US3796942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated circuit frequency to voltage converter
Assignee: Texas Instruments Inc
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Filing: 1973-01-02
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Granted: 1974-03-12
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Expires: 1993-01-02
Abstract
Abstract Disclosed is a frequency to voltage converter especially suitable for integrated circuit application in providing a DC signal having magnitude related to and varying with the frequency of a variable input signal over a wide range of device and environmental conditions. A squaring circuit in response to the variable input signal provides a first train of squared pulses to a pulse generator which generates a second train of pulses time displaced therefrom. A first current generator controls the pulse generator so as to provide the second train of pulses with a predetermined pulse width. A second current source tracking the first current source is responsive to the second pulse train for generating a third pulse train in direct frequency proportion thereto having an amplitude variable so as to compensate for pulse width changes. The third pulse train is accordingly comprised of pulses of substantially constant energy. An integrator thereupon integrates the regulated third pulse train into a DC signal of magnitude varying with the frequency of the input signal.
Inventors
- 👤 B Bynum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:52
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/172
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
236 words
A frequency converter responsive to a variable frequency signal comprising: a. squaring circuit means responsive to said variable signal for generating a first train of squared pulses having frequency related to the frequency of said variable signal and having an amplitude switching between first and second states; b. pulse generator means responsive to said first train of pulses for generating a second train of pulses, each pulse thereof characterized as being actuated by a change of state of said first train and further having selectively programmable width; c. first current generator means for supplying a first control signal to said pulse generator means for controlling pulse width of the pulses thereof and for supplying a second control signal having amplitude directly related to said first control signal; d. switching means responsive to said second pulse train and to said second Control signal for generating a third pulse train in direct frequency proportion thereto, and having an amplitude controlled by said second control signal which is dynamically related to said first control signal, whereby a pulse width change in said second pulse train is offset with an amplitude change in said third pulse train to thereby generate all pulses in said third train having substantially equal energy therein; and e. integrator means responsive to said third pulse train for generating a DC signal having a magnitude related to and varying with the frequency of said variable signal.
Claim 2
Dependent Claim
236 words
A frequency converter responsive to a variable frequency signal comprising: a. squaring circuit means responsive to said variable signal for generating a first train of squared pulses having frequency related to the frequency of said variable signal and having an amplitude switching between first and second states; b. pulse generator means responsive to said first train of pulses for generating a second train of pulses, each pulse thereof characterized as being actuated by a change of state of said first train and further having selectively programmable width; c. first current generator means for supplying a first control signal to said pulse generator means for controlling pulse width of the pulses thereof and for supplying a second control signal having amplitude directly related to said first control signal; d. switching means responsive to said second pulse train and to said second Control signal for generating a third pulse train in direct frequency proportion thereto, and having an amplitude controlled by said second control signal which is dynamically related to said first control signal, whereby a pulse width change in said second pulse train is offset with an amplitude change in said third pulse train to thereby generate all pulses in said third train having substantially equal energy therein; and e. integrator means responsive to said third pulse train for generating a DC signal having a magnitude related to and varying with the frequency of said variable signal.
Claim 3
Dependent Claim
39 words
The combination of claim 1 wherein said pulse generator means comprises a one-shot generator for providing pulses in response to a change of state of said first pulse train and having pulse width controlled by said first control signal.
Claim 4
Dependent Claim
82 words
The combination of claim 1 wherein said pulse generator means comprises: a. a first one-shot generator responsive to said first pulse train for generating first logic pulses having width controlled by said first control signal; b. means for inverting said first pulse train; c. a second one-shot generator for providing second logic pulses responsive to said inverted first pulse train; and d. logic NOR circuit means for logically NORing said first and second logic pulses to thereby provide said second pulse train.
Claim 5
Dependent Claim
30 words
The combination of claim 3 wherein each of said one-shot generators includes a capacitor electrically actuated by said first control signal for controlling pulse width of said second pulse train.
Claim 6
Dependent Claim
33 words
The combination of claim 4 wherein said integrator means comprises: a. a capacitor selectively actuated by said switching means; and b. an operational amplifier coupled to said capacitor for providing said DC signal.
Claim 7
Dependent Claim
27 words
The combination of claim 1 wherein the pulse width of said third pulse train is substantially equal to the respective pulse width of said second pulse train.
Claim 8
Dependent Claim
18 words
The combination of claim 6 wherein the components comprising said frequency converter are included in an integrated circuit.
Claim 9
Dependent Claim
29 words
The combination of claim 1 wherein said switching means includes an output transistor having a collector terminal coupled to said integrator means for providing a relatively high impedance thereto.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |