Low power capacitive sensor button

A method, comprising:

• generating a repetitive trigger signal;
• generating an excitation signal having a higher frequency than the repetitive trigger signal;
• in response to the repetitive trigger signal, detecting a presence of a conductive object at a capacitive sensor button by applying the excitation signal to the capacitive sensor button during a measurement period;
• and
• in response to detecting the presence of the conductive object at the capacitive sensor button, transitioning a processing unit from a low power consumption state to a high power consumption state.

A system, comprising:

• a processing unit;
• a capacitive sensor button;
• a timer circuit configured to generate a repetitive trigger signal;
• a low power oscillator block configured to generate an clock signal having a higher frequency than the repetitive trigger signal;
• a sensing block coupled with the timer circuit and the oscillator block and configured to, in response to the repetitive trigger signal, detect a presence of a conductive object at the capacitive sensor button by applying an excitation signal based on the clock signal to the capacitive sensor button during a measurement period;
• and
• a wake logic block coupled with the sensing block and configured to transition the processing unit from a low power consumption state to a high power consumption state in response to the sensing block detecting the presence of the conductive object at the capacitive sensor button.