Circuit for matching data bus controller to symmetrical bus line - has filters for attenuating HF components, and evaluation delay which is set longer than filter delay

摘要

The bus controller is matched to a symmetrical bus line, pref. in a CAN bus system. Filters (F1,2) are incorporated into connecting lines between the controllers and the bus lines, for attenuating HF signal components. The controller contains an adjustable evaluating delay, greater than the sum of the signal transit times in the incorporated filters. The filters in the transmit and reception branches are symmetrically designed. In the bus line, the filters are deccoupled by adaptive amplifiers, with the filters having approximately a Gaussian filter characteristic. A low transverse capacity reactance may be fitted in the tranmit signal path from controller to bus line. USE/ADVANTAGE - For physical layer adaptive hardware in vehicle, without subjecting car aerial to high frequency interference.