Touch screen controller, touch screen system including the touch screen controller, and method of operating the touch screen controller

A touch screen controller comprising:

• a driving circuit configured to output a first driving signal to a touch panel in a pen touch mode including a driving period and a subsequent sensing period;
• a boosting circuit configured, in the pen touch mode, to generate a first voltage by performing an internal switching operation based on an input voltage and a first switching signal, and configured to provide the first voltage to the driving circuit;
• a first analog front end circuit configured to receive a first sensing signal generated due to a pen touch in the subsequent sensing period of the pen touch mode and process the first sensing signal;
• and
• a control circuit configured to generate a control signal for controlling the internal switching operation of the boosting circuit,
• wherein the control circuit is configured to interrupt the internal switching operation in the subsequent sensing period.

A method of operating a touch screen controller, the method comprising:

• generating a first voltage by performing an internal switching operation based on a first switching signal, in a pen sensing mode including a driving period and a subsequent sensing period;
• providing a first driving signal generated according to the first voltage to a touch panel;
• generating a second voltage different from the first voltage by performing the internal switching operation based on a second switching signal, in a finger sensing mode;
• and
• providing a second driving signal generated according to the second voltage to the touch panel,
• wherein the first switching signal has a first frequency during the driving period and a second frequency different from the first frequency during the subsequent sensing period, and
• wherein the second switching signal has a third frequency different from the first frequency.