Patent US3715608A successfully refreshed from Google Patents.
US3715608A
Expired / Lapsed
US
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Programmable circuit and method
Assignee: AT&T Teletype Corp
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Filing: 1970-09-23
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Granted: 1973-02-06
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Expires: 1990-09-23
Abstract
Abstract Specifically, first and second diffused silicon diodes are connected to first and second transistors, respectively, to control the conduction thereof, conduction of the first transistor providing a first output from the circuit and conduction of the second transistor providing a second output from the circuit. One of the diodes is irradiated with fast neutrons to raise its forward voltage drop above that of the other diode. When the first diode is irradiated so that it has a higher forward voltage drop than the second diode, the first transistor is rendered conductive to the exclusion of the conduction of the second transistor to provide a first output from the circuit in response to an input to the circuit, and vice versa. In general, electrical devices with radiation - alterable parameters are selectively irradiated to program the output of a circuit such as a read-only memory.
Inventors
- 👤 C Glorioso
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:31
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/42; G; G11; G11C; G11C17/00; G11C17/06
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
135 words
A method for programming a circuit having first and second electrical devices, the circuit being arranged to provide either a first or a second output in response to an input to the circuit depending on the relative values of an electrical parameter of the devices, the devices being of a type experiencing progressive and permanent unidirectional changes in the parameter over a usable range in response to increasing doses of radiation and initially having nominally identical values of the parameter, which comprises: selectively irradiating one of the devices with a dosage of radiation capable of permanently altering the parameter of that device; and thereafter applying the input to the circuit to provide the first output if the first device has been irradiated and to provide the second output if the second device has been irradiated.
Claim 2
Independent Claim
135 words
A method for programming a circuit having first and second electrical devices, the circuit being arranged to provide either a first or a second output in response to an input to the circuit depending on the relative values of an electrical parameter of the devices, the devices being of a type experiencing progressive and permanent unidirectional changes in the parameter over a usable range in response to increasing doses of radiation and initially having nominally identical values of the parameter, which comprises: selectively irradiating one of the devices with a dosage of radiation capable of permanently altering the parameter of that device; and thereafter applying the input to the circuit to provide the first output if the first device has been irradiated and to provide the second output if the second device has been irradiated.
Claim 3
Independent Claim
135 words
A method for programming a circuit having first and second electrical devices, the circuit being arranged to provide either a first or a second output in response to an input to the circuit depending on the relative values of an electrical parameter of the devices, the devices being of a type experiencing progressive and permanent unidirectional changes in the parameter over a usable range in response to increasing doses of radiation and initially having nominally identical values of the parameter, which comprises: selectively irradiating one of the devices with a dosage of radiation capable of permanently altering the parameter of that device; and thereafter applying the input to the circuit to provide the first output if the first device has been irradiated and to provide the second output if the second device has been irradiated.
Claim 4
Independent Claim
135 words
A method for programming a circuit having first and second electrical devices, the circuit being arranged to provide either a first or a second output in response to an input to the circuit depending on the relative values of an electrical parameter of the devices, the devices being of a type experiencing progressive and permanent unidirectional changes in the parameter over a usable range in response to increasing doses of radiation and initially having nominally identical values of the parameter, which comprises: selectively irradiating one of the devices with a dosage of radiation capable of permanently altering the parameter of that device; and thereafter applying the input to the circuit to provide the first output if the first device has been irradiated and to provide the second output if the second device has been irradiated.
Claim 5
Dependent Claim
13 words
A method as recited in claim 1, wherein the devices are semiconductive devices.
Claim 6
Dependent Claim
51 words
A method as recited in claim 2, wherein the devices are diodes and the parameter is the forward voltage drop, and wherein the irradiating step comprises bombarding the selected diode with fast neutrons to raise the forward voltage drop of that diode above the forward voltage drop of the nonselected diode.
Claim 7
Dependent Claim
18 words
A method as recited in claim 3, wherein the first and the second diodes are diffused silicon diodes.
Claim 8
Independent Claim
150 words
A method for programming a circuit to provide a first output, and then reprogramming the circuit to provide a second output, the circuit having first and second electrical devices and being arranged to provide either a first or a second output in respOnse to an input to the circuit depending on the relative values of an electrical parameter of the devices, the devices initially having nominally identical values of the parameter, which comprises: irradiating the first device to a first degree with radiation capable of altering the parameter parameter that device sufficiently to provide the first output in response comprise bombarding the input; and thereafter irradiating the second device to a greater degree than the first to provide the second output in response to the input, the devices being of a type experiencing a progressive unidirectional change in the parameter over a usable range with increasing doses of the radiation.
Claim 9
Independent Claim
150 words
A method for programming a circuit to provide a first output, and then reprogramming the circuit to provide a second output, the circuit having first and second electrical devices and being arranged to provide either a first or a second output in respOnse to an input to the circuit depending on the relative values of an electrical parameter of the devices, the devices initially having nominally identical values of the parameter, which comprises: irradiating the first device to a first degree with radiation capable of altering the parameter parameter that device sufficiently to provide the first output in response comprise bombarding the input; and thereafter irradiating the second device to a greater degree than the first to provide the second output in response to the input, the devices being of a type experiencing a progressive unidirectional change in the parameter over a usable range with increasing doses of the radiation.
Claim 10
Dependent Claim
61 words
A method as recited in claim 5, wherein the devices are diodes and the parameter is the forward voltage drop, and wherein the irradiating steps comprise bombarding diodes in sequence with fast neutrons, the dosage in the second step being greater than in the first to raise the forward voltage drop of the second diode above that of the first diode.
Claim 11
Dependent Claim
18 words
A method as recited in claim 6, wherein the first and the second diodes are diffused silicon diodes.
Claim 12
Independent Claim
172 words
A method of providing a first or a second output from a circuit in response to the application of an input to the circuit, which comprises: connecting a first diode to a first current switching device to control the conduction thereof, the first diode being of a type experiencing permanent and progressive changes in an electrical parameter thereof with increasing doses of a radiation; connecting a second diode to a second current switching device to control the conduction thereof, the second diode being of a type experiencing permanent and progressive changes in an electrical parameter thereof with increasing doses of a radiation; selectively irradiating one of the diodes with a dosage of radiation to alter the electrical parameter of that diode; and thereafter applying the input to the circuit to cause the first switching device to conduct and to provide the first output if the first diode has been irradiated and to cause the second switching device to conduct and to provide the second output if the second diode has been irradiated.
Claim 13
Independent Claim
172 words
A method of providing a first or a second output from a circuit in response to the application of an input to the circuit, which comprises: connecting a first diode to a first current switching device to control the conduction thereof, the first diode being of a type experiencing permanent and progressive changes in an electrical parameter thereof with increasing doses of a radiation; connecting a second diode to a second current switching device to control the conduction thereof, the second diode being of a type experiencing permanent and progressive changes in an electrical parameter thereof with increasing doses of a radiation; selectively irradiating one of the diodes with a dosage of radiation to alter the electrical parameter of that diode; and thereafter applying the input to the circuit to cause the first switching device to conduct and to provide the first output if the first diode has been irradiated and to cause the second switching device to conduct and to provide the second output if the second diode has been irradiated.
Claim 14
Dependent Claim
57 words
A method as recited in claim 8, wherein the electrical parameter is the forward voltage drop of the diode and wherein selectively irradiating one of the diodes comprises bombarding the selected diode with a dosage of fast neutrons to raise the forward voltage drop of the selected diode above the forward voltage drop of the nonselected diode.
Claim 15
Dependent Claim
29 words
A method a recited in claim 9 wherein: the first and second diodes are diffused silicon diodes; and the first and second current switching devices are transistor switching devices.
Claim 16
Independent Claim
213 words
A method of changing the output of a circuit having two diodes from a first to a second state, the output from the circuit being provided in response to the application of an input to the circuit, the circuit being characterized in that a first state is provided at the output in response to the input if the forward voltage drop of the first diode is greater than the forward voltage drop of the second diode, and vice versa, the circuit initially being characterized in that the first diode has a greater forward voltage drop than the second diode so that the output of the circuit assumes the first state upon the application of the input, and the second diode being of a type which experiences a permanent and progressive unidirectional change in the forward voltage drop thereof in response to increasing doses of a radiation, which comprises: irradiating the second diode with a dosage of radiation to raise the forward voltage drop of the second diode to such an extent that the forward voltage drop of the second diode, after irradiation, is greater than that of the first diode; and applying the input to the circuit, after irradiating the second diode, so that the output of the circuit assumes the second state.
Claim 17
Independent Claim
213 words
A method of changing the output of a circuit having two diodes from a first to a second state, the output from the circuit being provided in response to the application of an input to the circuit, the circuit being characterized in that a first state is provided at the output in response to the input if the forward voltage drop of the first diode is greater than the forward voltage drop of the second diode, and vice versa, the circuit initially being characterized in that the first diode has a greater forward voltage drop than the second diode so that the output of the circuit assumes the first state upon the application of the input, and the second diode being of a type which experiences a permanent and progressive unidirectional change in the forward voltage drop thereof in response to increasing doses of a radiation, which comprises: irradiating the second diode with a dosage of radiation to raise the forward voltage drop of the second diode to such an extent that the forward voltage drop of the second diode, after irradiation, is greater than that of the first diode; and applying the input to the circuit, after irradiating the second diode, so that the output of the circuit assumes the second state.
Claim 18
Dependent Claim
18 words
A method as recIted in claim 11, wherein irradiating the diode comprises bombarding the diode with fast neutrons.
Claim 19
Dependent Claim
14 words
A method as recited in claim 12, wherein the diodes are diffused silicon diodes.
Claim 20
Dependent Claim
134 words
A programmable system for providing either a first or a second output in response to an applied input, which comprises: first and second electrical devices initially having nominally identical values of an electrical parameter, and being of a type experiencing a progressive an irreversible change in the electrical parameter over a usable range with increasing doses of a radiation; means for selectively irradiating one of the devices with a dosage of radiation capable of irreversibly altering the parameter of that device; and means for connecting the devices in a circuit so that the first output is provided in response to the applied input to the circuit if the first device has been irradiated, and so that the second output is provided in response to the applied input if the second device has been irradiated.
Claim 21
Dependent Claim
134 words
A programmable system for providing either a first or a second output in response to an applied input, which comprises: first and second electrical devices initially having nominally identical values of an electrical parameter, and being of a type experiencing a progressive an irreversible change in the electrical parameter over a usable range with increasing doses of a radiation; means for selectively irradiating one of the devices with a dosage of radiation capable of irreversibly altering the parameter of that device; and means for connecting the devices in a circuit so that the first output is provided in response to the applied input to the circuit if the first device has been irradiated, and so that the second output is provided in response to the applied input if the second device has been irradiated.
Claim 22
Dependent Claim
32 words
A system as recited in claim 14, wherein the devices are diodes and the parameter is the forward voltage drop, and wherein the means for irradiating comprises a source of fast neutrons.
Claim 23
Dependent Claim
18 words
A system as recited in claim 15, wherein the first and the second diodes are diffused silicon diodes.
Claim 24
Dependent Claim
182 words
A programmable system for providing either a first or a second output in response to an applied input, which comprises: first and second current switching devices; first and second diodes, the first diode connected to the first switching device to control the conduction thereof and the second diode connected to the second switching device to control the conduction thereof, the diodes being of a type experiencing a progressive and irreversible change in the forward voltage drop thereof over a usable range with increasing doses of a radiation; means for selectively irradiating one of the diodes with a dosage of radiation to increase the forward voltage drop thereof above the forward voltage drop of the nonselected diode; and means for applying a potential across the diodes, the diode having the greater forward voltage drop being responsive to render conductive its associated switching device to the exclusion of the conduction of the other switching device, so that irradiation of the first diode provides a first output from the system and so that irradiation of the second diode provides a second output from the system.
Claim 25
Dependent Claim
182 words
A programmable system for providing either a first or a second output in response to an applied input, which comprises: first and second current switching devices; first and second diodes, the first diode connected to the first switching device to control the conduction thereof and the second diode connected to the second switching device to control the conduction thereof, the diodes being of a type experiencing a progressive and irreversible change in the forward voltage drop thereof over a usable range with increasing doses of a radiation; means for selectively irradiating one of the diodes with a dosage of radiation to increase the forward voltage drop thereof above the forward voltage drop of the nonselected diode; and means for applying a potential across the diodes, the diode having the greater forward voltage drop being responsive to render conductive its associated switching device to the exclusion of the conduction of the other switching device, so that irradiation of the first diode provides a first output from the system and so that irradiation of the second diode provides a second output from the system.
Claim 26
Dependent Claim
18 words
A system as recited in claim 17, wherein the means for irradiating comprises a source of fast neutrons.
Claim 27
Dependent Claim
18 words
A system as recited in claim 18, wherein the first and the second diodes are diffused silicon diodes.
Claim 28
Dependent Claim
22 words
A system as recited in claim 19, wherein the first and second current switching devices are first and second transistor switching devices.
Claim 29
Dependent Claim
157 words
A programmable system for providing either a first or a second state from each of a plurality of outputs, which comprises: at least two pairs of electrical devices, the devices of each pair initially having nominally identical values of an electrical parameter and being of a type experiencing a progressive and irreversible change in the parameter over a usable range with increasing doses of a radiation; means for selectively irradiating one of the devices in each pair of devices with a dosage of radiation capable of irreversibly altering the parameter of that device; and means for connecting the devices in a circuit having a separate output for each pair of devices, so that irradiation of the first diode of a pair provides a first state at its associated output and so that irradiation of the second diode of a pair provides a second state at its associated output, in response to an applied input to the circuit.
Claim 30
Dependent Claim
157 words
A programmable system for providing either a first or a second state from each of a plurality of outputs, which comprises: at least two pairs of electrical devices, the devices of each pair initially having nominally identical values of an electrical parameter and being of a type experiencing a progressive and irreversible change in the parameter over a usable range with increasing doses of a radiation; means for selectively irradiating one of the devices in each pair of devices with a dosage of radiation capable of irreversibly altering the parameter of that device; and means for connecting the devices in a circuit having a separate output for each pair of devices, so that irradiation of the first diode of a pair provides a first state at its associated output and so that irradiation of the second diode of a pair provides a second state at its associated output, in response to an applied input to the circuit.
Claim 31
Dependent Claim
30 words
A system as recited in claim 21, wherein: the devices are diodes; the parameter is the forward voltage drop; and the means for irradiating comprises a source of fast neutrons.
Claim 32
Dependent Claim
14 words
A system as recited in claim 22, wherein the Diodes are diffused silicon diodes.
Claim 33
Dependent Claim
258 words
A programmable system for providing either a first or a second state from each of a plurality of outputs, which comprises: at least two pairs of current switching devices; a separate output associated with each pair of switching devices; a pair of diodes for each pair of switching devices, the first diode of each pair of diodes being connected to the first device of its associated pair of devices to control the conduction thereof, and the second diode of each pair of diodes being connected to the second device of its associated pair of devices to control the conduction thereof, the diodes of each pair initially having a nominally identical forward voltage drop and being of a type experiencing a progressive and irreversible increase in the forward voltage drop with increasing doses of a radiation; means for selectively irradiating one of the diodes in each pair of diodes with a dosage of radiation to irreversibly increase the forward voltage drop thereof above the forward voltage drop of the nonselected diode; and means for applying a potential across each pair of diodes, the diode in each pair of diodes having the greater forward voltage drop being responsive to render conductive its associated switching device to the exclusion of the conduction of the other switching device of the pair, so that irradiation of the first diode of a pair of diodes provides a first state from the associated output and so that irradiation of the second diode of a pair of diodes provides a second state from the associated output.
Claim 34
Dependent Claim
258 words
A programmable system for providing either a first or a second state from each of a plurality of outputs, which comprises: at least two pairs of current switching devices; a separate output associated with each pair of switching devices; a pair of diodes for each pair of switching devices, the first diode of each pair of diodes being connected to the first device of its associated pair of devices to control the conduction thereof, and the second diode of each pair of diodes being connected to the second device of its associated pair of devices to control the conduction thereof, the diodes of each pair initially having a nominally identical forward voltage drop and being of a type experiencing a progressive and irreversible increase in the forward voltage drop with increasing doses of a radiation; means for selectively irradiating one of the diodes in each pair of diodes with a dosage of radiation to irreversibly increase the forward voltage drop thereof above the forward voltage drop of the nonselected diode; and means for applying a potential across each pair of diodes, the diode in each pair of diodes having the greater forward voltage drop being responsive to render conductive its associated switching device to the exclusion of the conduction of the other switching device of the pair, so that irradiation of the first diode of a pair of diodes provides a first state from the associated output and so that irradiation of the second diode of a pair of diodes provides a second state from the associated output.
Claim 35
Dependent Claim
25 words
A system as recited in claim 24, wherein: the means for irradiating comprises a source of fast neutrons; and the diodes are diffused silicon diodes.
Claim 36
Dependent Claim
16 words
A system as recited in claim 25, wherein the current switching devices are transistor switching devices.
Claim 37
Independent Claim
162 words
A method of programming a circuit having at least two pairs of electrical devices, the circuit being arranged to provide either a first or a second state from an output associated with each pair of electrical devices, in response to an input to the circuit, depending on the relative values of an electrical parameter of each device in each pair of devices, the devices in each pair initially having nominally identical values of the parameter and being of a type experiencing a progressive and irreversible change in the parameter with increasing doses of a radiation, which comprises: selectively irradiating one of the devices in each pair of devices with a dosage of radiation capable of irreversibly altering the parameter of that device sufficiently to provide the first state from the associated output if the first device of the pair has been irradiated and to provide the second state from the associated output if the second device of the pair has been irradiated.
Claim 38
Independent Claim
162 words
A method of programming a circuit having at least two pairs of electrical devices, the circuit being arranged to provide either a first or a second state from an output associated with each pair of electrical devices, in response to an input to the circuit, depending on the relative values of an electrical parameter of each device in each pair of devices, the devices in each pair initially having nominally identical values of the parameter and being of a type experiencing a progressive and irreversible change in the parameter with increasing doses of a radiation, which comprises: selectively irradiating one of the devices in each pair of devices with a dosage of radiation capable of irreversibly altering the parameter of that device sufficiently to provide the first state from the associated output if the first device of the pair has been irradiated and to provide the second state from the associated output if the second device of the pair has been irradiated.
Claim 39
Dependent Claim
13 words
A method as recited in claim 27, wherein the devices are semiconductive devices.
Claim 40
Dependent Claim
54 words
A method as recited in claim 28, wherein: the devices are diffused silicon diodes; the parameter is the forward voltage drop; and the irradiating step comprises bombarding the selected diode with a dosage of fast neutrons to raise the forward voltage drop of that diode above the forward voltage drop of the nonselected diode.
Claim 41
Independent Claim
193 words
A method of programming and reprogramming a circuit having at least two pairs of electrical devices, the circuit being arranged to provide either a first or a second state from an output associated with each pair of electrical devices, in response to an input to the circuit, depending upon the relative values of an electrical parameter of each device in each pair of devices, the devices in each pair initially having nominally identical values of the parameter, which comprises: selectively irradiating one of the devices in each pair of devices to a first degree with radiation capable of altering the parameter of that device sufficiently to provide the first state from the associated output if the first device of the pair has been irradiated and to provide the second state from the associated output if the second device of the pair has been irradiated; and thereafter irradiating the other device of each pair to a greater degree than the first to provide the opposite state at the associated output, the devices being of a type experiencing a progressive unidirectional change in the parameter over a usable range with increasing doses of the radiation.
Claim 42
Independent Claim
193 words
A method of programming and reprogramming a circuit having at least two pairs of electrical devices, the circuit being arranged to provide either a first or a second state from an output associated with each pair of electrical devices, in response to an input to the circuit, depending upon the relative values of an electrical parameter of each device in each pair of devices, the devices in each pair initially having nominally identical values of the parameter, which comprises: selectively irradiating one of the devices in each pair of devices to a first degree with radiation capable of altering the parameter of that device sufficiently to provide the first state from the associated output if the first device of the pair has been irradiated and to provide the second state from the associated output if the second device of the pair has been irradiated; and thereafter irradiating the other device of each pair to a greater degree than the first to provide the opposite state at the associated output, the devices being of a type experiencing a progressive unidirectional change in the parameter over a usable range with increasing doses of the radiation.
Claim 43
Dependent Claim
65 words
A method as recited in claim 30, wherein: the devices are diffused silicon diodes; the parameter is the forward voltage drop; the irradiating steps comprise bombarding the diodes in sequence with fast neutrons, the dosage in the second step being greater than in the first to raise the forward voltage drop of the diode irradiated second in each pair above that of the other diode.
Claim 44
Independent Claim
210 words
A method of changing the state of two or more outputs of a circuit having a plurality of outputs from a first to a second state, or vice versa, in response to the application of an input to the circuit, the circuit having a pair of diodes associated with each output and being characterized in that a first state is provided at an output if the forward voltage drop of the first diode of the pair of diodes associated with that output is greater than the forward voltage drop of the second diode of that pair, and vice versa, each diode of each pair of diodes being of a type experiencing a progressive and irreversible increase in the forward voltage drop thereof in response to increasing doses of a radiation, which comprises: selecting in at least two pairs of diodes the diode which has the smaller forward voltage drop; irradiating the selected diodes to such an extend that the forward voltage drop of the selected diode is greater after irradiating than the forward voltage drop of the nonselected diode; and applying the input to the circuit so that the outputs associated with the selected diodes assume a second state if they initially had assumed a first state, and vice versa.
Claim 45
Independent Claim
210 words
A method of changing the state of two or more outputs of a circuit having a plurality of outputs from a first to a second state, or vice versa, in response to the application of an input to the circuit, the circuit having a pair of diodes associated with each output and being characterized in that a first state is provided at an output if the forward voltage drop of the first diode of the pair of diodes associated with that output is greater than the forward voltage drop of the second diode of that pair, and vice versa, each diode of each pair of diodes being of a type experiencing a progressive and irreversible increase in the forward voltage drop thereof in response to increasing doses of a radiation, which comprises: selecting in at least two pairs of diodes the diode which has the smaller forward voltage drop; irradiating the selected diodes to such an extend that the forward voltage drop of the selected diode is greater after irradiating than the forward voltage drop of the nonselected diode; and applying the input to the circuit so that the outputs associated with the selected diodes assume a second state if they initially had assumed a first state, and vice versa.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |