| 摘要 |
PURPOSE:To easily obtain a level compander having a required compression and expansion ratio by providing a power (a) circuit converting a value of a 1st control signal into a value of power (a) and outputting the result as a 2nd control signal. CONSTITUTION:A gain control circuit 3 receives an input signal VIN from an input terminal 1 and receives a control signal I'K from a control terminal 8 and outputs an output signal VOUT from an output terminal 2 and gives either the input signal or the output signal to a level detection circuit 4. The circuit 4 receives a signal VOUT from a level detection input terminal 5 and outputs the result to a control terminal 7 as a control signal IK. The power (a) circuit 9 receives the signal IK from the terminal 7 and outputs the signal I'K to a control terminal 8 as the result of power (a) onto the signal IK. Thus, the signal VOUT from the circuit 3 is outputted as a compressed signal of VIN/(a+1). An expander outputs an output signal VOUT similarly as the expansion of the input signal VIN by a multiple of (1+a). |
