US3870898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Frequency-to-voltage converter
Assignee: TDK Micronas GmbH
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Filing: 1974-04-17
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Granted: 1975-03-11
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Expires: 1994-04-17
Abstract
Abstract There is disclosed a frequency-to-voltage converter containing a differential amplifier having an additional transistor whose base to emitter path is connected in parallel to the collector to base path of one of the differential amplifier transistors. The additional transistor is a part of a voltage divider controlling one of the two differential inputs so that the output voltage from the collector of the additional transistor is no longer power supply voltage dependent.
Inventors
- 👤 Wolfgang Hoehn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:26
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; G01R23/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
216 words
A monolithic integrable frequency-to-voltage converter in which a voltage is generated across a capacitor as a function of the pulse duty cycle of a square-wave input signal, said voltage being compared in a threshold circuit with a supply-voltagedependent threshold value, said converter comprising: a supply-voltage source having a first terminal supplying a given polarity supply voltage and a second terminal which is grounded; a symmetrical differential amplifier including a first amplifying transistor and a second amplifying transistor connected between said first and second terminals; a first voltage divider connected between said first and second terminals, said voltage divider having a junction point connected to the base of said first transistor; a second voltage divider including a first resistor connected between said second terminal and the base of said second transistor, a first additional transistor having its emitter connected to the base of said second transistor, its base connected to the collector of said second transistor, and its collector connected by a second resistor to said first terminal; said capacitor being connected between the collector of said first additional amplifier and one of said first and second terminals; and an input circuit for said square-wave input signal to apply said input signal to the collector of said second transistor and the base of said first additional transistor.
Claim 2
Dependent Claim
216 words
A monolithic integrable frequency-to-voltage converter in which a voltage is generated across a capacitor as a function of the pulse duty cycle of a square-wave input signal, said voltage being compared in a threshold circuit with a supply-voltagedependent threshold value, said converter comprising: a supply-voltage source having a first terminal supplying a given polarity supply voltage and a second terminal which is grounded; a symmetrical differential amplifier including a first amplifying transistor and a second amplifying transistor connected between said first and second terminals; a first voltage divider connected between said first and second terminals, said voltage divider having a junction point connected to the base of said first transistor; a second voltage divider including a first resistor connected between said second terminal and the base of said second transistor, a first additional transistor having its emitter connected to the base of said second transistor, its base connected to the collector of said second transistor, and its collector connected by a second resistor to said first terminal; said capacitor being connected between the collector of said first additional amplifier and one of said first and second terminals; and an input circuit for said square-wave input signal to apply said input signal to the collector of said second transistor and the base of said first additional transistor.
Claim 3
Dependent Claim
216 words
A monolithic integrable frequency-to-voltage converter in which a voltage is generated across a capacitor as a function of the pulse duty cycle of a square-wave input signal, said voltage being compared in a threshold circuit with a supply-voltage-dependent threshold value, said converter comprising: a supply-voltage source having a first terminal supplying a given polarity supply voltage and a second terminal which is grounded; a symmetrical differential amplifier including a first amplifying transistor and a second amplifying transistor connected between said first and second terminals; a first voltage divider connected between said first and second terminals, said voltage divider having a junction point connected to the base of said first transistor; a second voltage divider including a first resistor connected between said second terminal and the base of said second transistor, a first additional transistor having its emitter connected to the base of said second transistor, its base connected to the collector of said second transistor, and its collector connected by a second resistor to said first terminal; said capacitor being connected between the collector of said first additional amplifier and one of said first and second terminals; and an input circuit for said square-wave input signal to apply said input signal to the collector of said second transistor and the base of said first additional transistor.
Claim 4
Dependent Claim
216 words
A monolithic integrable frequency-to-voltage converter in which a voltage is generated across a capacitor as a function of the pulse duty cycle of a square-wave input signal, said voltage being compared in a threshold circuit with a supply-voltage-dependent threshold value, said converter comprising: a supply-voltage source having a first terminal supplying a given polarity supply voltage and a second terminal which is grounded; a symmetrical differential amplifier including a first amplifying transistor and a second amplifying transistor connected between said first and second terminals; a first voltage divider connected between said first and second terminals, said voltage divider having a junction point connected to the base of said first transistor; a second voltage divider including a first resistor connected between said second terminal and the base of said second transistor, a first additional transistor having its emitter connected to the base of said second transistor, its base connected to the collector of said second transistor, and its collector connected by a second resistor to said first terminal; said capacitor being connected between the collector of said first additional amplifier and one of said first and second terminals; and an input circuit for said square-wave input signal to apply said input signal to the collector of said second transistor and the base of said first additional transistor.
Claim 5
Dependent Claim
23 words
A converter according to claim 1, wherein said capacitor is connected between the collector of said first additional amplifier and said second tErminal.
Claim 6
Dependent Claim
53 words
A converter according to claim 2, wherein said input circuit includes an input terminal, and a second additional transistor having its base connected to said input terminal, its emitter connected to said second terminal and its collector connected to the collector of said second transistor and the base of said first additional transistor.
Claim 7
Dependent Claim
53 words
A converter according to claim 1, wherein said input circuit includes an input terminal, and a second additional transistor having its base connected to said input terminal, its emitter connected to said second terminal and its collector connected to the collector of said second transistor and the base of said first additional transistor.
Claim 8
Dependent Claim
27 words
A converter according to claim 1, wherein said first terminal supplies a positive polarity supply voltage, and said first, second and first additional transistors are npn transistors.
Claim 9
Dependent Claim
23 words
A converter according to claim 5, wherein said capacitor is connected between the collector of said first additional amplifier and said second terminal.
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) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |