摘要 |
A negative feedback circuit including: a voltage follower for making the output voltage follow a reference voltage, a proportional current mirror for outputting a current in proportion to a reference current via a reference resistor as a input current of the proportional current mirror, a comparison arbiter for comparing the voltage across the reference resistor and the voltage across a first variable resistor to acquire a regulating signal, inputting the regulating signal to the third regulating end of the first variable resistor and inputting the regulating signal to the third regulating end of a second variable resistor to synchronously regulate the resistances of the first and second variable resistors and thus make the resistances of the first and second variable resistors equal to the desired terminating resistance. The present invention also discloses a method and apparatus for performing on-chip impedance matching for a transmission line.
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