In a first signal conversion circuit, a first electrode of a first capacitor is connected to a first signal line, and a second electrode thereof is connected to a first node. In a second capacitor, a third electrode thereof is connected to a second signal line, and a fourth electrode thereof is connected to a second node. In a first inverting amplifier including a first negative feedback switch, a first input electrode is connected to the first node, and a first output electrode is connected to a third node. In a second inverting amplifier including a second negative feedback switch, a second input electrode is connected to the second node. A first averaging switch is connected between a first node and second node. A second averaging switch is connected between third node and fourth node.