| 摘要 |
A power efficient transmitter with a high voltage swing capability for sending data along long backplanes is disclosed. The transmitter circuit includes i) a current switching, current mode logic (CML) type driver (transitors M5-M8) connected to the transmitter output terminals TXP & TXN, and ii) a low-voltage differential signal (LVDS) type driver (transistors M1-M4) having an output node connected to the transmitter output TXP & TXN via a terminating load (resistors Rt). In a standard configuration, the LVDS output node would determine the common mode or receiver bias voltage. In the present invention, the LVDS type stage is switched by the driver input signal (INP, INN) in synchronism with the CML type stage to establish at the LVDS output node a voltage that is substantially the same as that which the ac driven leg of a CML type driver would take up, thereby reducing current through, and power loss in, the terminating resistors Rt.
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