US4975662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Voltage controlled oscillator (VCO) circuit with enhanced frequency selection range
Assignee: Seiko Epson Corp
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Filing: 1989-10-11
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Granted: 1990-12-04
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Expires: 2009-10-11
Abstract
Abstract A voltage controlled oscillator (VCO) circuit includes a current mirror circuit section and oscillator circuit section to provide an oscillation frequency based on the output current of the current mirror circuit section. To vary the oscillation over a wide range, a fixed reference voltage circuit is connected to the current mirror circuit, and either a source follower circuit made of a MOSFET or a FET or an emitter follower circuit made of a bipolar transistor is included is also connected to the current mirror circuit to selectively varying the output current of the current mirror circuit section upon application of a control voltage applied to the follower circuit. Thus, the follower circuit is controlled by a control voltage while the output current of the current mirror circuit varies depending on the magnitude of the control voltage, and, in turn, the oscillating frequency of the oscillator circuit section varies over a wide frequency range, e.g., in excess of 100 dB, in accordance with the output current.
Inventors
- 👤 Kesatoshi Takeuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:05
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/027; H03K3/03; H03K3/353; H03K3/354
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
135 words
A voltage controlled oscillator circuit including a current mirror circuit section and an oscillator circuit section for providing an oscillating frequency based on the output current of the current mirror circuit coupled as an input to said oscillator circuit section, circuit control means in said current mirror circuit section to control said output current based upon a control voltage applied at its input, the improvement comprising a fixed reference voltage applied to said current mirror circuit section in combination with a follower circuit connected as an input to said circuit control means for varying the output current thereof to said oscillator circuit section, the oscillating frequency output of said oscillator circuit section selectively controlled over a wider range of frequencies by selectively controlling the magnitude of said control voltage applied to said follower circuit input.
Claim 2
Dependent Claim
135 words
A voltage controlled oscillator circuit including a current mirror circuit section and an oscillator circuit section for providing an oscillating frequency based on the output current of the current mirror circuit coupled as an input to said oscillator circuit section, circuit control means in said current mirror circuit section to control said output current based upon a control voltage applied at its input, the improvement comprising a fixed reference voltage applied to said current mirror circuit section in combination with a follower circuit connected as an input to said circuit control means for varying the output current thereof to said oscillator circuit section, the oscillating frequency output of said oscillator circuit section selectively controlled over a wider range of frequencies by selectively controlling the magnitude of said control voltage applied to said follower circuit input.
Claim 3
Dependent Claim
24 words
The voltage controlled oscillator circuit according to claim 1, wherein said follower circuit is a source follower circuit comprising either a MOSFET or FET.
Claim 4
Dependent Claim
22 words
The voltage controlled oscillator circuit according to claim 1, wherein (said follower circuit) is an emitter follower circuit comprising a bipolar transistor.
Claim 5
Dependent Claim
16 words
The voltage control oscillator circuit according to claim 1 wherein said range of frequencies exceeds 100dB.
Claim 6
Dependent Claim
124 words
A voltage controlled oscillator circuit having a current mirror circuit and an oscillator circuit wherein the current output from said current mirror circuit is provided as an input to said oscillator circuit to produce an output frequency based upon an input voltage to said current mirror circuit, a voltage input circuit in said current mirror circuit to receive said input voltage to control said current output and provide a selected frequency output from said oscillator circuit based upon a change in said voltage input, the improvement comprising at least one follower circuit coupled to the input of said voltage input circuit and having an input to receive said input voltage extending the range of frequencies capable of being provided at said oscillator circuit output.
Claim 7
Dependent Claim
124 words
A voltage controlled oscillator circuit having a current mirror circuit and an oscillator circuit wherein the current output from said current mirror circuit is provided as an input to said oscillator circuit to produce an output frequency based upon an input voltage to said current mirror circuit, a voltage input circuit in said current mirror circuit to receive said input voltage to control said current output and provide a selected frequency output from said oscillator circuit based upon a change in said voltage input, the improvement comprising at least one follower circuit coupled to the input of said voltage input circuit and having an input to receive said input voltage extending the range of frequencies capable of being provided at said oscillator circuit output.
Claim 8
Dependent Claim
31 words
The voltage controlled oscillator circuit according to claim 5 wherein said voltage input circuit comprises a follower circuit, the tandem combination of said follower circuits providing said extended range of frequency.
Claim 9
Dependent Claim
24 words
The voltage controlled oscillator circuit according to claim 5 wherein said follower circuit is a source follower circuit comprising either a MOSFET or FET.
Claim 10
Dependent Claim
22 words
The voltage controlled oscillator circuit according to claim 5 wherein said follower circuit is an emitter follower circuit comprising a bipolar transistor.
Claim 11
Dependent Claim
16 words
The voltage control oscillator circuit according to claim 5 wherein said range of frequencies exceeds 100dB.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |