CA1083667A - Two terminal circuitry for voltage limitation - Google Patents
Two terminal circuitry for voltage limitationInfo
- Publication number
- CA1083667A CA1083667A CA292,047A CA292047A CA1083667A CA 1083667 A CA1083667 A CA 1083667A CA 292047 A CA292047 A CA 292047A CA 1083667 A CA1083667 A CA 1083667A
- Authority
- CA
- Canada
- Prior art keywords
- solid state
- diodes
- state device
- terminals
- pair
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
- H02H9/041—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage using a short-circuiting device
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/30—Modifications for providing a predetermined threshold before switching
Landscapes
- Emergency Protection Circuit Devices (AREA)
- Bipolar Integrated Circuits (AREA)
- Electronic Switches (AREA)
Abstract
Abstract of Disclosure A two terminal solid state device for voltage limitation comprises a controllable current path and a control electrode for the control thereof. A series arrangement of one or more diodes is connected with one of the ends thereof to said control electrode and with the other end thereof to one of said two terminals of the device. The latter is adapted to operate above the combined threshold voltages of said controllable current path and that of said one or more diodes.
Description
83~67 ; Back~round of_the InventionAmong the prior art surge voltage devices those consisting of a gas-filled tube having two electrodes may be mentioned, the tube being connected with one electrode to the line to be pro-tected, and with the other electrode to ground. In operation such surge voltage protectors resemble glo~-lamps. Their voltage limitation occurs only above a voltage of 200 volts. Therefore~
voltage limiting devices of this nature cannot be applied for the protection of circuits including semiconductor devices, be-cause surge voltages of that magnitude would result in a break-down of the semiconductor used in coonection with electronic coupling contacts.
Furthermore~ so-called varistors have been applied as surge voltage protectors. varistors consist of a semiconductor body with two electrodes. The resistance between the electrodes is indepen-dent of the direction of current flow and dependent upon the applied voltage. Varistors have the disadvantage o~ forming non-negligible shunts across the line, or circuitry to be protected, even if the applied voltage is small.
For conducting surge voltages to ground diodes or series arrange-; ments of diodes and/or Zener diodes have been proposed. These are, however, if available space is limited only suitable for dissi-pati~g small power surges. Zener diodes have the further disad-vantage~ particularly if monolithically integrated, of having substantial individual deviations.
It is, therefore, the principal object of this invention to provide surge voltage protective devices not subject to the limitation of the above prior art devices.
A more special object of this invention is to pr~vide means which limit a predetermined voltage approximately to a magnitude in the order of 3 volts, without significant deviations from the re~uired value, and which are not bulky and capable of
voltage limiting devices of this nature cannot be applied for the protection of circuits including semiconductor devices, be-cause surge voltages of that magnitude would result in a break-down of the semiconductor used in coonection with electronic coupling contacts.
Furthermore~ so-called varistors have been applied as surge voltage protectors. varistors consist of a semiconductor body with two electrodes. The resistance between the electrodes is indepen-dent of the direction of current flow and dependent upon the applied voltage. Varistors have the disadvantage o~ forming non-negligible shunts across the line, or circuitry to be protected, even if the applied voltage is small.
For conducting surge voltages to ground diodes or series arrange-; ments of diodes and/or Zener diodes have been proposed. These are, however, if available space is limited only suitable for dissi-pati~g small power surges. Zener diodes have the further disad-vantage~ particularly if monolithically integrated, of having substantial individual deviations.
It is, therefore, the principal object of this invention to provide surge voltage protective devices not subject to the limitation of the above prior art devices.
A more special object of this invention is to pr~vide means which limit a predetermined voltage approximately to a magnitude in the order of 3 volts, without significant deviations from the re~uired value, and which are not bulky and capable of
-2-carrying currents in the order of 1 amp. without substantial voltage drop.
Summary of the Invention The invention relates to a two terminal circuitry for voltage limitation whose conductivity is small below and high above a predetermined threshold voltage. rrhe circuity uses a two terminal solid state device having a controllable current path between its two terminals and further having a control electrode using at least one diode connected with one end there-of to said control electrode of said solid state device andconnected with the other end thereof to one of said terminals of said solid state device.
The improvement according to the present invention comprises a plurality of serially connected diodes becoming conductive when the aggregate threshold voltage thereof and the current path of said solid state device are exceeded, and where-in said plurality of serially connected diodes has at least one tap, at least one by-pass including a series connected resistor and at least one additional diode connected with one end thereof to said tap and with th~ other end thereof to one of said two terminals, and said additional diode having the same polarity orientation as said plural'ity of serially connected diodes controlling said two terminal solid state device.
