VAD detection microphone and method of operating the same

A microphone assembly comprising:

• an acoustic sensor;
• an electrical circuit having an input coupled to an output of the acoustic sensor, the electrical circuit including an acoustic activity detector;
• an internal clock signal generator coupled to the electrical circuit;
• a host interface with external connections coupled to the electrical circuit, the host interface including a connection for an external clock signal and data;
• the acoustic activity detector configured to process, in an acoustic activity detection mode, data representing an electrical signal output by the acoustic sensor for acoustic activity when the electrical circuit is clocked by a clock signal from the internal clock signal generator in the absence of an external clock signal on the host interface,
• the electrical circuit configured to provide an interrupt signal to the host interface after detection of an acoustic event, and the electrical circuit configured to control an operating mode of the microphone assembly based on an external clock signal received at the host interface in response to the interrupt signal, the microphone assembly having a plurality of different power consumption modes,
• wherein the electrical circuit is configured to provide the data representing the electrical signal to the host interface when the external clock signal is received at the host interface.

A microphone assembly comprising:

• a microelectromechanical systems (MEMS) transducer;
• an electrical circuit including an acoustic activity detector, an A/D converter and a data buffer, an output of the MEMS transducer coupled to an input of the A/D converter and an output of the A/D converter coupled to the acoustic activity detector and the data buffer;
• an internal clock signal generator coupled to the electrical circuit;
• a host interface with external connections coupled to the electrical circuit, the host interface including a connection for an external clock signal and data;
• the microphone assembly having an acoustic activity detection mode when the electrical circuit is clocked by the internal clock signal generator in the absence of an external clock signal at the host interface, wherein during acoustic activity detection mode the electrical circuit is configured to process data representing an electrical signal output by the MEMS transducer for acoustic activity while data representing the electrical signal output by the MEMS transducer is buffered in the data buffer,
• the electrical circuit configured to provide an interrupt signal to the host interface after detection of an acoustic event and the electrical circuit configured to control an operating mode of the microphone assembly based on an external clock signal received at the host interface in response to the interrupt signal, the microphone assembly having a plurality of different power consumption modes,
• wherein buffered data is provided to the host interface in an operating mode when the external clock signal is received at the host interface.