Disclosed is a circuit including: a loop filter to perform digital processing on a signal inputted from an outside; multiple quantizers to output 1-bit signals corresponding to magnitude relationships with thresholds on the basis of the signal after the digital processing by the loop filter; and an averaging circuit to calculate the average of the values shown by the signals outputted by the quantizers, and to feed back the average to the loop filter, in which the thresholds used by the quantizers differ from one another.