Equalizer

An equalizer circuit of signals transmitted on a line having an attenuation comprising:

• an analogical adaptive filter coupled in series with said line and including plural transconductance filters each having a respective bias current, a pole, and a zero, the pole and zero each having a respective position in frequency in a working band that is variable in response to said respective bias current;
• and
• a retroaction circuit coupled to an output of said adaptive filter and able to vary said respective bias currents, each bias current varying at a varying of said attenuation of said line;
• wherein each bias current of said plural transconductance filters has a prefixed value and is made to vary at an increase of said attenuation so that said pole of the bias current is moved toward high frequencies of said said zero is moved toward low frequencies.

An equalizer for signals transmitted on a line having an attenuation, the equalizer comprising:

• an adaptive filter including:
• an input coupled to an input portion of the line;
• an output coupled to an output portion of the line;
• a first transconductance filter having a bias input at which a first bias current is produced;
• and
• a second transconductance filter having a bias input at which a second bias current is produced;
• a line attenuation detector coupled to the output of the adaptive filter and structure to detect attenuation in the line;
• and
• a variable bias generator having an input coupled to the line attenuation detector, a first output coupled to the bias input of the first transconductance filter, and a second output coupled to the bias input of the second transconductance filter, the variable bias generator being structured to vary the first and second bias currents in response to receiving an indication from the line attenuation detector that the attenuation has changed.