Switched capacitor analog modulo integrator for application in open loop Sigma-Delta modulators
We introduce the switched capacitor analog modulo integrator, which to our knowledge is a new circuit. We introduce the amplitude modulated open loop Sigma Delta modulator (OLSDM), which is an analog modulo integrator followed by a quantizer and a modulo differentiator. The mathematical equivalence between low pass Sigma Delta modulators and OLSDM is explained. Behavioral simulations confirm the equivalence. The necessary circuit, a switched capacitor analog modulo integrator, is explained in detail. Behavioral level simulations in SPICE of the analog modulo integrator verify the function, and prove the concept of amplitude modulated OLSDM.
analog modulo integrator sigma delta modulators switched capacitor circuits