| 摘要 |
Methods and systems for sensing load conditions and for adjusting output current drive according to the sensed load conditions to maintain one or more signal characteristics within a desired range. Load conditions are sensed by monitoring one or more signal characteristics that are affected by load conditions, such as voltage changes with respect to time. Output current drive is then adjusted, as needed, to maintain the one or more desired signal characteristics. In an embodiment, rising and/or falling edge slopes are monitored. For example, a dV/dt may be monitored. The dV/dt can be monitored by coupling a capacitance to the output signal, generating a current with the capacitance, and generating a voltage from the current. The voltage is generally proportional to the dV/dt. Depending upon the load conditions, a supplemental current is generated and/or adjusted and added to the output signal to maintain the desired signal characteristics within a desired range. For example, where dV/dt is monitored, the supplemental current is generated and/or adjusted to maintain the dV/dt within a desired range. In this way, the desired signal characteristic(s) are substantially maintained within the desired range for a range of load values. One or more signal characteristics may be maintained over a load range of 50 pF to 600 pF. Signal characteristics may be sensed and maintained only during rising and falling edges. Signal characteristics maybe separately sensed and maintained for rising and falling edges of data signals.
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