Low capacitance surge protector for high speed data transmission

{
  "publication_number": "US6195245B1",
  "country": "US",
  "kind": "B1",
  "title": "Low capacitance surge protector for high speed data transmission",
  "abstract": "A surge protector circuit and method of protecting electronic equipment which do not load down a circuit at high frequencies and do not degrade a signal in high speed data transmission. A gas tube is connected in parallel with low capacitance diodes and an avalanche semiconductor device, such as a TVS. The diodes and the avalanche semiconductor clamp the voltage transient and allow the slower gas tube more time to fire, discharging the surge. The addition of the low capacitance diodes in series with the avalanche semiconductor, reduces the line-to-line and line-to-ground capacitances of the surge protector and keeps the surge protector circuit from loading down the rest of the circuit and degrading the signal.",
  "claims": [
    "1. A low capacitance surge protector comprising: a gas tube having a first element and a ground element, the first element connected to a first conductor, the ground element connected to ground; a first avalanche semiconductor; and at least a first parallel arrangement of diodes connected in series with the first avalanche semiconductor forming a first series arrangement of components, the first series arrangement of components connected between the first conductor and ground, the at least first parallel arrangement of diodes including at least one pair of diodes, the diodes of the at least one pair of diodes being coupled together in opposite polarity.",
    "2. A low capacitance surge protector as defined by claim 1, further comprising: a second element having one end connected to the gas tube and another end connected to a second conductor; a second avalanche semiconductor; and at least a second parallel arrangement of diodes connected in series with the second avalanche semiconductor forming a second series arrangement of components, the second series arrangement of components connected between the second conductor and ground, the at least second parallel arrangement of diodes including at least one set of two diodes, the diodes of the at least one set of two diodes being coupled together in opposite polarity.",
    "3. A low capacitance surge protector as defined by claim 1, wherein the first series arrangement of components further includes an additional parallel arrangement of diodes connected in series with the first parallel arrangement of diodes and the first avalanche semiconductor, the additional parallel arrangement of diodes including a pair of diodes, the diodes of the pair of diodes being coupled together in opposite polarity.",
    "4. A low capacitance balanced surge protector comprising: a gas tube having a first element, a second element, and a ground element, the first element connected to a first conductor, the second element connected to a second conductor, and the ground element connected to ground; a first series arrangement of diodes connected between a first conductor and second conductor, the first series arrangement of diodes including two diodes, the two diodes being interconnected cathode to cathode; a second series arrangement of diodes connected between a first conductor and second conductor, the second series arrangement of diodes including two diodes, the two diodes being interconnected anode to anode; a first avalanche semiconductor and at least one diode connected in series to the first avalanche semiconductor, the first avalanche semiconductor and at least one diode defining a first series arrangement of components, the first series arrangement of components connected to the interconnected cathodes of the diodes in the first series arrangement of diodes; a second avalanche semiconductor and at least one diode connected in series to the second avalanche semiconductor, the second avalanche semiconductor and at least one diode defining a second series arrangement of components, the second series arrangement of components connected to the interconnected anodes of the diodes in the second series arrangement of diodes.",
    "5. A low capacitance balanced surge protector as defined in claim 4, wherein the anode of the at least one diode in the first series arrangement of components is connected to the first avalanche semiconductor, the cathode of the at least one diode in the first series arrangement of components is connected to ground, the cathode of the at least one diode in the second series arrangement of components is connected to the second avalanche semiconductor, and the anode of the at least one diode in the second series arrangement of components is connected to ground.",
    "6. A low capacitance balanced surge protector as defined in claim 4, wherein the anode of the at least one diode in the second series arrangement of components is connected to the second avalanche semiconductor, the cathode of the at least one diode in the second series arrangement of components is connected to the interconnected anodes of the second series arrangement of diodes, the cathode of the at least one diode in the first series arrangement of components is connected to the first avalanche semiconductor, and the anode of the at least one diode in the first series arrangement of components is connected to the interconnected cathodes of the first series arrangement of diodes.",
    "7. A method of reducing the capacitance of a surge protector, the surge protector having a gas discharge tube and an avalanche semiconductor coupled in parallel with the gas discharge tube, the gas discharge tube and avalanche semiconductor being electrically coupled between an electrical line and ground, which comprises the step of: electrically connecting in series with the avalanche semiconductor at least one parallel arrangement of at least one pair of diodes, a first diode of the at least one pair of diodes being coupled in opposite polarity to a second diode of the at least one pair of diodes, the at least one pair of diodes of the parallel arrangement having a total capacitance associated therewith, the avalanche semiconductor having a capacitance associated therewith, the total capacitance of the parallel arrangement and capacitance of the avalanche semiconductor combining in series, thereby reducing the capacitance of the surge protector between the electrical line and ground.",
