In the paper 'A Wideband CMOS Variable Gain Amplifier With an Exponential Gain Control',a Voltage-to-Current Converter is realized and the structure is shown in the following figure。1 S6 o1 @- Z9 |# _6 B- W& R
/ p: w0 R/ n3 kIn the figure,VC** denotes the voltage copier and current generation,Here ,i don't understand why VC** can copy voltage from node A to node B。" O% G* Z) r* }9 Z5 n! i0 ]