US3908173A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential amplifying system with forced differential feedback
Assignee: Motors Liquidation Co
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Filing: 1974-05-13
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Granted: 1975-09-23
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Expires: 1994-05-13
Abstract
Abstract A differential amplifying system including a differential input, differential output first stage coupled to a differential input, single ended output second stage with forced differential feedback from the second stage to the first stage including an in-phase channel and an out-of-phase channel.
Inventors
- 👤 Bruce K Murdock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:16
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/45376; H03F3/45394; H03F1/00; H03F1/56
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
182 words
A differential feedback amplifying system having balanced input capacity comprising: a differential input, differential output amplifier stage including first and second three terminal amplifier means each having input, output, and common terminals, a common resistor interconnecting said common terminals; a first operational amplifier having inverting and non-inverting inputs and a single ended output, means coupling the output terminal of said first amplifier means to said inverting input and coupling the output terminal of said second amplifier means to said non-inverting input; a differential feedback loop including an in-phase channel and an out-of-phase channel, said in-phase channel including a resistor connecting the output of said first operational amplifier to the common terminal of said first amplifier means; said out-of-phase channel including an inverting operational amplifier and a resistor, said resistor interconnecting the output of said inverting operational amplifier with the common terminal of said second amplifier means; and means for receiving input signals at the input terminals of said amplifier means whereby an output signal proportional to the difference of said input signals is produced at the output of said first operational amplifier.
Claim 2
Dependent Claim
182 words
A differential feedback amplifying system having balanced input capacity comprising: a differential input, differential output amplifier stage including first and second three terminal amplifier means each having input, output, and common terminals, a common resistor interconnecting said common terminals; a first operational amplifier having inverting and non-inverting inputs and a single ended output, means coupling the output terminal of said first amplifier means to said inverting input and coupling the output terminal of said second amplifier means to said non-inverting input; a differential feedback loop including an in-phase channel and an out-of-phase channel, said in-phase channel including a resistor connecting the output of said first operational amplifier to the common terminal of said first amplifier means; said out-of-phase channel including an inverting operational amplifier and a resistor, said resistor interconnecting the output of said inverting operational amplifier with the common terminal of said second amplifier means; and means for receiving input signals at the input terminals of said amplifier means whereby an output signal proportional to the difference of said input signals is produced at the output of said first operational amplifier.
Claim 3
Dependent Claim
28 words
The system defined in claim 1 wherein said input, output, and common terminals of said amplifier means are the gate, drain and source electrodes of field effect transistors.
Claim 4
Dependent Claim
51 words
The system defined in claim 2 further including bias means connecting the source electrodes to a negative supply voltage, load means connecting the drain electrode to a positive supply voltage, a compensating capacitor interconnecting said draIn electrodes, and an additional capacitor in parallel with each of said resistors in said channels.
References Cited (Backward Citations)
US3509460A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |