Driving signal generator

A driving signal generator, adapted for a touch display device, comprising:

• a window function code generator, generating a first code corresponding to a window of a first sine wave;
• a sine wave code generator, generating a second code corresponding to a second sine wave, wherein the first sine wave is an envelope of the second sine wave, and a frequency of the second sine wave is higher than a frequency of the first sine wave;
• and
• an operation circuit, coupled to the window function code generator and the sine wave code generator, and performing an operation on the first code and the second code to generate an output code;
• a signal converter, coupled to the operation circuit, generating a touch driving voltage on a driving signal by converting the output code;
• and
• a voltage shifting code generator, generating a code corresponding to a ramp wave;
• a first switch, coupled between the operation circuit and the signal converter, controlled by a first control signal to provide the output code to the signal converter;
• and
• a second switch, coupled between the voltage shifting code generator and the signal converter, controlled by a second control signal to provide the code corresponding to the ramp wave to the signal converter.