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;
• and
• adjusting the first voltage to a second voltage in view of the first comparison signal.

A circuit, comprising:

• first comparison circuitry, wherein the first comparison circuitry comprises:
• a first comparator, the first comparator receiving a first adjustable comparison voltage;
• a first counter;
• and
• a second comparator, the second comparator receiving a first adjustable comparison value, wherein the first comparison circuitry is provided with a first signal, wherein the first signal is indicative of an audio signal.