| 摘要 |
PURPOSE:To reduce the value of a phase compensating capacity, and to improve a high band characteristic and a through rate by constituting a titled amplifier so that an open loop gain is also switched to make stable condition constant when switching the frequency characteristic of an amplifying circuit. CONSTITUTION:When a switch SW1 selects a power source line 12 side, a current I0 flowing to a current source 13 becomes equal to a current I1 flowing to a transistor QC by a current mirror operation by a transistor QB, diode 15, and the transistor QC, and the first amplifying circuit only is operated. When the switch SW1 selects a ground line 12 side, a transistor QA and a transistor QB are turned on and off, respectively, and a current I2 flows to a transistor QD. In such a case, since I1=0, the second amplifying circuit only is operated. |
