US3886485A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear voltage controlled oscillator including a timing capacitor charged and discharged through current mirror circuits
Assignee: Victor Company of Japan Ltd
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Filing: 1973-11-19
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Granted: 1975-05-27
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Expires: 1993-11-19
Abstract
Abstract A linear voltage controlled oscillator comprises a pair of transistors having mutually connected emitters. The transistors switch ''''ON''''and ''''OFF'''' alternately and repeatedly. A driving means connected to a common point between the emitters of the pair of transistors operates in response to a control signal to control a current and thereby drive the transistors. The output is taken from the base potential of one of the pair of transistors. This base potential varies between two different potentials in accordance with the alternate ON and OFF states of the pair of transistors. The flow of charging and discharging currents, each of an equal current value, is applied to a capacitor connected to the base of the other of the pair of transistors. The pair of transistors are switched ''''ON'''' and ''''OFF'''' responsive to the charging and discharging of the capacitor via current mirror circuits interconnecting the pair of transistors. The control signal controls the oscillation frequency of the linear voltage controlled oscillator.
Inventors
- 👤 Nobuaki Takahashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 12:54
CPC Classifications
H; H03; H03L; H03L7/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
255 words
A linear voltage controlled oscillator comprising: a power source; a pair of transistors having mutually connected emitter electrodes, the base electrode of one of the transistors being connected to a capacitor; first current-mirror circuit means connected between said power source and the collector electrode of the other of the pair of transistors, said first current-mirror circuit means being coupled to the base electrode of the other of the pair of transistors through a first resistor and also coupled to charge the capacitor during intervals while the other of the pair of transistors is conductive; second current-mirror circuit means connected between said power source and the collector electrode of said one of the pair of transistors; third current-mirror circuit means connected between said second current-mirror circuit means and ground, said third currentmirror circuit means being coupled to the base electrode of the other of the transistors through a second resistor and also coupled to discharge the capacitor during intervals while said one of the pair of transistors is conductive; bias circuit means connected between said power source and ground, said bias circuit means being coupled to the base electrode of the other of the pair of transistors through a third resistor; a third transistor connected between the emitter electrodes of said pair of transistors and ground, and means responsive to a control voltage for controlling the current through the third transistor and therefore through said pair of transistors, whereby an oscillating frequency is controlled by a charging current to and a discharging current from the capacitor.
Claim 2
Dependent Claim
255 words
A linear voltage controlled oscillator comprising: a power source; a pair of transistors having mutually connected emitter electrodes, the base electrode of one of the transistors being connected to a capacitor; first current-mirror circuit means connected between said power source and the collector electrode of the other of the pair of transistors, said first current-mirror circuit means being coupled to the base electrode of the other of the pair of transistors through a first resistor and also coupled to charge the capacitor during intervals while the other of the pair of transistors is conductive; second current-mirror circuit means connected between said power source and the collector electrode of said one of the pair of transistors; third current-mirror circuit means connected between said second current-mirror circuit means and ground, said third currentmirror circuit means being coupled to the base electrode of the other of the transistors through a second resistor and also coupled to discharge the capacitor during intervals while said one of the pair of transistors is conductive; bias circuit means connected between said power source and ground, said bias circuit means being coupled to the base electrode of the other of the pair of transistors through a third resistor; a third transistor connected between the emitter electrodes of said pair of transistors and ground, and means responsive to a control voltage for controlling the current through the third transistor and therefore through said pair of transistors, whereby an oscillating frequency is controlled by a charging current to and a discharging current from the capacitor.
Claim 3
Dependent Claim
30 words
A linear voltage controlled oscillator as defined in claim 1 wherein the resistance values of the first and second resistors are larger than the resistance value of the third resistor.
