| 摘要 |
Systems and methods to achieve an IC audio volume control requiring minimum silicon area and having an accurate volume control gain setting are disclosed. A resistive element in form of a R/2R ladder is deployed between an output node of an operational amplifier and an input node of the circuit. All resistors of said resistive element are unit resistors having a same resistance, wherein said unit resistors are arranged in parallel or series combinations to achieve a resistance desired. A first number of switches are deployed between nodes of the R/2R ladder and an inverting input of the operational amplifier. Furthermore a second number of switches are deployed between nodes within resistor units of the R/2R ladder and the inverting input. The circuit invented could have a single input or a differential input, or a single ended output or a differential output.
|
