two-point delta-sigma modulation (TPDSM). Two bottleneck problems in the implementation
have been studied rigorously. One is the nonlinear performance of a phase-locked loop
(PLL). The other is the inherent gain and delay mismatches between two modulation points.
Both nonlinear and mismatch factors dominate the modulation accuracy in the closed PLL.
Our formulation can predict the dependencies of modulation accuracy on both factors quite …