Claim 4
Dependent Claim
199 words
A voltage controlled oscillator comprising: a pair of transistors having their emitters connected together in parallel, said transistors being alternately and repeatedly switched ON and OFF; driving transistor means connected in series with the parallel connected emitters of said pair of transistors, means for operating said driving transistor means in response to an external control signal applied to the base of the driving transistor to control the current value in the parallel emitters for driving said pair of transistors; means operating responsive to the alternate ON and OFF states of said pair of transistors to cause the base potential of one of said pair of transistors to vary between two different potential values; resistors of high resistance value each of which has one side connected to the base of said one of said pair of transistors, the base of the other of said pair of transistors being connected tO a capacitor, means for repeatedly charging and discharging said capacitor; and current-mirror circuits for causing the flow of said charging and discharging currents with a current value equal to the current value of said driving means, the other side of each of said resistors being connected to said current-mirror circuits.
Claim 5
Dependent Claim
199 words
A voltage controlled oscillator comprising: a pair of transistors having their emitters connected together in parallel, said transistors being alternately and repeatedly switched ON and OFF; driving transistor means connected in series with the parallel connected emitters of said pair of transistors, means for operating said driving transistor means in response to an external control signal applied to the base of the driving transistor to control the current value in the parallel emitters for driving said pair of transistors; means operating responsive to the alternate ON and OFF states of said pair of transistors to cause the base potential of one of said pair of transistors to vary between two different potential values; resistors of high resistance value each of which has one side connected to the base of said one of said pair of transistors, the base of the other of said pair of transistors being connected tO a capacitor, means for repeatedly charging and discharging said capacitor; and current-mirror circuits for causing the flow of said charging and discharging currents with a current value equal to the current value of said driving means, the other side of each of said resistors being connected to said current-mirror circuits.
Claim 6
Dependent Claim
59 words
The voltage controlled oscillator as set forth in claim 3 wherein all of the named circuit elements except the capacitor are incorporated within an integrated circuit, said capacitor being disposed outside of said integrated circuit, and an external terminal attached to said integrated circuit for connecting said capacitor to the base of said other of said pair of transistors.
Claim 7
Dependent Claim
35 words
The voltage controlled oscillator as set forth in claim 3 in which said high resistance value is selected to cause the corners of the oscillation output waveform to have a bluntly rounded somewhat rectangular shape.
Claim 8
Dependent Claim
241 words
A voltage controlled oscillator comprising: a pair of transistors having their emitters connected together in parallel, said transistors being alternately and repeatedly switching ON and OFF; driving transistor means connected in series with the parallel connected emitters of said pair of transistors, said driving transistor means comprising a dynamic biasing circuit connected to the parallel circuit of the emitters of said pair of rransistors, means transistors, to said driving transistor means for causing a constant current in said pair of transistors when a specific bias voltage is applied on the base thereof, control means effectively coupled between said driving transistor and the emitters of said pair of transistors and operating in response to a control signal to vary the value of said constant current; means operating responsive to the alternate ON and OFF states of said pair of transistors to cause the base potential of one of said pair of transistors to vary between two different potential values; resistors of high resistance value, each resistor having one side connected to the base of said one of said pair of transistors, the base of the other of said pair of transistors being connected to a capacitor, means for repeatedly charging and discharging said capacitor; and current-mirror circuits for causing the flow of said charging and discharging currents with a current value equal to the current value of said driving means, the other sides of said resistors being connected to said current-mirror circuits.
Claim 9
Dependent Claim
241 words
A voltage controlled oscillator comprising: a pair of transistors having their emitters connected together in parallel, said transistors being alternately and repeatedly switching ON and OFF; driving transistor means connected in series with the parallel connected emitters of said pair of transistors, said driving transistor means comprising a dynamic biasing circuit connected to the parallel circuit of the emitters of said pair of rransistors, means transistors, to said driving transistor means for causing a constant current in said pair of transistors when a specific bias voltage is applied on the base thereof, control means effectively coupled between said driving transistor and the emitters of said pair of transistors and operating in response to a control signal to vary the value of said constant current; means operating responsive to the alternate ON and OFF states of said pair of transistors to cause the base potential of one of said pair of transistors to vary between two different potential values; resistors of high resistance value, each resistor having one side connected to the base of said one of said pair of transistors, the base of the other of said pair of transistors being connected to a capacitor, means for repeatedly charging and discharging said capacitor; and current-mirror circuits for causing the flow of said charging and discharging currents with a current value equal to the current value of said driving means, the other sides of said resistors being connected to said current-mirror circuits.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |