SIGNAL PROCESSING DEVICE AND CONTROL METHOD FOR SIGNAL PROCESSING DEVICE

A signal processing device and a control method therefor comprise: a filter circuit including a first capacitor and reducing a predetermined frequency component of an analog signal; a sample-and-hold circuit including a second capacitor and sampling and holding the analog signal that has passed through the filter circuit; and an AD conversion circuit converting an output signal from the sample-and-hold circuit into a digital signal, and a predetermined voltage is applied to the second capacitor, thereby charging the second capacitor, and the sample-and-hold circuit is then caused to sample the analog signal that has passed through the filter circuit. This suppresses the time required to charge the first capacitor and reduces errors in digital signals.