US4751454A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trimmable circuit layout for generating a temperature-independent reference voltage
Assignee: Siemens AG
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Filing: 1986-09-29
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Granted: 1988-06-14
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Expires: 2006-09-29
Abstract
Abstract Circuit for generating a temperature-independent reference voltage includes transistors forming current sources, and a band gap circuit having bipolar transistors and being supplied by the current sources, the ratio of the emitter currents of the bipolar transistors being adjustable. The current sources may further include a first current source and a second current source parallel with the first current source.
Inventors
- 👤 Franz Dielacher
- 👤 Jochen Reisinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:25
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/30; Y; Y10; Y10S; Y10S323/00; Y10S323/907
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
120 words
Circuit for generating a temperature-independent reference voltage, comprising transistors, having control inputs, forming current sources, a band gap circuit having two branches, and having bipolar transistors, each branch being supplied by one of said current sources; one of said branches having a common emitter connection of said bipolar transistors and two resistors in a series connection with said common emitter connection, the other branch having an emitter and a single resistor in series therewith; an operational amplifier having two inputs, each connected with a respective one of said branches, and an output connected to the control input of said current source transistors; and means including switchable current sources for adjusting the ratio of the emitter currents of said bipolar transistors.
Claim 2
Dependent Claim
120 words
Circuit for generating a temperature-independent reference voltage, comprising transistors, having control inputs, forming current sources, a band gap circuit having two branches, and having bipolar transistors, each branch being supplied by one of said current sources; one of said branches having a common emitter connection of said bipolar transistors and two resistors in a series connection with said common emitter connection, the other branch having an emitter and a single resistor in series therewith; an operational amplifier having two inputs, each connected with a respective one of said branches, and an output connected to the control input of said current source transistors; and means including switchable current sources for adjusting the ratio of the emitter currents of said bipolar transistors.
Claim 3
Dependent Claim
25 words
Circuit according to claim 1, wherein said current sources include a first current source and second switchable current sources parallel to said first current source.
Claim 4
Dependent Claim
14 words
Circuit according to claim 2, including means for individually switching said second current sources.
Claim 5
Dependent Claim
22 words
Circuit according to claim 2, including means for switching on a portion and switching off a portion of said second current sources.
Claim 6
Dependent Claim
15 words
Circuit according to claim 3, wherein said switching means are in the form of transistors.
Claim 7
Dependent Claim
15 words
Circuit according to claim 4, wherein said switching means are in the form of transistors.
Claim 8
Dependent Claim
16 words
Circuit according to claim 2, wherein said second current sources supply currents weighted in binary fashion.
Claim 9
Dependent Claim
23 words
Circuit according to claim 2, wherein said second current sources are formed of identical transistors of one conduction type being connected in parallel.
Claim 10
Dependent Claim
25 words
Circuit according to claim 2, wherein said second current sources are formed of identical transistors of one conduction type said transistors being connected in series.
Claim 11
Dependent Claim
23 words
Circuit according to claim 5, wherein said transistors of said current sources and said transistors of said switching means are metal oxide semiconductors.
Claim 12
Dependent Claim
23 words
Circuit according to claim 6, wherein said transistors of said current sources and said transistors of said switching means are metal oxide semiconductors.
Claim 13
Dependent Claim
22 words
Circuit according to claim 1, wherein said bipolar transistors of said band gap circuit have ring emitters disposed about a base contact.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-14 | 1991-12-14 | 1992-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-14 | 1995-12-14 | 1996-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-14 | 1999-12-14 | 2000-06-14 | $7700.00 | Window Closed / Lapsed |