A smoothing circuit for realizing the miniaturization and the increase of integration
scale of a circuit and for easily varying attack time and release time. This smoothing
circuit comprises a capacitor, voltage comparator, charging circuit, and discharging
circuit. The voltage comparator compares the terminal voltage of the capacitor
with its input voltage and actuates the charging circuit or the discharging circuit
according to a comparison result. The charging circuit charges the capacitor by
intermittently supplying charging current. The discharging circuit discharges the
capacitor by allowing discharging current to flow intermittently.
