This paper presents the circuit topology of a second order sigma-delta control of charge trapping for MOS capacitors. With this new topology it is possible to avoid the presence of plateaus that can be found in first-order sigma-delta modulators. Plateaus are unwanted phenomena in which the control is locked for a certain time interval (of unknown duration). In this case the control output is constant and therefore the controlled device is in fact in open-loop configuration. It is shown that the presence of plateaus is avoided in MOS capacitors using the proposed approach.