Brief Description of the Drawings Fig. 1 shows diagrammatically the principle underlying the present invention;
Fig. 2 shows an embodiment of the invention wherein the solid state device is formed by a transistor;
Fig. 3 is an embodiment of the invention wherein the solid state device is formed by a transistor Darlington circuit;
~ 3 ~
Fig.4 is an embodiment of the invention wherein the solid state device is formed by cascade transistors; and Fig.5 is a symmetrical circuit for limiting surge voltages according to the present invention.
Description of Preferred Embodiment Fig.l shows, in principle, a circuitry for voltage limitation according to the present invention. The circuitry includes two terminals 1 and 2, the controllable current path of a solid state device 3 being arranged between said two terminals. The solid state device is controlled by its control electrode 4. A single diode 5 or a series arrangement of diodes 5 is con~ected to control electrode ~. The diode, or diodes 5, are also connected with terminal 1. In this circuitry the diode, or diodes 5, and the gap between terminals 4 and 2 become conductive, when the voltage across diode, or diodes 5, and the voltage across the -3a-` 1~83667 control current path o~ semiconductor device 3 exceeds a predeter-mined value, i.e. the aggregate threshold voltages thereo~.
In the simplest case the solid state device is a transistor, as shown in Fig.2. In Fig.2 the gap ~ormed between the collector and the emitter of transistor 31 ~orms the controllable branch of the transistor and the base ~orms the control electrode. The series arrangement o~ diodes 51,52 is tapped at 8 which will be discussed below more in detail. The above referred-to aggregate threshold voltages which must be exceeded to render the circuitry operative is the ~orward voltage o~ the diode or diodes 52 required to make the same conductive, plus the threshold voltage across the base-emitter gap required to render the transistor 31 conductive. This voltage is about 0.5 volts at the PN-junction of silicon semi-conductor devices.
In Fig.3 the shunt diodes have been deleted. Fig.3 shows merely the well known Darlington circuitry comprising the two transistors 32 and 33. The emitter o~ transistor 32 is connected to the base of transistor 33O ~ig.3 may be derived from Fig.2 by substituting transistor 31 plus its associated circuitry ~or transistor 32 o~
Fig.3. The circuitry o~ Fig.3 has the advantage over that o~ Fig.2 of being capabLe o~ dissipating much higher surge power.
Re~erring now again to Fig.2, connected to tap 8 arranged between diodes 51 and 52 which control transistor 31, is a branch circuit which comprises resistor 6 and at least one diode 7. The other end o~ branch circuit 6~7 is connected to the terminal 2 of a solid state device, in the instant case terminal 2 o~ transistor 31.
I~ this circuitry the diode or diodes 7 are arranged in the same sense or direction as the diodes 51,52 controlling transistor 31 when they are conducting. The threshold voltage of branch 6,7 is less than the aggregate threshold voltages of the control gap of transistor 31 plus the threshold voltage o~ diodes 51 arranged prior to tap 8. The diodes 51 and 52 and the base emitter gap o~ transistor 31 determine, in substance, the limit vo:Ltage of ~83667 the device. The additional series connection of resistor 6 and diode or diodes 7 produces at the initiation range of the diodes a shunt, or by-pass, ~or transistor 31 so that ~or voltages be-low the threshold voltage the transistor 31 is positively blocked.
The shunt comprising resistor 6 and diode or diodes 7 therefore effects a sharper bent in the characteristic of transistor 31 between its blocked condition and its conductive condition, and thus achieves a sharper definition of the voltage limitation of the device.
The circuitry of Figs.l and 2 limit a voltage that is positive in regard to terminal 2. In case that it is necessary to limit positive as well as negative voltages, it is desirable to modify the circuitry according to Fig.2 so as to form a bidirectional circuit. This can readily be achieved in monolithic integration, which allows to achieve a high degree of symmetry in regard to limitatio~ of positive and negative voltage surges. It is, o~
course, possible by the proper choice of diodes to obtain an asymmetrical voltage limitation, i.e. one where the admitted positive and negative voltage peaks differ from each other~
The bidirectional or inverse parallel modification of the circuitry allows to manufacture transistors having high current amplifications also for that kind of operation. This can be achieved with one single transistor limiting both positive and negative surge voltages~ As shown in Fig.S, the two series cir-cuits 51,52 and 6,7 of Fig.2 are doubled, i.e. the circuit includ-ing tap 8, resistor 6, and diodes 7 is arranged in inverse polarity forming tap 81, resistor 61, and diodes 71O Tap 81 of series connected diodes 53 and 5~ corresponds to tap 8 of series connected diodes 51,52 and while diodes 7,53 are connected to terminal 2, diodes 71,51 are connected to terminal 1. The term inverse parallel is applied to indicate that the polarity of diodes 53,5~ and 71 is inverted in regard to that of diodes 51, 52 and 7. It will also be apparent from Fig.5 that the series connection of diodes 53 and 5~ is connected in parallel to the circuit that includes the gap between the basis and the emitter of transistor 31.
When the positive voltage at the terminal 1 exceeds t~e voltage at terminal 2 by the permissible threshold value, diodes 51,52 and 7 become conductive and since the threshold value of diodes 7 is less than the aggregate threshold values of diodes 52 and that of the gap between the base and the emitter of transistor 31, transistor 31 turns into a controlled conductor.
To this end it is necessary t~at the current flowing through resistor 6 - which is in the order of 10 and 100 ohms - and diode 7 produces such a high voltage that transistor 31 is ~ully modulated.
When the voltage at terminal 2 exceeds that at terminal 1, a limitation of the voltage occurs, if diodes 53,5~ and 71 become conductive, and the voltage drop along resistor 61 - which is o~
the same magnitude as resistor 6 - is sufficiently large to cause transistor 31 to operate inversely~
The elements of the circuit-according to the present invention, in particular the diodes and the resistors, are subject only to e~tremely small losses, so as to be able to be implemented as small as techQically possible. The duration during which this semiconductor circuitry is subjected to excessive power is very short, so that the bulk of the semiconductor circuitry is also very small. Consequently several complete circuitries may be on a single semiconductor chipo This is particularly favorable if a plurality of lines or circuits are to be protected from over-voltages.
The small bulk of circuitries according to the present in-vention makes it even possible to integrate in communicationsystems, such as telephone systems, the above described circuitry with electronic coupling contacts~
~ particular advantage of circuits embodying this invention lies in the fact that they may be applied as passive two ~.~836~7 terminal networks. Consequently no additional operating voltages are required. In monolithic integration the con-ventional negative substrate bias may be dispensed with since the substrate current may be neglected because of the lack of transistors which are saturated.
We claim as our invention:
Summary of the Invention The invention relates to a two terminal circuitry for voltage limitation whose conductivity is small below and high above a predetermined threshold voltage. rrhe circuity uses a two terminal solid state device having a controllable current path between its two terminals and further having a control electrode using at least one diode connected with one end there-of to said control electrode of said solid state device andconnected with the other end thereof to one of said terminals of said solid state device.
The improvement according to the present invention comprises a plurality of serially connected diodes becoming conductive when the aggregate threshold voltage thereof and the current path of said solid state device are exceeded, and where-in said plurality of serially connected diodes has at least one tap, at least one by-pass including a series connected resistor and at least one additional diode connected with one end thereof to said tap and with th~ other end thereof to one of said two terminals, and said additional diode having the same polarity orientation as said plural'ity of serially connected diodes controlling said two terminal solid state device.
Brief Description of the Drawings Fig. 1 shows diagrammatically the principle underlying the present invention;
Fig. 2 shows an embodiment of the invention wherein the solid state device is formed by a transistor;
Fig. 3 is an embodiment of the invention wherein the solid state device is formed by a transistor Darlington circuit;
~ 3 ~
Fig.4 is an embodiment of the invention wherein the solid state device is formed by cascade transistors; and Fig.5 is a symmetrical circuit for limiting surge voltages according to the present invention.
Description of Preferred Embodiment Fig.l shows, in principle, a circuitry for voltage limitation according to the present invention. The circuitry includes two terminals 1 and 2, the controllable current path of a solid state device 3 being arranged between said two terminals. The solid state device is controlled by its control electrode 4. A single diode 5 or a series arrangement of diodes 5 is con~ected to control electrode ~. The diode, or diodes 5, are also connected with terminal 1. In this circuitry the diode, or diodes 5, and the gap between terminals 4 and 2 become conductive, when the voltage across diode, or diodes 5, and the voltage across the -3a-` 1~83667 control current path o~ semiconductor device 3 exceeds a predeter-mined value, i.e. the aggregate threshold voltages thereo~.
In the simplest case the solid state device is a transistor, as shown in Fig.2. In Fig.2 the gap ~ormed between the collector and the emitter of transistor 31 ~orms the controllable branch of the transistor and the base ~orms the control electrode. The series arrangement o~ diodes 51,52 is tapped at 8 which will be discussed below more in detail. The above referred-to aggregate threshold voltages which must be exceeded to render the circuitry operative is the ~orward voltage o~ the diode or diodes 52 required to make the same conductive, plus the threshold voltage across the base-emitter gap required to render the transistor 31 conductive. This voltage is about 0.5 volts at the PN-junction of silicon semi-conductor devices.
In Fig.3 the shunt diodes have been deleted. Fig.3 shows merely the well known Darlington circuitry comprising the two transistors 32 and 33. The emitter o~ transistor 32 is connected to the base of transistor 33O ~ig.3 may be derived from Fig.2 by substituting transistor 31 plus its associated circuitry ~or transistor 32 o~
Fig.3. The circuitry o~ Fig.3 has the advantage over that o~ Fig.2 of being capabLe o~ dissipating much higher surge power.
Re~erring now again to Fig.2, connected to tap 8 arranged between diodes 51 and 52 which control transistor 31, is a branch circuit which comprises resistor 6 and at least one diode 7. The other end o~ branch circuit 6~7 is connected to the terminal 2 of a solid state device, in the instant case terminal 2 o~ transistor 31.
I~ this circuitry the diode or diodes 7 are arranged in the same sense or direction as the diodes 51,52 controlling transistor 31 when they are conducting. The threshold voltage of branch 6,7 is less than the aggregate threshold voltages of the control gap of transistor 31 plus the threshold voltage o~ diodes 51 arranged prior to tap 8. The diodes 51 and 52 and the base emitter gap o~ transistor 31 determine, in substance, the limit vo:Ltage of ~83667 the device. The additional series connection of resistor 6 and diode or diodes 7 produces at the initiation range of the diodes a shunt, or by-pass, ~or transistor 31 so that ~or voltages be-low the threshold voltage the transistor 31 is positively blocked.
The shunt comprising resistor 6 and diode or diodes 7 therefore effects a sharper bent in the characteristic of transistor 31 between its blocked condition and its conductive condition, and thus achieves a sharper definition of the voltage limitation of the device.
The circuitry of Figs.l and 2 limit a voltage that is positive in regard to terminal 2. In case that it is necessary to limit positive as well as negative voltages, it is desirable to modify the circuitry according to Fig.2 so as to form a bidirectional circuit. This can readily be achieved in monolithic integration, which allows to achieve a high degree of symmetry in regard to limitatio~ of positive and negative voltage surges. It is, o~
course, possible by the proper choice of diodes to obtain an asymmetrical voltage limitation, i.e. one where the admitted positive and negative voltage peaks differ from each other~
The bidirectional or inverse parallel modification of the circuitry allows to manufacture transistors having high current amplifications also for that kind of operation. This can be achieved with one single transistor limiting both positive and negative surge voltages~ As shown in Fig.S, the two series cir-cuits 51,52 and 6,7 of Fig.2 are doubled, i.e. the circuit includ-ing tap 8, resistor 6, and diodes 7 is arranged in inverse polarity forming tap 81, resistor 61, and diodes 71O Tap 81 of series connected diodes 53 and 5~ corresponds to tap 8 of series connected diodes 51,52 and while diodes 7,53 are connected to terminal 2, diodes 71,51 are connected to terminal 1. The term inverse parallel is applied to indicate that the polarity of diodes 53,5~ and 71 is inverted in regard to that of diodes 51, 52 and 7. It will also be apparent from Fig.5 that the series connection of diodes 53 and 5~ is connected in parallel to the circuit that includes the gap between the basis and the emitter of transistor 31.
When the positive voltage at the terminal 1 exceeds t~e voltage at terminal 2 by the permissible threshold value, diodes 51,52 and 7 become conductive and since the threshold value of diodes 7 is less than the aggregate threshold values of diodes 52 and that of the gap between the base and the emitter of transistor 31, transistor 31 turns into a controlled conductor.
To this end it is necessary t~at the current flowing through resistor 6 - which is in the order of 10 and 100 ohms - and diode 7 produces such a high voltage that transistor 31 is ~ully modulated.
