Integration circuit, touch interaction sensing apparatus, and touchscreen apparatus
An integration circuit may include a plurality of switches, at least one operational amplifier, and at least one feedback capacitor, sequentially transfers electrical charges charged in a node capacitor to the feedback capacitor, and integrates the electrical charges. The operational amplifier may be synchronized with a clock signal applied to at least one of the plurality of switches to thereby be operated in one of a normal mode and a low power mode.
1. A touchscreen apparatus comprising:
a panel unit including a plurality of first electrodes extended in a first direction and a plurality of second electrodes extended in a second direction intersecting with the first direction;
a driving circuit unit configured to apply driving signals to the plurality of first electrodes; and
a sensing circuit unit connected to the plurality of second electrodes and configured to detect capacitance formed at intersection points between the plurality of first electrodes and the plurality of second electrodes,
wherein the sensing circuit unit includes:
a plurality of integration circuits each connected to one of the plurality of second electrodes, each of the plurality of integration circuits including a plurality of switches,
at least one operational amplifier, and
at least one feedback capacitor and configured to integrate capacitance,
wherein the operational amplifier is configured to be synchronized with a clock signal applied to at least one of the plurality of switches to be operated in each of a normal mode and a low power mode in a same period of the clock signal, and
wherein the operational amplifier consumes less power in the low power mode than in the normal mode by adjusting an amount of current flowing to at least one transistor included in the operational amplifier.
2. The touchscreen apparatus of claim 1 , wherein the operational amplifier is operated in the low power mode in response to the driving signal being in a high level.
3. The touchscreen apparatus of claim 1 , wherein the operational amplifier is operated in the normal mode in response to capacitance being transferred to the feedback capacitor.
4. The touchscreen apparatus of claim 1 , wherein the operational amplifier is operated in the normal mode in response to electrical charges charged in the feedback capacitor being discharged.