Abstract: Systems and methods are described for adaptive equalizers. A circuit adapted to transform an equalizer input signal at a receiver to approximate an output signal at a transmitter includes an equalizer, a phase matching loop coupled to the equalizer, and an amplitude locking loop coupled to the equalizer. The equalizer can include a number of coarse band segments to provide coarse adjustment, at least one of which includes a number of fine band segments to provide fine adjustment. The systems and methods provide advantages in that multiple cable lengths can be serviced by a single equalizer, variations in the low frequency gain and the location of the zero point due to variations in manufacture and operating temperature are obviated, and a suitable gain can be provided at much higher frequencies.

Abstract: Systems and methods are described for implementing a backplane in the context of a stack of networking hubs based on a backplane connecter and for carrying out a method of configuring and terminating the backplane. A backplane connector includes a first voltage source; a plurality of connector contacts; a plurality of termination resistors, a first end of the plurality of termination resistors being coupled to the plurality of connector contacts; a first switch located between the first voltage source and a second end of the plurality of termination resistors; a first logic circuit coupled to the first switch, the first logic circuit closing the first switch when a layer composed by the backplane connector is both i) active and ii) either a top layer in a stack composed by the layer or a bottom layer in the stack.