Sideband conductor resonance mitigation

Patent metadata

Field	Value
Publication number	US-9974161-B2
Application number	US-201615079890-A
Country	US
Kind code	B2
Filing date	Mar 24, 2016
Priority date	Jun 25, 2015
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

An apparatus comprising includes a first pair of conductors to carry differential signals, at least one ground conductor neighboring the first pair of conductors, the ground conductor to be connected to a ground plane, and at least one particular conductor to carry sideband signals. The particular conductor is to be connected to a ground plane via a resonance mitigation circuit, and the resonance mitigation circuit comprises a resistor.

First claim

What is claimed is:

1. An apparatus comprising:
a first pair of conductors to carry differential signals;
at least one ground conductor neighboring the first pair of conductors, the ground conductor to be connected to a ground plane, and layout of the conductors is according to a Peripheral Component Interconnect (PCI) Express (PCIe)-based specification; and
at least one particular conductor to carry sideband signals, wherein the particular conductor is to be connected to the ground plane via a resonance mitigation circuit, and the resonance mitigation circuit comprises a resistor, wherein the differential signals comprise high speed signals with frequencies higher than frequencies of the sideband signals.

2. The apparatus of claim 1 , wherein the resonance mitigation circuit further comprises a capacitor in series with the resistor.

3. The apparatus of claim 2 , wherein the resonance mitigation circuit further comprises a tee-connection, and the resistor and capacitor are in a first of at least two branches of the tee-connection.

4. The apparatus of claim 1 , wherein the resonance mitigation circuit is to mitigate resonance manifesting in the particular conductor when the particular conductor has at least one floating connection.

5. The apparatus of claim 4 , wherein the floating connection comprises one of an open connection and a connection with a mismatched impedance.

6. The apparatus of claim 1 , wherein the differential signals comprise signals with frequencies greater than 100 MHz.

7. The apparatus of claim 1 , wherein the resonance mitigation circuit is to damp high frequency resonant energy while allowing operation of the sideband signals.

8. The apparatus of claim 1 , wherein the apparatus comprises a connector comprising the first pair of conductors, ground conductor, and particular conductor.

9. The apparatus of claim 8 , wherein the connector comprises card edge contacts of an add-in card.

10. The apparatus of claim 9 , wherein the add-in card comprises an add-in card compliant with a PCIe-based protocol.

11. The apparatus of claim 8 , wherein the connector comprises a card edge connector to accept an add-in card.

12. The apparatus of claim 8 , wherein the connector comprises card edge contacts of a baseboard card.

13. The apparatus of claim 12 , wherein the baseboard card comprises a baseboard card compliant with a PCIe-based protocol.

14. A method comprising:
sending a differential signal on a pair of conductors of a connector comprising a plurality of conductors, wherein the differential signal radiates energy to another one of the plurality of conductors and layout of the plurality of conductors of the connector is according to a Peripheral Component Interconnect (PCI) Express (PCIe)-based specification;
damping the energy manifesting on the other conductor from the differential signal using a resonance mitigation circuit, wherein the other conductor is coupled to a ground plane via the resonance mitigation circuit, and the resonance mitigation circuit comprises a resistor and a capacitor in series; and
sending a sideband signal on the other conductor, wherein the differential signals comprise high speed signals with frequencies higher than frequencies of the sideband signals.

15. A system comprising:
a board comprising a card edge connector;
an add-in card connected to the card edge connector,
wherein the card edge connector comprises:
a first pair of conductors to carry differential signals;
at least one ground conductor approximate to the first pair of conductors, the ground conductor to be connected to a ground plane; and
at least one particular conductor to carry sideband signals, wherein the particular conductor is to be connected to the ground plane via a resonance mitigation circuit, and the resonance mitigation circuit comprises a resistor in series with a capacitor, wherein the differential signals comprise high speed signals with frequencies higher than frequencies of the sideband signals.

16. The system of claim 15 , wherein the add-in card comprises:
a pair of conductors to correspond to the first pair of conductors and carry the differential signals;
a ground conductor to correspond to the ground conductor of the card edge connector; and
a sideband conductor to correspond to the particular conductor.

17. The system of claim 16 , wherein the sideband conductor is to be connected to a ground plane via a respective resonance mitigation circuit, and the respective resonance mitigation circuit comprises a resistor in series with a capacitor.

18. The system of claim 16 , wherein the sideband conductor is unterminated at the add-in card.

19. The system of claim 15 , wherein the resonance mitigation circuit consists of the resistor connected in series to the capacitor.

Assignees

• Intel Corp

Inventors

• Wig Timothy D
• Krooswyk Steven K
• Wells Marc

Classifications

• H10W44/20

  at high-frequency [HF] or radio frequency [RF] · CPC title

• H05K1/0233

  Filters, inductors or a magnetic substance · CPC title

• H05K1/0219 Primary

  Printed shielding conductors for shielding around or between signal conductors, e.g. coplanar or coaxial printed shielding conductors · CPC title

• H05K1/0245

  Lay-out of balanced signal pairs, e.g. differential lines or twisted lines · CPC title

• H05K1/117

  Pads along the edge of rigid circuit boards, e.g. for pluggable connectors · CPC title