US3902140A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digitally controlled oscillator
Assignee: Individual
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Filing: 1972-10-18
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Granted: 1975-08-26
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Expires: 1992-10-18
Abstract
Abstract A digitally controlled oscillator includes an emitter coupled multivibrator with weighted current sources driving the timing capacitor of the multivibrator the weighted current sources being driven by a binary input signal to produce an output frequency corresponding to the binary weight of the input signal. The multivibrator produces output waveforms of either square, triangular or sine waveshapes. The sine wave output is accomplished by the use of anti-parallel diodes in conjunction with the triangular wave output circuitry.
Inventors
- 👤 Alan B Grebene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:29
CPC Classifications
H; H03; H03K; H03K4/00; H03K4/06; H03K3/00; H03K3/02; H03K3/26; H03K3/28; H03K3/281; H03K3/282; H03K3/2821; H03K4/02; H03K4/026; H03K4/08; H03K4/48; H03K4/50; H03K4/52; H03K7/00; H03K7/06; H04; H04L; H04L27/00; H04L27/10; H04L27/12; H03B; H03B2201/00; H03B2201/02; H03B2201/0275; H03B2201/0283
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
351 words
An analog and digitally controlled integrated circuit oscillator responsive to either a digital or analog input signal for producing an output signal having a frequency related to said input signal including a multivibrator having first and second transistors and timing capacitor means connected between said transistors, the charging and discharging of said capacitor means determining the frequency of oscillation of said output signal of said oscillator and including analog current source means responsive to said analog input signal to vary the amount of current produced by said current source means to vary said output signal the level of said current determining said frequency of oscillation, said analog current source means including three legs, two of the legs being coupled to said first and second transistors of said multivibrator and a third leg carrying the remainder of current of such source, said analog current source means also including means responsive to said analog input signal for varying the current in said two legs in an opposite sense relative to said variation of current in said third leg, wherein the improvement comprises: digital current source means for digitally varying said current level including a plurality of constant current source pairs each of said pairs producing a current level related to the relative positional weights of a digital binary input signal, each current source of one of said pair being connected to one of said two legs and similarly each current source of the other of said pair being connected to the other of said two legs said current source pairs being selectively activated by a predetermined binary logic level to provide varying current levels to said capacitor means; said analog current source including common current source means for receiving currents from said three legs and including at least one transistor and said current source pairs each including at least a pair of transistors and means for biasing all of such transistors of said common current source of said analog current source and said transistors of said current source pairs including a source of biasing voltage connected in common to all of such transistors.
Claim 2
Dependent Claim
351 words
An analog and digitally controlled integrated circuit oscillator responsive to either a digital or analog input signal for producing an output signal having a frequency related to said input signal including a multivibrator having first and second transistors and timing capacitor means connected between said transistors, the charging and discharging of said capacitor means determining the frequency of oscillation of said output signal of said oscillator and including analog current source means responsive to said analog input signal to vary the amount of current produced by said current source means to vary said output signal the level of said current determining said frequency of oscillation, said analog current source means including three legs, two of the legs being coupled to said first and second transistors of said multivibrator and a third leg carrying the remainder of current of such source, said analog current source means also including means responsive to said analog input signal for varying the current in said two legs in an opposite sense relative to said variation of current in said third leg, wherein the improvement comprises: digital current source means for digitally varying said current level including a plurality of constant current source pairs each of said pairs producing a current level related to the relative positional weights of a digital binary input signal, each current source of one of said pair being connected to one of said two legs and similarly each current source of the other of said pair being connected to the other of said two legs said current source pairs being selectively activated by a predetermined binary logic level to provide varying current levels to said capacitor means; said analog current source including common current source means for receiving currents from said three legs and including at least one transistor and said current source pairs each including at least a pair of transistors and means for biasing all of such transistors of said common current source of said analog current source and said transistors of said current source pairs including a source of biasing voltage connected in common to all of such transistors.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |