Filter circuit

A filter circuit comprising:

• an input terminal to which a signal is input;
• an output terminal configured to output an output value in accordance with an input value of the signal;
• a memory configured to store an input value and an output value;
• and
• a processor configured to
• compare an input value and an output value, and
• correct an output value in accordance with an output of comparing,
• wherein
• the processor is further configured to
• compare a current input value with a last-time output value,
• add a first correction value to the current input value and to the last-time output value if a comparison result between the current input value and the last-time output value is greater than a predetermined value, and add a second correction value smaller than the first correction value to the current input value and to the last-time output value if the comparison result is smaller than or equal to the predetermined value, and
• calculate a current output value based on the current input value and the last-time output value to each of which the first correction value or the second correction value has been added.