| 摘要 |
A method and apparatus for analog compensation of driver output signal slew rate against device impedance variation is described. The method includes a signal termination device coupled to a driver output pad. The driver includes a plurality of pull-up devices where each pull-up device is coupled between a driver supply voltage and the signal termination device. In addition, corresponding pull-down devices are coupled between a driver ground and the signal termination device. The driver includes pull-up and pull-down compensation resistive elements coupled in series between selected pull-down/pull-up devices and the signal termination device. Accordingly, the pull-up and pull-down compensation resistive elements provide analog compensation of a driver output signal slew rate against device impedance variation. Also, a slew rate of the driver output signal is within a predetermined slew rate range in order to avoid uncontrolled fast switching as well as unnecessarily slow switching in the driver output signal.
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