| 摘要 |
A control circuit for controlling a level of an audio signal and transmitting the signal to an amplifier is described. The control circuit is based on an R-2R resistor network having a first plurality of resistor nodes and a parallel resistor network having a second plurality of resistor nodes. Each of the resistors in the parallel network has a value equal to one-half of the value of the preceding resistor. A plurality of switches alternately connects each of the plurality of resistor nodes to one of a plurality of low impedance nodes and a low impedance input node associated with the amplifier. Switch control circuitry selectively controls the plurality of switches to transmit the audio signal to the low impedance input node.
|
