| 摘要 |
PURPOSE:To obtain a PIN attenuator circuit in which no transient noise takes place and excellent tracking performance is provided against the change in a digital control voltage. CONSTITUTION:The PIN attenuator circuit whose attenuation is controlled by the control voltage applied to its PIN diode is provided with a DC power supply 2 supplying a reference voltage, an operational amplifier 3 to be supplied the reference voltage, whose output voltage is applied to the PIN diode as a control voltage and a feedback resistance circuit 4 connected between an input terminal and an output terminal of the operational amplifier 3. Then the resistance of the feedback resistor circuit 4 is changed by a digital control signal controlling the attenuation. |
