| 摘要 |
PURPOSE: To obtain a compression amplifier which can be operated with a low voltage, and whose circuit can be integrated by making a circuit for generating a bias voltage correspond to a rectifier stage and connecting a reference current source with an adding point between a low-pass filter and the rectifier stage. CONSTITUTION: The feedback branch path of a compression amplifier includes one amplifier SC having a variable amplification factor, a rectifier stage GR' having a corresponding bias voltage generating circuit GV and a low-pass filter TP', and the output of the low-pass filter is fedback to a second quadrant multiplier ZM'. A cut-off voltage is supplied through a bias voltage generating circuit GV to the rectifier stage GR' so that a rectifier action can be established. Then, the output end of the rectifier stage GR' which supplies a current signal the inverse of I1 and the output end of a reference current source RI which generates constant currents I0 are connected with an adding point S. Thus, a compression amplifier which can be operated with a low voltage, and whose circuit can be integrated is obtained. |
