| 摘要 |
PURPOSE: To avoid erroneous operation due to noise caused by an inherent central dead band by providing a duplex differential amplifier at the receiving section of a floating driver and operating it with the differential voltage between sense resistors connected in series with respective control lines. CONSTITUTION: A duplex differential amplifier is built in order to make insensitive to a voltage produced by a common mode current. The amplifier comprises PNP transistors T1, T2 and matching resistors R5, R6 and responds to the differential voltage between V1 and V2. The duplex differential amplifier including the transistors T1, T2 has an inherent central dead band and the transistors T1, T2 are conducted only when the differential voltage between V1 and V2 exceeds Vbe. The dead band avoids the effect of a voltage caused by noise currents on lines 70 and 72. |
