An AD converter includes therein a plurality of amplifier circuits such as
first to fourth amplifier circuits. Among the plurality of amplifier
circuits an amplifier circuit that requires higher accuracy is placed
nearer to a power source. An amplifier circuit that receives the first
input of an input analog signal is placed nearest to the power source.
That is, the first amplifier circuit in the embodiment is disposed
closest to the power source. The amplifier circuit that receives the
first input of an input analog signal is disposed closest to the power
source compared to the other amplifier circuits. The first amplifier
circuit, the second amplifier circuit, the third amplifier circuit and
the fourth amplifier circuit in the embodiment are placed in this order
of how close to the power source.