Patent ID: 7863934
Filing Date: 2011-01-04
Classification: H03K

Abstract:
1. A method for adjusting driving ability of an output buffer, the output buffer having a plurality of driving ability classes, the method comprising the steps of: (a) initializing the output buffer to have an initial class among the driving ability classes; (b) initializing an output terminal of the output buffer to an initial voltage; (c) inputting a second clock signal via an input terminal; (d) sampling an output voltage outputted from the output terminal to obtain a voltage value at a second time instant in response to a driving edge of a first clock signal; (e) judging whether the voltage value satisfies a predetermined condition; (f) recording and setting the driving ability class of the output buffer if the voltage value satisfies the predetermined condition, wherein, the first clock signal has a frequency that is substantially N times of the second clock signal, and N is an integer greater than 1.