Patent ID: 6331787
Filing Date: 2001-12-18
Classification: H04L

Abstract:
An active termination circuit for terminating a signal traversing on a transmission line of an electronic device, comprising:a bottom clamping transistor coupled to a first potential having a bottom clamping transistor control node arranged for clamping said signal at about a first reference voltage;a bottom threshold reference transistor coupled to a first reference voltage supply configured to supply the first reference voltage, wherein the bottom threshold reference transistor provides a first bias voltage to said bottom clamping transistor control node that biases said bottom clamping transistor control node at about a first threshold voltage above said first reference voltage, said first threshold voltage representing a threshold voltage of said bottom clamping transistor;a top clamping transistor coupled to a second potential having a top clamping transistor control node arranged for clamping said signal at about a second reference voltage;a top threshold reference transistor coupled to a second reference voltage supply configured to supply the second reference voltage, wherein said top threshold reference transistor provides a second bias voltage to said top clamping transistor control node that biases said top clamping transistor control node at about a second threshold voltage below said second reference voltage, said second threshold voltage representing a top clamping transistor threshold voltage;a first stabilizing capacitor coupled between said bottom clamping transistor control node and a first stable voltage supply; anda second stabilizing capacitor coupled between said top clamping transistor control node and second stable voltage supply.