| 摘要 |
<p>HYBRID CIRCUIT INCLUDING CAPACITIVE CHARGE-TRANSFER MEANS A hybrid circuit includes a capacitive charge-transfer arrangement, comprising parallel capacitors and series switches, for coupling signals in one or both directions between a four-wire line and a two-wire line. The switches are constituted by VMOS power FETs. In one embodiment, the charge-transfer arrangement is provided in the receive Path to give the desired properties of electrical isolation and unbalanced to balanced conversion of receive path signals. Signals from the two-wire line are coupled to a transmit path of the four-wire line via an attenuating and high-pass filtering arrangement and a differential amplifier, thereby providing good common mode rejection of high voltage signals, especially at power line frequencies. In another embodiment, the charge-transfer arrangement is provided, commonly for the receive and transmit paths, for coupling the two-wire line to the remainder of the hybrid circuit.</p> |
