VAD detection microphone and method of operating the same

• US 9,113,263 B2
• Filed: 10/23/2014
• Issued: 08/18/2015
• Est. Priority Date: 05/23/2013
• Status: Active Grant

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Frst, Claus Erdmann, Thomsen, Henrik, Deruginsky, Michael, Nandy, Dibyendu, Khamharn, Oddy Nopporn
• Primary Examiner(s): Tsang, Fan
• Assistant Examiner(s): Zhao, Eugene
• Application Number:
  US14/522,158
• Publication Number:
  US 20150043755A1
• Time in Patent Office: 299 Days
• Field of Search: 381/26, 381 91- 95, 381/111, 700/94
• US Class Current: 1/1
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: G10L 15/00 Speech recognition G10L17/00 takes precedence
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10
• CPC Class Codes: H04R 1/08 Mouthpieces; Microphones; Attachments therefor
• CPC Class Codes: H04R 17/02 Microphones
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 2201/003 Mems transducers or their use of the electrostatic type H04R19/005
• CPC Class Codes: H04R 3/00 Circuits for transducers , loudspeakers or microphones
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A microphone includes a microelectromechanical system (MEMS) circuit and an integrated circuit. The MEMS circuit is configured to convert a voice signal into an electrical signal, and the integrated circuit is coupled to the MEMS circuit and is configured to receive the electrical signal. The integrated circuit and the MEMS circuit receive a clock signal from an external host. The clock signal is effective to cause the MEMS circuit and integrated circuit to operate in full system operation mode during a first time period and in a voice activity mode of operation during a second time period. The voice activity mode has a first power consumption and the full system operation mode has a second power consumption. The first power consumption is less than the second power consumption. The integrated circuit is configured to generate an interrupt upon the detection of voice activity, and send the interrupt to the host.

Claims

1. A microphone, the microphone comprising:

a microelectromechanical system (MEMS) circuit that is configured to convert a voice signal into an electrical signal,

an integrated circuit coupled to the MEMS circuit that is configured to receive the electrical signal;

wherein the integrated circuit and the MEMS circuit receive an external clock signal from an external host, the external clock signal being effective to cause the MEMS circuit and integrated circuit to operate in full system operation mode during a first time period and in a voice activity mode of operation during a second time period, the voice activity mode having a first power consumption and the full system operation mode having a second power consumption, the first power consumption being less than the second power consumption, wherein the integrated circuit is configured to generate an electrical interrupt signal upon a detection of voice activity, and send the electrical interrupt signal to the host, and wherein absence of the external clock signal causes the microphone to enter a voice activity detection mode;

wherein the integrated circuit includes a delay buffer that is configured to buffer data included in the electrical signal in order to provide a time delay latency for the integrated circuit to perform sending the electrical interrupt signal, collect noise statistics, or recognize a key phrase in the voice signal;

and the integrated circuit includes an on-chip oscillator disposed at the integrated circuit such that the on-chip oscillator is selectively used by the integrated circuit at least some of the time in place of the external clock signal in order to save power.

2. The microphone of claim 1, wherein host comprises a circuit in a mobile handset, tablet, or personal computer.

3. The microphone of claim 1, wherein the integrated circuit is an application specific integrated circuit (ASIC).

4. The microphone of claim 1, wherein the voice signal comprises a keyword, phrase, or sentence.

5. The microphone of claim 1, wherein the MEMS circuit and the integrated circuit operate in a sleep mode during a third time period.

6. The microphone of claim 1 wherein upon wake-up, buffered data is transmitted over a first transmission line and real time data is transmitted simultaneously over a second and separate output lines.

7. The microphone of claim 1 wherein buffered data is flushed or discarded upon switching modes.

8. The microphone of claim 1, wherein the microphone is over-clocked to catch up buffered data to real time data.

9. The microphone of claim 1 wherein the microphone wake ups and enables data synchronizations of a second microphone either in a buffered or a real time mode.

10. A system for converting voice signals into electrical signals, the system comprising:

an external host;

a microphone, the microphone comprising;

a microelectromechanical system (MEMS) circuit that is configured to convert a voice signal into an electrical signal,

an integrated circuit coupled to the MEMS circuit that is configured to receive the electrical signal;

wherein the integrated circuit and the MEMS circuit receive an external clock signal from the external host, the external clock signal being effective to cause the MEMS circuit and integrated circuit to operate in full system operation mode during a first time period and in a voice activity mode of operation during a second time period, the voice activity mode having a first power consumption and the full system operation mode having a second power consumption, the first power consumption being less than the second power consumption, wherein the integrated circuit is configured to generate an electrical interrupt signal upon a detection of voice activity, and send the electrical interrupt signal to the host, wherein absence of the external clock signal causes the microphone to enter a voice activity detection mode;

wherein the integrated circuit includes a delay buffer that is configured to buffer data included in the electrical signal in order to provide a time delay latency for the integrated circuit to perform sending the electrical interrupt signal, collect noise statistics, or recognize a key phrase in the voice signal;

and wherein the integrated circuit includes an on-chip oscillator disposed at the integrated circuit such that the on-chip oscillator is selectively used by the integrated circuit at least some of the time in place of the external clock signal in order to save power.

11. The system of claim 10, wherein host comprises a circuit in a mobile handset, tablet, or personal computer.

12. The system of claim 10, wherein the integrated circuit is an application specific integrated circuit (ASIC).

13. The system of claim 10, wherein the voice signal comprises a keyword, phrase, or sentence.

14. The system of claim 10, wherein the MEMS circuit and the integrated circuit operate in a sleep mode during a third time period.

15. A method of operating a microphone, the microphone comprising a microelectromechanical system (MEMS) circuit that is configured to convert a voice signal into an electrical signal and an integrated circuit coupled to the MEMS circuit that is configured to receive the electrical signal, the method comprising:

receiving an external clock signal from the external host at the integrated circuit and the MEMS circuit, the external clock signal being effective to cause the MEMS circuit and integrated circuit to operate at a first time in full system operation mode and at a second time in a voice activity mode of operation,

operating in the voice activity mode with a first power consumption during a first time period and operating in the full system operation mode with a second power consumption during a second time period, the first power consumption being less than the second power consumption;

generating an electrical interrupt signal by the integrated circuit upon a detection of voice activity, and sending the electrical interrupt signal to the host;

wherein absence of the external clock signal causes the microphone to enter a voice activity detection mode;

wherein the integrated circuit includes a delay buffer that is configured to buffer data included in the electrical signal in order to provide a time delay latency for the integrated circuit to perform sending the electrical interrupt signal, collect noise statistics, or recognize a key phrase in the voice signal;

and wherein the integrated circuit includes an on-chip oscillator disposed at the integrated circuit such that the on-chip oscillator is selectively used by the integrated circuit at least some of the time in place of the external clock signal in order to save power.

16. The method of claim 15, wherein host comprises a circuit in a mobile handset, tablet, or personal computer.

17. The method of claim 15, wherein the integrated circuit is an application specific integrated circuit (ASIC).

18. The method of claim 15, wherein the voice signal comprises a keyword, phrase, or sentence.

19. The method of claim 15, wherein the MEMS circuit and the integrated circuit operate in a sleep mode during a third time period.