Digital microphone with frequency booster

• US 9,282,406 B2
• Filed: 12/18/2013
• Issued: 03/08/2016
• Est. Priority Date: 12/19/2012
• Status: Expired due to Fees

• Current Assignee: Knowles Electronics Llc (Knowles Corporation)
• Original Assignee: Knowles Electronics Llc (Knowles Corporation)
• Inventors: Bogason, Gudmundur, Thomsen, Henrik
• Primary Examiner(s): Addy, Thjuan K
• Application Number:
  US14/132,471
• Publication Number:
  US 20140177874A1
• Time in Patent Office: 811 Days
• Field of Search: 381/111, 381/67, 381/26, 381/71.1, 381/71.14, 381/56
• US Class Current: 1/1
• CPC Class Codes: H04R 1/005 using digitally weighted transducing elements
• CPC Class Codes: H04R 2201/003 Mems transducers or their use
• CPC Class Codes: H04R 2410/03 Reduction of intrinsic noise in microphones
• CPC Class Codes: H04R 3/04 for correcting frequency response

Abstract

A digital microphone, the microphone includes a microelectromechanical (MEMS) component and a frequency boost component. The MEMS component is configured to convert. sound into an electrical signal. The frequency boost component is configured to receive the electrical signal and ultrasonically boost the electrical signal to create a frequency response. The frequency response does not substantially affect an audio band of interest of the microphone.

Claims

1. A digital microphone, the digital microphone comprising:

a microelectromechanical (MEMS) component, the MEMS component configured to convert sound into an electrical signal; and

an integrated circuit including a frequency boost component, the frequency boost component configured to receive the electrical signal and boost ultrasonic frequency bands within the electrical signal in at least one predetermined step to create a frequency response, the integrated circuit configured to receive a clock external to the digital microphone, the frequency response not substantially affecting an audio band of interest of the microphone, wherein the frequency response is independent of the clock external to the digital microphone.

2. The digital microphone of claim 1, wherein the frequency boost component comprises an ultrasonic boost filter and a frequency detector.

3. The digital microphone of claim 2, wherein the digital microphone includes a sigma-delta analog-to-digital converter and a sigma-delta digital-to digital converter, and wherein the boost filter is implemented in the digital domain, and wherein a first quantization noise in an ultra sound band of the sigma-delta analog-to-digital converter is lower than the a second quantization noise of the sigma-delta digital-to digital converter in the ultra sound band.

4. The digital microphone of claim 1, wherein the MEMS component comprises a back plate and a diaphragm.

5. The digital microphone of claim 1, wherein the digital microphone is configured to couple to an application.

6. The digital microphone of claim 1, further comprising a sigma-delta digital-to digital converter that receives the frequency response.

7. The digital microphone of claim 1, further comprising a sigma-delta analog-to-digital converter.

8. The digital microphone of claim 1, wherein the frequency boost component raises the frequency response above a noise-shaped quantization noise floor.