Patent ID: 7539243

Claim:
A method of decision feedback equalization for digital transmission systems, using decisions on previously transmitted data symbols to suppress intersymbol interference (ISI) due to past data symbols, comprising: performing current-integrating decision feedback equalization at low-power, employing a fast capacitively coupled feed-forward path, including coupled switching capacitors, at the output of a current integrating buffer providing integration nodes, and inducing voltage changes by charge redistribution via the coupled switching capacitors; employing a digital-to-analog converter (DAC) via switches at coupling nodes to the coupled switching capacitors, for performing a voltage digital-to-analog conversion to determine a feedback coefficient as a coupling voltage; performing pre-charging of the coupled switching capacitors to a defined analog voltage value by resetting the switches to a pre-charge the coupling voltage to inject a defined charge on the integration nodes, and providing a well-controlled voltage drop at the integration nodes proportional to a feedback coefficient by grounding one of the coupling nodes via one of the switches in the buffers to eliminate thereby eliminating residual ISI caused by signal history, thereby and achieving current integrating buffering with switched-capacitor feedback during the integration and wherein said resetting involves triggering the capacitive switches by previous symbols.