Apparatus and method for improved chopping mixer

摘要

An apparatus and method for an improved chopping mixer ( 100 ) having a bipolar mixer stage ( 140 ) for mixing signals (lp, In, LOp, LOn) received thereby; an output chopping stage ( 160 ); and an AC coupling stage ( 150 ) for coupling the mixed signal to the output chopping stage. The signal prior to the chopping output stage is centered at the chopping clock frequency rather than DC. AC coupling allows removal of common mode signal in a desired frequency range. Also, the second order component present on each single ended output will also be DC blocked by the AC coupling capacitors, resulting in improved second order IP2 performance.