There is provided a detection chip including a charging circuit, a discharging circuit, a counter and a processor. The charging circuit provides a first charging current within a first charging interval, and provides a second charging current, smaller than the first charging current, within a second charging interval. The discharging circuit provides a first discharging current within a first discharging interval, and provides a second discharging current, smaller than the first discharging current, within a second discharging interval. The counter counts the second charging interval and the second discharging interval. The processor identifies a touch event according to the second charging interval and the second discharging interval.