← Back to Patent Explorer
US4555670A Expired / Lapsed US ⏱️ 0.0 years remaining

Differential amplifier

Assignee: Toshiba Corp
•
Filing: 1984-11-08
•
Granted: 1985-11-26
•
Expires: 2004-11-08
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A differential amplifier is disclosed which comprises: a first differential amplifying circuit comprising first and second transistors of an NPN type, the collector of the first transistor constituting an output terminal of the amplifier; a second differential amplifying circuit comprising third and fourth transistors of the NPN type whose bases are inverting and noninverting input terminals, respectively, the base of the third transistor being connected to the collector of the second transistor, and the base of the fourth transistor being supplied with a bias voltage; a first load circuit for the first differential amplifying circuit, the first load circuit comprising a fifth transistor of a PNP type forming a collector load for the second transistor and a sixth transistor of the PNP type for forming a collector load for the first transistor, the bases of the fifth and sixth transistors being connected to the collector of the fourth transistor; and a second load circuit for the second differential amplifying circuit.

Inventors

  • 👤 Tatsuo Tanaka

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 17:55
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/24; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/4508; H03F3/45085; H03F3/45479; H03F3/45484; H03F3/45596; H03F3/456; H03F2203/00; H03F2203/45; H03F2203/45641; H03F2203/45648; H03F2203/45674; H03F2203/45696

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 188 words
A differential amplifier comprising: first and second input terminals; an output terminal; a first differential amplifying circuit comprising first and second transistors of a first polarity type, the bases of the first and second transistors being connected to said first and second input terminals, respectively; a current source connected to said first differential amplifying circuit and a first predetermined potential; a second differential amplifying circuit comprising third and fourth transistors of said first polarity type, the base of the third transistor constituting an inverting input terminal and being connected to the collector of said second transistor, and the base of the fourth transistor constituting a noninverting input terminal and being connected to a bias potential; a load circuit for said second differential amplifying circuit; a fifth transistor of a second polarity type forming a collector load for said second transistor, the base of the fifth transistor being connected to the collector of said fourth transistor; and a sixth transistor of said second polarity type for forming a collector load for said first transistor, the base of the sixth transistor being connected to the base of said fifth transistor.
Claim 2
Dependent Claim 188 words
A differential amplifier comprising: first and second input terminals; an output terminal; a first differential amplifying circuit comprising first and second transistors of a first polarity type, the bases of the first and second transistors being connected to said first and second input terminals, respectively; a current source connected to said first differential amplifying circuit and a first predetermined potential; a second differential amplifying circuit comprising third and fourth transistors of said first polarity type, the base of the third transistor constituting an inverting input terminal and being connected to the collector of said second transistor, and the base of the fourth transistor constituting a noninverting input terminal and being connected to a bias potential; a load circuit for said second differential amplifying circuit; a fifth transistor of a second polarity type forming a collector load for said second transistor, the base of the fifth transistor being connected to the collector of said fourth transistor; and a sixth transistor of said second polarity type for forming a collector load for said first transistor, the base of the sixth transistor being connected to the base of said fifth transistor.
Claim 3
Dependent Claim 71 words
A differential amplifier according to claim 1, wherein said load circuit comprises seventh and eighth transistors, the seventh transistor being inserted between the collector of said third transistor and a second predetermined potential and having the collector and base connected together, and the eighth transistor being connected between the collector of said fourth transistor and said second predetermined potential and having the base connected to the base of the seventh transistor.
Claim 4
Dependent Claim 58 words
A differential amplifier according to claim 1, wherein said load circuit comprises a seventh transistor of said second polarity type connected between the collector of said fourth transistor and a second predetermined potential, the collector and base of the seventh transistor being connected together, and the collector of said third transistor being connected to said second predetermined potential.
Claim 5
Dependent Claim 42 words
A differential amplifier according to claim 1, further comprising a first resistor connected between a second predetermined potential and the emitter of said fifth transistor and a second resistor connected between said second predetermined potential and the emitter of said sixth transistor.
Claim 6
Dependent Claim 42 words
A differential amplifier according to claim 2, further comprising a first resistor connected between said second predetermined potential and the emitter of said fifth transistor and a second resistor connected between said second predetermined potential and the emitter of said sixth transistor.
Claim 7
Dependent Claim 42 words
A differential amplifier according to claim 3, further comprising a first resistor connected between said second predetermined potential and the emitter of said fifth transistor and a second resistor connected between said second predetermined potential and the emitter of said sixth transistor.
Claim 8
Dependent Claim 40 words
A differential amplifier according to claim 1, further comprising a first resistor connected between the emitter of said second transistor and said current source and a second resistor connected between the emitter of said first transistor and said current source.
Claim 9
Dependent Claim 40 words
A differential amplifier according to claim 2, further comprising a first resistor connected between the emitter of said second transistor and said current source and a second resistor connected between the emitter of said first transistor and said current source.
Claim 10
Dependent Claim 40 words
A differential amplifier according to claim 3, further comprising a first resistor connected between the emitter of said second transistor and said current source and a second resistor connected between the emitter of said first transistor and said current source.

References Cited (Backward Citations)

US3440554A Cited
DE1966421A1 Cited
US3564439A Cited
DE2139560A1 Cited
SU400002A1 Cited
US4272728A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-11-25 1989-05-27 1989-11-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-11-25 1993-05-27 1993-11-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-11-25 1997-05-27 1997-11-26 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag