Apparatus and method for minimizing electromagnetic interference in microcomputing systems

• US 6,252,313 B1
• Filed: 12/15/1997
• Issued: 06/26/2001
• Est. Priority Date: 12/15/1997
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Webb, James, Zhang, Michael T., Lofland, Steve, Weiss, Don
• Primary Examiner(s): Ballato, Josie
• Assistant Examiner(s): DeBeradinis, Robert L.
• Application Number:
  US08/990,902
• Time in Patent Office: 1,289 Days
• Field of Search: 206/709, 206/719, 307/91, 361/737, 361/800, 361/816, 361/818, 174/35.R
• US Class Current: 307/91
• CPC Class Codes: H04B 15/005 Reducing noise, e.g. humm, from the supply
• CPC Class Codes: H04B 15/02 Reducing interference from electric apparatus by means located at or near the interfering apparatus

Abstract

An apparatus and method for minimizing electromagnetic interference in a microcomputing system. The apparatus and method of the present invention are based on the fundamental aspect of providing an EMI shield specifically dimensioned to receive a microprocessor within the microcomputing system. The apparatus and method of the present invention are further based on the aspect of providing at least one ferrite bead along a power delivery path to attenuate any high-frequency leakage current from the microprocessor that results at the resonant frequencies of the EMI shield.

Claims

1. An apparatus, comprising:

a microprocessor;

a power supply to supply electrical power to the microprocessor;

a power delivery path coupled between the microprocessor and the power supply; and

at least one ferrite bead disposed within the power delivery path to attenuate high-frequency current;

wherein said at least one ferrite bead forms a high impedance path at a resonant frequency of an electromagnetic interference shield.

2. The apparatus of claim 1, further comprising:

a Faraday shield disposed around said microprocessor.

3. The apparatus of claim 2, wherein:

said at least one ferrite bead forms a high impedance path at a resonant frequency of the Faraday shield.

4. The apparatus of claim 1, further comprising:

a capacitor coupled to the power delivery path in parallel with the microprocessor.

5. A method, comprising:

disposing at least one ferrite bead in a power delivery path between a power supply and a microprocessor to attenuate high frequency current;

wherein disposing at least one ferrite bead includes forming a high impedance path at a resonant frequency of an electromagnetic interference shield.

6. The method of claim 5, further comprising:

disposing a Faraday shield around said microprocessor.

7. The method of claim 6, wherein:

disposing at least one ferrite bead includes forming a high impedance path at a resonant frequency of the Faraday shield.

8. The method of claim 5, further comprising:

coupling a capacitor to the power delivery path in parallel with the microprocessor.

9. A system, comprising:

a microprocessor card in a microprocessor system;

a microprocessor coupled to the microprocessor card;

a power supply to supply electrical power to the microprocessor;

a power delivery path coupled between the microprocessor and the power supply;

at least one ferrite bead disposed within the power delivery path to attenuate high-frequency current;

wherein said at least one ferrite bead forms a high impedance path at a resonant frequency of an electromagnetic interference shield.

10. The system of claim 9, further comprising:

a Faraday shield disposed around said microprocessor.

11. The system of claim 10, wherein:

said at least one ferrite bead forms a high impedance path at a resonant frequency of the Faraday shield.

12. The system of claim 9, further comprising a capacitor coupled to the power delivery path in parallel with the microprocessor.