Low-power programmable analog subsystem for acoustic activity detection

A method, comprising:

• receiving a first signal, wherein the first signal is an audio signal;
• providing a first voltage to a first comparator;
• providing the first signal to the first comparator;
• receiving a first comparison signal based on output of the first comparator;
• adjusting the first voltage to a second voltage in view of the first comparison signal;
• receiving a second signal, wherein the second signal is indicative of an audio signal;
• providing the second voltage to the first comparator;
• providing the second signal to the first comparator;
• receiving a second comparison signal based on output of the first comparator, wherein the second comparison signal is generated responsive to the second voltage and the second signal;
• and
• providing a wake-up signal to a processing device responsive to the second comparison signal.

A method, comprising:

• receiving a first signal, wherein the first signal is an audio signal;
• providing a first voltage to a first comparator;
• providing the first signal to the first comparator;
• receiving a first comparison signal based on output of the first comparator;
• adjusting the first voltage to a second voltage in view of the first comparison signal
• providing the first signal to a second comparator;
• providing a third voltage to the second comparator;
• receiving a second comparison signal based on output of the second comparator;
• and
• adjusting the third voltage to a fourth voltage in view of the second comparison signal
• providing a second signal to the first comparator, wherein the second signal is indicative of an audio signal;
• providing the second signal to the second comparator;
• receiving a second comparison signal from the first comparator, wherein the second comparison signal is based on the second signal and the second voltage;
• receiving a third comparison signal from the second comparator, wherein the third comparison signal is based on the second signal and the fourth voltage;
• and
• providing a wake-up signal to a processing device responsive to the second comparison signal and third comparison signal.