| 摘要 |
PURPOSE:To achieve an excellent phase switching without using an inverter, by connecting an ouput of inphase and opposite phase accompanying an amplification operation as an input signal, through the connection of a switching circuit in forward and reverse manner, in a phase comparator for phase locked loop for audio devices. CONSTITUTION:When a switching circuit SW is operated to a + contact side, a bias voltage is applied to the base of a transistor (TR) Q5 out of the TRs Q5, Q6 of a differential pair. Thus, the TRQ5 is turned on and a prescribed constant current flows to TRs Q1, Q2 out of the TRs Q1, Q2 and Q3, Q4. Thus, a signal applied from an input signal source VIN to the TRQ1 is outputted OUT as an output signal of inphase component accompanying the specified amplification operation. Similarly, when the circuit SW is switched to a - side contact, the bias voltage is applied to the base of the TRQ6 of the differential TR pair Q5, Q6. Then, the specified current flows to the TRs Q3, Q4 and an input signal applied to the TRQ4 via a resistor R2 is outputted as an opposite phase component with the specified amplifying operation. |
