摘要 |
A differential termination resistor adjusting circuit includes: a reference current producing section that produces a nearly constant reference current Iref, a reference voltage producing section that produces nearly constant reference voltages VrefH, VrefL, a replica resistor producing section that is provided with the reference current Iref to produce voltage drops Va, Vb, a control voltage producing section that produces control voltages Vcont1, Vcont2, based on the reference voltages VrefH, VrefL and the voltage drops Va, Vb, and a genuine resistor producing section that is built in a receiving side device and is connected to an input termination, characterized in that the resistances of the replica resistor producing section and the genuine resistor producing section are adjusted by the control voltages Vcont1, Vcont2.
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