Touch sensing apparatus and controller ic thereof

A controller IC of a touch sensing apparatus, comprising:

• an oscillation circuit comprising a capacitor connected to a sensing coil and;
• a digital converter configured to count an oscillation signal output from the oscillation circuit and to output a count value;
• and
• a contact detector comprising
• a delay unit configured to delay the count value by a delay time and to output a delay count value,
• a subtractor configured to subtract the delay count value and the count value and to output a difference value,
• a comparator configured to compare the difference value and a comparison value and to generate a comparison signal, and
• a determiner configured to determining whether an object is in contact according to a high level or a low level of the comparison signal,
• wherein the determiner is further configured to compare the count value and the delay count value, in response to the comparison signal being switched from the low level to the high level, and to determine whether the contact of the object is terminated.