| 摘要 |
<p>An output buffer circuit for driving a transmission line (7) comprises a switch stage (1) including switches for connecting the output of the switch stage with the input of the switch stage in accordance with digital data (din). First impedance means (21) adjustable in accordance with a control signal (sci) are connected to the switch stage. Moreover, monitor impedance means are provided, an impedance of which is adjustable in accordance with a monitor impedance control signal. The first impedance means is connected to receive at its impedance control input a control signal derived from a control signal applied to monitor impedance means. The monitor impedance means constitutes a replica of the first impedance means and allows monitoring and controlling of the first impedance means, such that the output impedance of the switch stage may be adjusted or controlled.</p> |
