| 摘要 |
<p>PURPOSE: To prevent crosstalk by adding a 2nd reference voltage source and a 2nd selector switch section and interrupting a connection circuit between a selected input terminal and an input terminal not selected. CONSTITUTION: A 2nd selector switch 7 receiving an output signal from a logic control section 5 closes a switch S11 connecting to a reference voltage source Vref1 and opens a switch S12 connecting to a voltage source Vref2, and conversely switches S21-S51 connecting to the power supply Vref1 of remaining switch pairs not connecting to a differential amplifier A1 are open. On the other hand, when an analog signal from an input terminal IN1 from an input section 1 is applied to a noninverting terminal of an amplifier A1, the signal is given to an output terminal 8 via a common load 3. When a 2nd analog signal is received from an input terminal IN2, the switch S21 in switch pairs 21, 22 connecting to an amplifier A2 is open and the S22 is closed, then there is no mutual electric connection. Thus, a 2nd analog signal is not fed to a noninverting terminal of the amplifier A1.</p> |
