The present invention relates to a transconductance circuit intended to
convert a differential input voltage, supplied as two signals to two
inputs, IN+ and IN- respectively, into a differential output current.
According to the invention, each of the two signals of said differential
input voltage is supplied to each input, IN+ and IN- respectively,
through a follower transistor, TF+ and TF- respectively, connected to
said input, IN+ and IN- respectively, by its emitter and receiving said
signal on a control electrode. Moreover, each of the two inputs, IN+ and
IN- respectively, of the transconductance is connected to a respective
current source, CS- and CS+ respectively, that is dynamically controlled
by the other input of the transconductance, IN- and IN+ respectively,
said current source, CS- and CS+ respectively, being such that the
current supplies to each input, IN+ and IN- respectively, by said current
source, CS- and CS+ respectively, eliminates current variations caused by
voltage variations of the input voltage signal.