Current controlling device and signal converting apparatus applying the current controlling device

摘要

A current controlling device (100) includes: a first resistive circuit (102) arranged to selectively conduct a first current (I1) to a first output terminal (No1) from a first input terminal (Ni1); and a second resistive circuit (104) arranged to selectively conduct a second current (12) to a second output terminal (No2) from the first input terminal (Ni1); wherein when the first resistive circuit (102) conducts the first current (I1) to the first output terminal (No1) and when the second resistive circuit (104) does not conduct the second current (I2) to the second output terminal (No2), the first input terminal (Ni1) has a first input impedance; when the first resistive circuit (102) does not conduct the first current (I1) to the first output terminal (No2) and when the second resistive circuit (104) conducts the second current (I2) to the second output terminal (No2), the first input terminal (Ni1) has a second input impedance substantially equal to the first input impedance.