Re(2): 2nd generation VCFs (was: Xpander VCF)

[tomg]

See....EXPERIMENT#5: BJT CURRENT MIRRORS
V. CIRCUIT 3: Wilson Current Mirror 
http://www.cse.ucsc.edu/classes/cmpe171/Fall99/labs/lab5.html

Tom

> 
> 
> > >The patent
> > >calls for n,p,n,p current mirrors. n,n,n,n also works but has about
> > >1/2 the gain. 
> > 
> > How could that be ? Current mirror means reverting the direction, so
> > how could it possibly work with npn only ??
> 
> 
> 
>