US 5,329,190 AGranted

Termination circuit

AssigneeInternational Business Machines Corporation

InventorsRyo Igarashi, Tatsuo Morikawa

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Abstract

A termination circuit having a large margin which prevents the occurrence of a reflected wave due to a noise at the far end of a transmission line, thereby reducing the power consumption in the termination impedance. The termination circuit is constructed such that a first transistor is connected to a first potential and a second transistor is connected to a second potential which constitute the output stage of the termination circuit. The transistors are driven by first and second inverters having different input/output characteristics, respectively, thereby increasing the operation margin of the termination circuit. Particularly, if the second potential is assumed to be lower than the first potential, the second inverter driving the second transistor has such input/output characteristics that it outputs an output voltage which turns off the second transistor before the first inverter turns on the first transistor as the input voltage increases.

Claims12

Dependent claims

A termination circuit comprising:

an output stage having an output node connected to a far end of a transmission line for terminating the far end of said transmission line with an impedance substantially equal to the characteristic impedance of said transmission line, said output stage having a first transistor connected to a first potential and a second transistor connected to a second potential, each of said first and second transistors having a control electrode,
a first inverter connected between the far end of said transmission line and the control electrode of said first transistor for driving said first transistor in response to a signal at the far end of said transmission line, and
a second inverter connected between the far end of said transmission line and the control electrode of said second transistor for driving said second transistor in response to the signal at the far end of said transmission line, said second inverter having input/output characteristics different from the input/output characteristics of said first inverter.

Dependencies are inferred from the claim text.