| 摘要 |
A gain control circuit includes first and second variable impedance devices connected between signal input and signal output terminals. A first current source (or sink) is connected to the connection point of the impedance devices and second and third current sinks (or sources) are connected to the input and output terminals. The output signal is controlled by varying the currents of the first through third current sources (or sinks) in such a way that the current value of the first current source (or sink) equals the total current value of the second and third current sinks (or sources). |