When the voltage at terminal 2 exceeds that at terminal 1, a limitation of the voltage occurs, if diodes 53,5~ and 71 become conductive, and the voltage drop along resistor 61 - which is o~
the same magnitude as resistor 6 - is sufficiently large to cause transistor 31 to operate inversely~
The elements of the circuit-according to the present invention, in particular the diodes and the resistors, are subject only to e~tremely small losses, so as to be able to be implemented as small as techQically possible. The duration during which this semiconductor circuitry is subjected to excessive power is very short, so that the bulk of the semiconductor circuitry is also very small. Consequently several complete circuitries may be on a single semiconductor chipo This is particularly favorable if a plurality of lines or circuits are to be protected from over-voltages.
The small bulk of circuitries according to the present in-vention makes it even possible to integrate in communicationsystems, such as telephone systems, the above described circuitry with electronic coupling contacts~
~ particular advantage of circuits embodying this invention lies in the fact that they may be applied as passive two ~.~836~7 terminal networks. Consequently no additional operating voltages are required. In monolithic integration the con-ventional negative substrate bias may be dispensed with since the substrate current may be neglected because of the lack of transistors which are saturated.
We claim as our invention:
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A two terminal circuitry for voltage limitation whose conductivity is small below and high above a predetermined threshold voltage using a two terminal solid state device having a controllable current path between its two terminals and further having a control electrode using at least one diode connected with one end thereof to said control electrode of said solid state device and connected with the other end thereof to one of the two terminals of said solid state device wherein the novel features comprise a plurality of serially connected diodes becoming conductive when the aggregate threshold voltage thereof and of the current path of said solid state device are exceeded and wherein said plurality of serially connected diodes has at least one tap, at least one by-pass including a series connected resistor and at least one additional diode connected with one end thereof to said one tap and with the other end thereof to one of said two terminals, and said additional diode having the same polarity orientation as said plurality of serially connect-ed diodes controlling said two terminal solid state device.
2. A device as specified in claim 1 wherein said solid state device is a transistor whose gap between the collector thereof and the emitter thereof forms said controllable current path and whose base electrode forms said control electrode.
3. A device as specified in claim 1 wherein said solid state device is formed by a pair of Darlington connected tran-sistors.
4. A device as specified in claim 1 wherein said solid state device is formed by a plurality of cascade-connected transistors, wherein the collector of each stage thereof is con-nected to the base of a subsequent stage, wherein subsequent stages are formed by transistors having alternate types of polarity and wherein the emitters of transistors of subsequent stages are connected to different of said two terminals.
5. A device as specified in claim 1 including two lines of serially connected diodes of opposite polarity, a pair of taps, each of one of said two lines, a pair of by-passes each including a series connection of a resistor and at least one additional diode, one of said pair of by-passes being connected with one of the ends thereof to one of said pair of taps and with the other end thereof to one of said two terminals and the other of said pair of by-passes being connected with one of the ends thereof to the other of said pair of taps and with the other end thereof to the other of said two terminals.
6. A device as specified in claim 1 wherein a plurality of voltage limiting devices are integrated on a common semi-conductor chip.
7. A device as specified in claim 1 wherein a plurality of voltage limiting devices and electronic coupling contacts are integrated on a common semiconductor chip.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2654419A DE2654419C2 (en) | 1976-12-01 | 1976-12-01 | Circuit arrangement for voltage limitation |
| DEP2654419.4 | 1976-12-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1083667A true CA1083667A (en) | 1980-08-12 |
