| 摘要 |
<p>A negative feedback circuit includes: a voltage follower for following a reference voltage; a proportional current mirror whose proportion of inputting current and outputting current is a: b ; a compare judging device, comparing the voltage across the reference resistance with the voltage across a first variable resistor, getting a regulating signal and inputting the signal into the third regulating port of the first variable resistor, then inputting the signal into the third regulating port of a second variable resistor via a hold unit, in order to regulate the resistance of the first and the second variable resistor synchronously, make the resistance of the first and the second variable resistor equal to the terminate resistance value needed .A method and an apparatus of on-chip transmission line impedance match are provided. The negative feedback circuit, the method and the apparatus of the present invention may implement the impedance match of the different impedance transmission line without changing the external circuit. Comparing with the conventional scheme, the cost is lower , the use is more convenience and flexible.</p> |
