Patent ID: 7155164

Claim:
A pre-emphasis circuit comprising: a first amplifier operable to amplify a signal using a first amplifier current (I M ), the first amplifier containing M first driver cells, each of the M first driver cells operable to amplify the signal and consume a portion of the first amplifier current, M being an number greater than zero; a second amplifier operable to amplify a delayed version of the signal using a second amplifier current (I P ), the second amplifier containing P second driver cells, each of the P second driver cells operable to amplify the delayed version of the signal and consume a portion of the second amplifier current (I P ), P being a number greater than zero; and a logic circuit operable to change a pre-emphasis ratio (a) of the pre-emphasis circuit including switching off one or more of the M first driver cells and switching on a corresponding one or more of the P second driver cells, such that a total current consumption of the first amplifier and the second amplifier (I M +I P ) remains substantially constant.