摘要 |
<p>Process, voltage, and temperature variations affect the noise generation of an output buffer. Controlling the switching speed of the buffer over these variations also controls the buffer noise, which may be due to ground bounce or other reasons. In one prior-art technique, the current flow behavior of a static circuit is used to control the rise and/or fall times of the output buffer. However, accounting for all possible variations in the factors that influence the switching speed is difficult with a static control circuit. In the inventive technique, the AC switching behavior of a scaled-down buffer (201,202) that is driven by a periodic signal (CLOCK) generates the control voltage (VCP). In this manner, the factors that influence buffer switching speed, including process, voltage, and temperature variations, may be more accurately accounted for. <IMAGE></p> |