摘要 |
A resistor mirror which biases transistors substantially in their linear region of operation and in such a way that their combined parallel resistance is equal to the resistance of a reference resistor. The resistor mirror may include three or more offset control circuits, a feedback control circuit with a reference resistor, a reference voltage-controlled resistor, and one or more additional voltage-controlled resistors. The offset control circuit includes two voltage-controlled current sources. Three or more offset control circuits are connected in a manner so as to affect an equal number of resistor control output terminals coupled to the reference voltage-controlled resistor and to the additional voltage-controlled resistors. To minimize signal coupling between multiple voltage-controlled resistors coupled to the same resistor control output terminals, and to insure stability in the circuit's operating point, a filter capacitor is coupled to each resistor control output terminal. Additionally, through transistor scaling, the resistance of any voltage-controlled resistor may be a multiple or fraction of the reference resistor.
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