    "8. A method of reducing the capacitance of a surge protector as defined in claim 7, wherein each diode of the at least one pair of diodes is a fast recovery diode.",
    "9. A method of reducing the capacitance of a surge protector the surge protector having a three element gas tube, a first avalanche semiconductor, and a second avalanche semiconductor, the three element gas tube having a first element electrically coupled to a first conductor, a second element electrically coupled to a second conductor, and a ground element electrically coupled to ground, the first avalanche semiconductor being electrically coupled between the first conductor and ground, and the second avalanche semiconductor being electrically coupled between the second conductor and ground, which comprises the step of: electrically connecting in series with the first avalanche semiconductor at least one parallel arrangement of at least one pair of diodes, a first diode of the at least one pair of diodes being coupled in opposite polarity to a second diode of the at least one pair of diodes, the at least one pair of diodes of the parallel arrangement having a total capacitance associated therewith, the first avalanche semiconductor having a capacitance associated therewith, the total capacitance of the parallel arrangement and capacitance of the first avalanche semiconductor combining in series, thereby reducing the capacitance of the surge protector between the first conductor and ground; electrically connecting in series with the second avalanche semiconductor at least one parallel arrangement of least one set of diodes, a first diode of the at least one set of diodes being coupled in opposite polarity to a second diode of the at least one set of diodes, the at least one set of diodes of the parallel arrangement having a total capacitance associated therewith, the second avalanche semiconductor having a capacitance associated therewith, the total capacitance of the parallel arrangement and capacitance of the second avalanche semiconductor combining in series, thereby reducing the capacitance of the surge protector between the second electrical line and ground.",
    "10. A method of reducing the capacitance of a surge protector as defined in claim 9, wherein each diode is a fast recovery diode.",
    "11. A method of reducing the capacitance of a surge protector, the surge protector having a gas tube and an avalanche semiconductor coupled in parallel with the gas tube, the gas tube and avalanche semiconductor being electrically coupled between an electrical line and ground, which comprises the step of: electrically connecting in series with the avalanche semiconductor at least one parallel arrangement of at least one pair of diodes, the one diode of the at least one pair of diodes being coupled in opposite polarity to the other diode of the at least one pair of diodes, the at least one pair of diodes of the parallel arrangement having a total capacitance associated therewith, the avalanche semiconductor having a capacitance associated therewith, the total capacitance of the parallel arrangement and capacitance of the avalanche semiconductor combining in series, the resulting total capacitance being calculated by C T ′ = 1 1 C P + 1 C A where C T ′ is the capacitance between the electrical line and ground, C P is the capacitance the parallel arrangement, and C A is the capacitance of the avalanche semiconductor, thereby reducing the capacitance of the surge protector between the electrical line and ground."
  ],
  "description_excerpt": "This application claims the benefit of United States provisional patent application Ser. No. 60/087,323, filed May 29, 1998, entitled “Low Capacitance Surge Protector for High Speed Data Transmission,” the disclosure of which is incorporated herein by reference.\n\n1. Field of the Invention\n\nThis invention relates to methods and apparatus for suppressing transient voltages and current spikes on high speed transmission lines for the purpose of protecting electronic equipment.\n\n2. Description of the Prior Art\n\nPrior art systems for protecting electrical equipment from the damaging effects of voltage transients and current spikes associated with energy surges are well known. Such systems have included the use of gas dissipating tubes, semiconductor devices, or some combination thereof.\n\nGas dissipating tubes, or spark gaps, dissipate energy by producing an electrical arcing to ground. This arcing occurs through the ionization of a gas of known dielectric strength during an electrical surge condition.\n\nWhile gas dissipating tubes provide sufficient suppression for most energy surges, their relatively slow response time results in a failure to suppress fast rise time voltage transients and current spikes. Such transients and spikes are capable of destroying electrical equipment connected to the electrical line upon which the voltage transients and current spikes are induced.\n\nFIG. 1 shows a conventional surge protector which employs a gas dissipating tube 2 connected between two electrical transmission lines 4, 6, which lines carry signals to electronic equipment, such as computer or telephony equipment, connected thereto.",
  "cpc": [
    "H02H 9/06",
    "H04M 3/18"
  ],
  "ipc": [
    "H02H 9/06",
    "H04M 3/18"
  ],
  "assignees": [
    "Porta Systems Corp"
  ],
  "inventors": [
    "Peter Kobsa"
  ],
  "filing_date": "1999-05-28",
  "publication_date": "2001-02-27",
  "grant_date": "2001-02-27",
  "priority_date": "1998-05-29",
  "application_number": "US-32198999-A",
  "family_id": "22204493",
  "cited_by_count": 43,
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}