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Design >> Analog Design >> Impedance of a floating current source
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Message started by yvkrishna on Jan 21^st, 2010, 2:11am

Title: Impedance of a floating current source
Post by yvkrishna on Jan 21^st, 2010, 2:11am

I am working on classAB amplifier design which uses floating current source to bias the inverter(used as second stage)

I have read in couple of books saying that floating curr source will not present any impedance to the signal (proved mathematically also)
in the fig shown below it can be proved mathematically that vtest/itest =Rncas (approximately when gmp=gmn)

can some one explain how to understand/interpret this result?

also what is the impedance of floating curr. source at hi frequencies?

regards,
yvkrishna

Title: Re: Impedance of a floating current source
Post by yvkrishna on Mar 24^th, 2010, 10:57pm

any ideas for this ?

regards
yvkrishna