Patent ID: 6326817
Filing Date: 2001-12-04
Classification: H03F,H04L

Abstract:
A circuit for suppressing a common mode component in a signal from a communication bus, comprising:a first supply terminal (28) and a second supply terminal (32) for the connection of supply voltages,a first bus terminal (2) and a second bus terminal (4) for the connection of respective wires (CANH, CANL) of the communication bus,a voltage divider (6, 8, 10, 12) connected between the first bus terminal (2) and the second bus terminal (4),a differential amplifier (20) having inputs (22, 24) connected to taps (14, 18) of the voltage divider,a first current conducting element (26) for coupling a center tap (16) of the voltage divider to the first supply terminal (28), anda second current conducting element (30) for coupling the center tap (16) of the voltage divider to the second supply terminal (32), characterized in thatthe first current conducting element (26) comprises a first pair of transistors (M1, M2) of a first conductivity type arranged in parallel and having their control electrodes connected to further taps (34, 36) of the voltage divider, andthe second current conducting element (30) comprises a second pair of transistors (M2, M4) of a second conductivity type arranged in parallel and having their control electrodes connected to the further taps (34, 36) of the voltage divider.