dec 6^th, 2011, 12:43pm:

I don't recall whether you can have two input sensors in the hspice CCCS; I would probably use a pair of CCVS to generate voltages from the currents, then use a VCVS to compute the difference in the node voltages.