Texas Instruments Incorporated
Clockless decision feedback equalization (DFE) for multi-level signals

Abstract:

An apparatus includes a clockless decision feedback equalization (DFE) loop. The clockless DFE loop includes a summation circuit configured to combine a multi-level input signal and a multi-level feedback signal. The clockless DFE loop also includes a multi-bit quantizer configured to provide the multi-level feedback signal based on an output of the summation circuit. The clockless DFE loop also includes one or more analog delay circuits configured to delay the multi-level feedback signal to the summation circuit. The clockless DFE loop also includes a DFE tap circuit configured to apply signed DFE tap weights to the multi-level feedback signal.