Family
ID=5994391
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA292,047A Expired CA1083667A (en) | 1976-12-01 | 1977-11-30 | Two terminal circuitry for voltage limitation |
Country Status (11)
| Country | Link |
|---|---|
| AT (1) | AT356187B (en) |
| AU (1) | AU2901477A (en) |
| BE (1) | BE861307A (en) |
| CA (1) | CA1083667A (en) |
| DE (1) | DE2654419C2 (en) |
| FR (1) | FR2373181A1 (en) |
| GB (1) | GB1574078A (en) |
| GR (1) | GR59256B (en) |
| IT (1) | IT1090802B (en) |
| NL (1) | NL7708817A (en) |
| SE (1) | SE421094B (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2843213C2 (en) * | 1978-10-04 | 1984-03-29 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Circuit arrangement for voltage limitation |
| US4533846A (en) * | 1979-01-24 | 1985-08-06 | Xicor, Inc. | Integrated circuit high voltage clamping systems |
| SE426002B (en) * | 1980-12-23 | 1982-11-29 | Ellemtel Utvecklings Ab | DEVICE FOR PROTECTION OF A CIRCUIT IN A TELECOMMUNICATION EQUIPMENT |
| FR2512598A1 (en) * | 1981-09-09 | 1983-03-11 | Texas Instruments France | On-chip overvoltage protection for bipolar integrated circuits - uses zener array in base of power transistor shunt across input of bipolar circuit to divert overvoltage |
| DE3301800A1 (en) * | 1983-01-20 | 1984-08-23 | Siemens AG, 1000 Berlin und 8000 München | Protection circuit which can be integrated |
| DE3338124A1 (en) * | 1983-10-20 | 1985-05-02 | Telefunken electronic GmbH, 7100 Heilbronn | NOISE PROTECTION CIRCUIT FOR INTEGRATED CIRCUITS |
| AU580679B2 (en) * | 1985-07-18 | 1989-01-27 | Alcatel Australia Limited | A telephone line switch |
| WO1987000717A1 (en) * | 1985-07-18 | 1987-01-29 | International Standard Electric Corporation | A telephone line switch |
| KR940011757B1 (en) * | 1985-07-18 | 1994-12-23 | 알카텔 엔. 브이. | Telephone line switch |
| GB2206749A (en) * | 1987-07-08 | 1989-01-11 | Sealand Ind Co Ltd | A voltage adaptor |
| JPH02280622A (en) * | 1989-03-16 | 1990-11-16 | Siemens Ag | Transistor circuit |
| JPH02280621A (en) * | 1989-03-16 | 1990-11-16 | Siemens Ag | Transistor circuit |
| EP0677925B1 (en) * | 1994-04-12 | 1998-10-07 | STMicroelectronics S.r.l. | Three-terminal insulated-gate power electronic device with a variable-slope saturated output characteristic depending in a discontinuous way on the output current |
| JP3755675B2 (en) * | 1995-11-20 | 2006-03-15 | ソニー株式会社 | Clamp circuit, CMOS chip IC and contactless information card |
| DE102006021847B4 (en) | 2006-05-10 | 2015-07-02 | Austriamicrosystems Ag | Circuit arrangement for protection against electrostatic discharges |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1538440B2 (en) * | 1966-11-23 | 1972-03-16 | Deutsche Itt Industries Gmbh, 7800 Freiburg | CIRCUIT ARRANGEMENT FOR DC VOLTAGE STABILIZATION ACCORDING TO A Z DIODE |
| FR1575884A (en) * | 1968-06-11 | 1969-07-25 | ||
| US3610948A (en) * | 1969-10-23 | 1971-10-05 | Bell Telephone Labor Inc | Current-switching detector |
| DE2216092B2 (en) * | 1972-04-01 | 1975-10-09 | Semikron Gesellschaft Fuer Gleichrichterbau Und Elektronik Mbh, 8500 Nuernberg | Circuit arrangement for overvoltage limitation with a selenium overvoltage limiter |
| US3846696A (en) * | 1973-07-20 | 1974-11-05 | Rca Corp | Current attenuator |
-
1976
- 1976-12-01 DE DE2654419A patent/DE2654419C2/en not_active Expired
-
1977
- 1977-08-10 NL NL7708817A patent/NL7708817A/en not_active Application Discontinuation
- 1977-09-21 GR GR54403A patent/GR59256B/en unknown
- 1977-09-22 AU AU29014/77A patent/AU2901477A/en active Pending
- 1977-10-04 AT AT705077A patent/AT356187B/en not_active IP Right Cessation
- 1977-10-06 GB GB41646/77A patent/GB1574078A/en not_active Expired
- 1977-11-22 SE SE7713151A patent/SE421094B/en unknown
- 1977-11-29 BE BE183017A patent/BE861307A/en not_active IP Right Cessation
- 1977-11-30 IT IT52014/77A patent/IT1090802B/en active
- 1977-11-30 CA CA292,047A patent/CA1083667A/en not_active Expired
- 1977-11-30 FR FR7736056A patent/FR2373181A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| ATA705077A (en) | 1979-09-15 |
| BE861307A (en) | 1978-03-16 |
| NL7708817A (en) | 1978-06-05 |
| IT1090802B (en) | 1985-06-26 |
| AT356187B (en) | 1980-04-10 |
| DE2654419C2 (en) | 1983-06-09 |
| DE2654419A1 (en) | 1978-06-08 |
| AU2901477A (en) | 1979-03-29 |
| SE7713151L (en) | 1978-06-02 |
| GR59256B (en) | 1977-12-03 |
| GB1574078A (en) | 1980-09-03 |
| SE421094B (en) | 1981-11-23 |
| FR2373181A1 (en) | 1978-06-30 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |