US3753137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amplifier
Assignee: Telefunken Electronic GmbH
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Filing: 1971-03-12
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Granted: 1973-08-14
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Expires: 1991-03-12
Abstract
Abstract An amplifier comprises a class-B push-pull transistor output stage controlled by a driver transistor, means for maintaining the quiescent collector current of the output stage transistors independent of temperature fluctuations in the output stage transistors, the load resistance of the driver transistor being provided by the collector-emitter path of an additional transistor. A constant current supply is connected to the base of the additional transistor such that its collector-emitter voltage and thus the load resistance of the driver transistor varies substantially in proportion to the voltage of the supply source whereby the quiescent collector current in the transistors of the output stage is independent of fluctuations in the supply voltage.
Inventors
- 👤 J Mattfeld
- 👤 F Pieper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:51
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/307; H03F1/302; H03F3/00; H03F3/30; H03F3/3083; H03F3/3086; H03F3/3088
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
243 words
In an amplifier having a voltage supply source, a driver stage including a first transistor having an input signal applied thereto, a class-B push-pull output stage including second and third transistors having signal inputs, one of said signal inputs being coupled to the output electrode of said first transistor, means coupled between the signal inputs of said second and third transistors for maintaining the quiescent collector current of said second and third transistors independent of temperature fluctuations in said second and third transistor, and a fourth transistor, whose collector-emitter path forms a load resistance for said first transistor, connected in series with the collector-emitter path of said first transistor, the series connected collector-emitter paths of said first and fourth transistors being connected across said voltage supply source, and the other of said signal inputs of said second and third transistors being coupled to the electrode of the collectoremitter path of said forwith transistor which is connected to said output electrode of said first transistor, the improvement comprising a constant current source means, connected across said voltage supply source for supplying a constant current to the base electrode of said fourth transistor to control same so that the collector-emitter voltage of said fourth transistor and hence said load resistance of said first transistor varies substantially in proportion to the voltage of said voltage supply source, whereby the quiescent collector current in said second and third transistors is independent of fluctuations in the supply voltage.
Claim 2
Dependent Claim
243 words
In an amplifier having a voltage supply source, a driver stage including a first transistor having an input signal applied thereto, a class-B push-pull output stage including second and third transistors having signal inputs, one of said signal inputs being coupled to the output electrode of said first transistor, means coupled between the signal inputs of said second and third transistors for maintaining the quiescent collector current of said second and third transistors independent of temperature fluctuations in said second and third transistor, and a fourth transistor, whose collector-emitter path forms a load resistance for said first transistor, connected in series with the collector-emitter path of said first transistor, the series connected collector-emitter paths of said first and fourth transistors being connected across said voltage supply source, and the other of said signal inputs of said second and third transistors being coupled to the electrode of the collectoremitter path of said forwith transistor which is connected to said output electrode of said first transistor, the improvement comprising a constant current source means, connected across said voltage supply source for supplying a constant current to the base electrode of said fourth transistor to control same so that the collector-emitter voltage of said fourth transistor and hence said load resistance of said first transistor varies substantially in proportion to the voltage of said voltage supply source, whereby the quiescent collector current in said second and third transistors is independent of fluctuations in the supply voltage.
Claim 3
Dependent Claim
58 words
An amplifier as defined in claim 1, wherein said second and third transistors are comprised of transistors having the same sequence of regions, and wherein said class-B push-pull stage further comprises a fifth transistor preceding one of said second and third transistors and complementary to said one of said second and third transistors for providing a phase reversal.
Claim 4
Dependent Claim
25 words
An amplifier as defined in claim 2, wherein said second and third transistors comprise n-p-n transistors, and said fifth transistor comprises a p-n-p lateral transistor.
Claim 5
Dependent Claim
31 words
An amplifier as defined in claim 3, wherein sixth and seventh transistors having common-emitter connections are connected respectively between said first transistor and said second and third transistors for current amplification.
Claim 6
Dependent Claim
52 words
An amplifier as defined in claim 4, wherein said means for maintaining said quiescent collector current in said second and third transistors comprises a plurality of diodes connected in the forward direction in parallel to the series-connection of the base-emitter paths of said sixth transistor, said second transistor and said fifth transistor.
Claim 7
Dependent Claim
35 words
An amplifier as defined in claim 3, wherein said fourth transistor comprises a p-n-p transistor, the emitter electrode of which is connected, through a load resistance L, to the positive pole of said voltage source.
Claim 8
Dependent Claim
39 words
An amplifier as defined in claim 6, wherein said fourth transistor comprises a lateral transistor and wherein said amplifier further comprises a further transistor with a common-emitter connection and complementary to and following said fourth transistor for current amplification.
Claim 9
Dependent Claim
101 words
An amplifier as defined in claim 1, wherein said constant-current source means comprises a transistor which is operated with a common-emitter connection, the collector electrode for said constant current source transistor being connected to the base electrode of the said fourth transistor, and a voltage divider, including the series connection of a resistor and at least one diode loaded in the forward direction, connected across said voltage supply source and having its output connected to the base electrode of said constant current source transistor for determining the base bias of said constant current source transistor by providing a constant voltage drop.
Claim 10
Dependent Claim
24 words
An amplifier as defined in claim 1, wherein at least said class-B push-pull output stage comprises an integrated unit in a common semiconductor body.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |