Patent US2664286A successfully refreshed from Google Patents.
Patent US5087833A successfully refreshed from Google Patents.
US5087833A
Expired / Lapsed
US
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Signal switching circuit and signal change-over circuit using the same
Assignee: Advantest Corp
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Filing: 1990-04-09
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Granted: 1992-02-11
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Expires: 2010-04-09
Abstract
Abstract A transmission line is connected in series to the emitter of an output transistor of an ECL circuit which outputs a logical signal, and a pair of series-connected switching diodes is connected to the output end of the transmission line. A parallel switching diode is provided which has its anode connected to the common connection point of the pair of series-connected switching diodes and has its cathode connected to a common potential point. A current pull-in circuit responsive to a control signal and a bias supply circuit are connected to the common connection point. The current pull-in circuit is turned ON to pull in current from the pair of series-connected switching diodes, thereby turning them ON. At this time, the parallel switching diode is turned OFF and the logical signal from the ECL circuit passes through the pair of series-connected switching diodes and is then output. Conversely, when the current pull-in circuit is turned OFF, the pair of series-connected switching diodes is reversely biased, and consequently, no current flows through the emitter of the output transistor of the ECL circuit. As a result of this, the logical signal is not provided on the transmission line.
Inventors
- 👤 Masao Sugai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 05:38
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/74; H03K17/76
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
281 words
A signal switching circuit comprising: an emitter-coupled logical circuit having an output transistor which outputs a logical signal from its emitter; a transmission line having an input end connected in series to the emitter of said output transistor of said emitter-coupled logical circuit and having an output end; switching diode means connected in series to the output end of said transmission line; and bias control means responsive to a control signal to effect ON/OFF control of said switching diode means, said switching diode means, when in the ON state, permitting the passage therethrough of the logical signal for output and, when in the OFF state, operating to prevent the logical signal from being provided on said transmission line from the emitter of said output transistor of said emitter-coupled logical circuit; said switching diode means including: a pair of series-connected switching diodes which have their cathodes interconnected, one of which has its anode connected to the output end of said transmission line and the other which has its anode disposed at an output side of said signal switching circuit; a parallel switching diode having its anode connected to a common connection point of said pair of series-connected switching diodes and having its cathode connected to a common potential point; said bias control means including: current pull-in means responsive to the control signal to pull-in current via said series-connected switching diodes to turn them ON; and bias supply means connected to said common connection point of said pair of series-connected switching diodes, for applying a reverse bias to said pair of series-connected switching diodes and a forward bias to said parallel switching diode when said current pull-in means does not pull in current.
Claim 2
Dependent Claim
281 words
A signal switching circuit comprising: an emitter-coupled logical circuit having an output transistor which outputs a logical signal from its emitter; a transmission line having an input end connected in series to the emitter of said output transistor of said emitter-coupled logical circuit and having an output end; switching diode means connected in series to the output end of said transmission line; and bias control means responsive to a control signal to effect ON/OFF control of said switching diode means, said switching diode means, when in the ON state, permitting the passage therethrough of the logical signal for output and, when in the OFF state, operating to prevent the logical signal from being provided on said transmission line from the emitter of said output transistor of said emitter-coupled logical circuit; said switching diode means including: a pair of series-connected switching diodes which have their cathodes interconnected, one of which has its anode connected to the output end of said transmission line and the other which has its anode disposed at an output side of said signal switching circuit; a parallel switching diode having its anode connected to a common connection point of said pair of series-connected switching diodes and having its cathode connected to a common potential point; said bias control means including: current pull-in means responsive to the control signal to pull-in current via said series-connected switching diodes to turn them ON; and bias supply means connected to said common connection point of said pair of series-connected switching diodes, for applying a reverse bias to said pair of series-connected switching diodes and a forward bias to said parallel switching diode when said current pull-in means does not pull in current.
Claim 3
Dependent Claim
64 words
The signal switching circuit of claim 1, wherein said current pull-in means includes: constant-current source means connected to said common connection point of said pair of series-connected switching diodes, for pulling in a constant current from said pair of series-connected switching diodes in response to the control signal, and a matching resistor connected to the output side of said pair of series-connected switching diodes.
Claim 4
Dependent Claim
58 words
The signal switching circuit of claim 1, wherein said current pull-in means includes: a current pull-in power source; a matching resistor connected at one end to said common connection point of said pair of series-connected switching diodes; and a switching element connected in series between the other end of said matching resistor and said current pull-in power source.
Claim 5
Dependent Claim
236 words
A signal switching circuit comprising: an emitter-coupled logical circuit having first and second output transistors which provide from their emitters first and second logical signals having logic levels which are reversed; first and second transmission lines having input ends connected in series to the emitters of said first and second output transistors and having output ends, for transmitting said first and second logical signals, respectively; first and second switching diodes having anodes connected to the output ends of said first and second transmission lines, respectively; a third switching diode having a cathode connected to the cathode of said first switching diode; current pull-in means connected to the cathodes of said first, second and third switching diodes and responsive to a control signal to pull in current from said first, second and third switching diodes to turn them ON; and bias supply means for applying a reverse bias to said first, second and third switching diodes to hold then OFF when said current pull-in means is OFF; wherein when said current pull-in means is ON, said first and second switching diodes permit the passage therethrough of said first and second logical signals for output and, when said current pull-in means is OFF, said first and second switching diodes operate to prevent said first and second logical signals from being provided on said first and second transmission lines from said emitters of said first and second output transistors.
Claim 6
Dependent Claim
236 words
A signal switching circuit comprising: an emitter-coupled logical circuit having first and second output transistors which provide from their emitters first and second logical signals having logic levels which are reversed; first and second transmission lines having input ends connected in series to the emitters of said first and second output transistors and having output ends, for transmitting said first and second logical signals, respectively; first and second switching diodes having anodes connected to the output ends of said first and second transmission lines, respectively; a third switching diode having a cathode connected to the cathode of said first switching diode; current pull-in means connected to the cathodes of said first, second and third switching diodes and responsive to a control signal to pull in current from said first, second and third switching diodes to turn them ON; and bias supply means for applying a reverse bias to said first, second and third switching diodes to hold then OFF when said current pull-in means is OFF; wherein when said current pull-in means is ON, said first and second switching diodes permit the passage therethrough of said first and second logical signals for output and, when said current pull-in means is OFF, said first and second switching diodes operate to prevent said first and second logical signals from being provided on said first and second transmission lines from said emitters of said first and second output transistors.
Claim 7
Dependent Claim
141 words
The signal switching circuit of claim 4, further including: a fourth switching diode having a cathode connected to the cathode of said second switching diode; first and second matching resistors connected at one end to the anode of said third and fourth switching diodes; current supply means connected to the other ends of said first and second matching resistors, for supplying an ON-state current to said third and fourth switching diodes; and fifth and sixth switching diodes having anodes connected to the cathodes of said first and second switching diodes, respectively, and having cathodes connected to a common potential point, wherein said current pull-in means includes first and second constant-current source means connected to the cathodes of said first and second switching diodes, respectively, and placed under ON/OFF control in response to the control signal to perform the current pull-in operation.
Claim 8
Dependent Claim
37 words
The signal switching circuit of claim 5, further including a differential buffer amplifier having its non-inverting and inverting inputs connected to the anodes of said third and fourth switching diodes and provided with non-inverting and inverting outputs.
Claim 9
Dependent Claim
23 words
The signal switching circuit of claim 5, wherein said first and second transmission lines form a twisted pair line having a characteristic impedance.
Claim 10
Dependent Claim
133 words
The signal switching circuit of claim 4, wherein said current pull-in means includes: first and second matching resistors connected at one end to the cathodes of said first and second switching diodes and connected at the other ends to each other; a current pull-in source; a switching element connected in series between the other ends of said first and second matching resistors and said current pull-in source and placed under ON/OFF control in response to the control signal; an AC grounding capacitance connected between the other ends of said first and second matching resistors and said common potential point; and first On-state current control means connected to the anode of said third switching diode, for supplying an ON-state current which flows through said third switching diode when it is in the ON state.
Claim 11
Dependent Claim
150 words
The signal switching circuit of claim 8, further including: a fourth switching diode having a cathode connected to the cathode of said second switching diode and turned ON by a current pull-in by said current pull-in means; second ON-state current supply means connected to the anode of said fourth switching diode, for supplying an ON-state current which flows through said fourth switching diode when it is in the ON-state; and fifth and sixth switching diodes having anodes connected to the cathodes of said first and second switching diodes, respectively, and having cathodes connected to said common potential point, wherein said bias supply means is connected to the cathodes of said first and second switching diodes and applies a reverse bias to said first second, third and fourth switching diodes, and a forward bias to said fifth and sixth switching diodes when said current pull-in means is in the OFF state.
Claim 12
Dependent Claim
37 words
The signal switching circuit of claim 9, further including a differential buffer amplifier having its non-inverting and inverting inputs connected to the anodes of said third and fourth switching diodes and provided with non-inverting and inverting outputs.
Claim 13
Dependent Claim
23 words
The signal switching circuit of claim 8, wherein said first and second transmission lines for a twisted pair line having a characteristic impedance.
Claim 14
Dependent Claim
23 words
The signal switching circuit of claim 4, wherein said first and second transmission lines form a twisted pair line having a characteristic impedance.
Claim 15
Dependent Claim
150 words
A signal switching circuit comprising: an emitter-coupled logical circuit having an output transistor having an emitter which outputs a logical signal; a transmission line having an input end connected to the emitter of said output transistor of said emitter-coupled logical circuit and having an output end, for transmitting said logical signal; gate means supplied with said logical signal at a first input terminal connected to the output end of said transmission line and supplied at a second input terminal with a control signal for enabling and disabling said gate means; and level holding means supplied with said control signal and having an output connected to said first input terminal of said gate means, so that when said control signal is in a logical state of disabling said gate means, a high-level output is provided to hold said first input terminal of said gate means high-level regardless of said logical signal.
Claim 16
Dependent Claim
150 words
A signal switching circuit comprising: an emitter-coupled logical circuit having an output transistor having an emitter which outputs a logical signal; a transmission line having an input end connected to the emitter of said output transistor of said emitter-coupled logical circuit and having an output end, for transmitting said logical signal; gate means supplied with said logical signal at a first input terminal connected to the output end of said transmission line and supplied at a second input terminal with a control signal for enabling and disabling said gate means; and level holding means supplied with said control signal and having an output connected to said first input terminal of said gate means, so that when said control signal is in a logical state of disabling said gate means, a high-level output is provided to hold said first input terminal of said gate means high-level regardless of said logical signal.
Claim 17
Dependent Claim
281 words
A signal change-over circuit comprising: a plurality of emitter-coupled logical circuits, each having a pair of output transistors which output from their emitters a pair of logical signals having logic levels which are reversed; a plurality of pairs of transmission lines each having an input end connected in series to the emitters of said pair of output transistors of the corresponding one of said emitter-coupled logical circuits and each having an output end, for transmitting said pair of logical signals; a plurality of gate circuits each connected to the output ends of the corresponding one of said pairs of transmission lines, for permitting or inhibiting the passage therethrough of at least one of said pair of logical signals in response to a corresponding control signal; and coupling means for coupling together the outputs of said gate circuits and for outputting at least one of said logical signals which has passed through a selected one of said gate circuits, wherein said gate circuits each include: first and second switching diodes having anodes connected to the output ends of the corresponding one of said pairs of transmission lines; a third switching diode having its cathode connected to the cathode of said first switching diode; current pull-in means connected to the cathodes of said first, second and third switching diodes and responsive to the corresponding one of said control signals to pull in current from said first, second and third switching diodes to turn them ON; and bias supply means whereby when said current pull-in means is in the OFF state, a reverse bias is applied to the cathodes of said first, second and third switching means to hold them in the OFF state.
