SEMICONDUCTOR DEVICE HAVING ?S-TYPE MODULATOR, AND SEMICONDUCTOR SYSTEM

摘要

Provided is a semiconductor device comprising an overflow detecting circuit (5) for comparing the output of at least one integrator of a ?S-type modulator (13) with a predetermined value, to output an overflow detection signal, an overflow frequency calculating circuit (6) for calculating an overflow frequency value indicating that the output of the integrator is outside of a normal range, on the basis of the overflow detection signal, to output the overflow frequency, an oscillation deciding circuit (7) for deciding it on the basis of the overflow frequency value whether or not the ?S-type modulator (13) is in an oscillating state, and an oscillation stopping circuit (8) for suppressing the oscillation of the ?S-type modulator (13) in case it is decided by the oscillation deciding circuit (7) that the ?S-type modulator is in the oscillating state. It is decided by determining the frequency, at which the output of the integrator is outside of the normal range, whether the output of the integrator is temporarily brought by noises to the outside of the normal range or oscillated to the outside of the normal range. The oscillation of the ?S-type modulator (13) is suppressed only in the oscillating case.