Claim 18
Dependent Claim
281 words
A signal change-over circuit comprising: a plurality of emitter-coupled logical circuits, each having a pair of output transistors which output from their emitters a pair of logical signals having logic levels which are reversed; a plurality of pairs of transmission lines each having an input end connected in series to the emitters of said pair of output transistors of the corresponding one of said emitter-coupled logical circuits and each having an output end, for transmitting said pair of logical signals; a plurality of gate circuits each connected to the output ends of the corresponding one of said pairs of transmission lines, for permitting or inhibiting the passage therethrough of at least one of said pair of logical signals in response to a corresponding control signal; and coupling means for coupling together the outputs of said gate circuits and for outputting at least one of said logical signals which has passed through a selected one of said gate circuits, wherein said gate circuits each include: first and second switching diodes having anodes connected to the output ends of the corresponding one of said pairs of transmission lines; a third switching diode having its cathode connected to the cathode of said first switching diode; current pull-in means connected to the cathodes of said first, second and third switching diodes and responsive to the corresponding one of said control signals to pull in current from said first, second and third switching diodes to turn them ON; and bias supply means whereby when said current pull-in means is in the OFF state, a reverse bias is applied to the cathodes of said first, second and third switching means to hold them in the OFF state.
Claim 19
Dependent Claim
220 words
A signal change-over circuit comprising: a plurality of emitter-coupled logical circuits, each having a output transistor which outputs a logical signal from its emitter; a plurality of transmission lines each having an input end connected to the emitter of said output transistor of the corresponding one of said emitter-coupled logical circuits and having an output end; a plurality of gate means each supplied with said logical signal at a first input terminal connected to the output end of the corresponding one of said transmission lines and supplied at a second input terminal with a corresponding control signal for enabling and disabling said gate means; a plurality of level holding means each supplied with a corresponding one of said control signals and connected to said first input terminal of the corresponding one of said gate means, so that when said control signal is in a logical state of disabling said gate means, a high-level output is provided to thereby hold said first input terminal of said gate means high-level regardless of said logical signal; coupling means for coupling together the outputs of said plural gate means, wherein one of said gate means is enabled by a selected one of said control signals to permit the passage therethrough of the corresponding one of said logical signals for output via said coupling means.
Claim 20
Dependent Claim
220 words
A signal change-over circuit comprising: a plurality of emitter-coupled logical circuits, each having a output transistor which outputs a logical signal from its emitter; a plurality of transmission lines each having an input end connected to the emitter of said output transistor of the corresponding one of said emitter-coupled logical circuits and having an output end; a plurality of gate means each supplied with said logical signal at a first input terminal connected to the output end of the corresponding one of said transmission lines and supplied at a second input terminal with a corresponding control signal for enabling and disabling said gate means; a plurality of level holding means each supplied with a corresponding one of said control signals and connected to said first input terminal of the corresponding one of said gate means, so that when said control signal is in a logical state of disabling said gate means, a high-level output is provided to thereby hold said first input terminal of said gate means high-level regardless of said logical signal; coupling means for coupling together the outputs of said plural gate means, wherein one of said gate means is enabled by a selected one of said control signals to permit the passage therethrough of the corresponding one of said logical signals for output via said coupling means.
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) | 1995-02-10 | 1995-08-12 | 1996-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-10 | 1999-08-12 | 2000-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-10 | 2003-08-12 | 2004-02-11 | $7700.00 | Window Closed / Lapsed |