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US4890052A
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Temperature constant current reference
Assignee: Texas Instruments Inc
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Filing: 1988-08-04
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Granted: 1989-12-26
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Expires: 2008-08-04
Abstract
Abstract A temperature constant Gm current reference circuit which is also independent of voltage across the circuit which includes a circuit for applying a substantially identical voltage to a semiconductor diode as well as to a branch circuit comprising a polysilicon resistor of predetermined doping level in series with plural unidirectional current carrying devices connected in parallel, preferably in the form of a multi-electrode transistor. From eight to twelve such unidirectional current carrying devices are required in the preferred embodiment.
Inventors
- 👤 James R. Hellums
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:29
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; Y; Y10; Y10S; Y10S323/00; Y10S323/907
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
88 words
A temperature constant Gm current reference circuit comprising: (a) a unidirectionally conducting semiconductor device coupled to a reference voltage source; (b) a branch circuit comprising a polysilicon resistor having a negative temperature coefficient of resistance and having a predetermined doping level and a plurality of parallel connected unidirectional current carrying elements serially connected to said resistor, said branch circuit being coupled at one end thereof to said reference voltage source; and (c) means to apply a substantially identical voltage across each said semiconductor device and said branch circuit.
Claim 2
Dependent Claim
88 words
A temperature constant Gm current reference circuit comprising: (a) a unidirectionally conducting semiconductor device coupled to a reference voltage source; (b) a branch circuit comprising a polysilicon resistor having a negative temperature coefficient of resistance and having a predetermined doping level and a plurality of parallel connected unidirectional current carrying elements serially connected to said resistor, said branch circuit being coupled at one end thereof to said reference voltage source; and (c) means to apply a substantially identical voltage across each said semiconductor device and said branch circuit.
Claim 3
Dependent Claim
86 words
A temperature constant Gm current reference circuit as set forth in claim 1 wherein said means to apply substantially identical voltage comprises a pair of p-channel transistors, each said transistor being coupled to a source of voltage and a pair of n-channel transistors coupled between said p-channel transistors and said semiconductor device and branch circuit to form a pair of parallel circuits, each said parallel circuit containing one of said p-channel and one of said n-channel transistors and one of said semiconductor device and branch circuit.
Claim 4
Dependent Claim
28 words
A temperature constant Gm current reference circuit as set forth in claim 2 wherein said plurality of parallel connected unidirectional current carrying devices is from 8 to 12.
Claim 5
Dependent Claim
32 words
A temperature constant Gm current reference circuit as set forth in claim 2 further including start-up circuit means to initiate current flow in said reference circuit responsive to a predetermined voltage thereacross.
Claim 6
Dependent Claim
28 words
A temperature constant Gm current reference circuit as set forth in claim 4 wherein said plurality of parallel connected unidirectional current carrying devices is from 8 to 12.
Claim 7
Dependent Claim
32 words
A temperature constant Gm current reference circuit as set forth in claim 1 further including start-up circuit means to initiate current flow in said reference circuit responsive to a predetermined voltage thereacross.
Claim 8
Dependent Claim
28 words
A temperature constant Gm current reference circuit as set forth in claim 6 wherein said plurality of parallel connected unidirectional current carrying devices is from 8 to 12.
Claim 9
Dependent Claim
28 words
A temperature constant Gm current reference circuit as set forth in claim 1 wherein said plurality of parallel connected unidirectional current carrying devices is from 8 to 12.
Claim 10
Dependent Claim
162 words
A temperature constant Gm current reference circuit comprising: a unidirectional conducting semiconductor device coupled to a reference voltage source; a branch circuit comprising a polysilicon resistor having a negative temperature coefficient of resistance and having a predetermined doping level and a plurality of parallel connected unidirectional current carrying elements serially connected to said resistor, said branch circuit being coupled at one end thereof to said reference voltage source; a first pair of p-channel transistors, each of said first pair of p-channel transistors being coupled to a source of voltage; a second pair of p-channel transistors, each of said second pair of p-channel transistors being coupled to a different one of said first pair of p-channel transistors; and a first pair of n-channel transistors coupled to a different one of said second pair of p-channel transistors, each said second n-channel transistor being coupled between a different one of said first n-channel transistors and a different one of said semiconductor device and branch circuit.
Claim 11
Dependent Claim
162 words
A temperature constant Gm current reference circuit comprising: a unidirectional conducting semiconductor device coupled to a reference voltage source; a branch circuit comprising a polysilicon resistor having a negative temperature coefficient of resistance and having a predetermined doping level and a plurality of parallel connected unidirectional current carrying elements serially connected to said resistor, said branch circuit being coupled at one end thereof to said reference voltage source; a first pair of p-channel transistors, each of said first pair of p-channel transistors being coupled to a source of voltage; a second pair of p-channel transistors, each of said second pair of p-channel transistors being coupled to a different one of said first pair of p-channel transistors; and a first pair of n-channel transistors coupled to a different one of said second pair of p-channel transistors, each said second n-channel transistor being coupled between a different one of said first n-channel transistors and a different one of said semiconductor device and branch circuit.
Claim 12
Dependent Claim
28 words
A temperature constant Gm current reference circuit as set forth in claim 9 wherein said plurality of parallel connected unidirectional current carrying devices is from 8 to 12.
Claim 13
Dependent Claim
28 words
A temperature constant Gm current reference circuit as set forth in claim 9 wherein said plurality of parallel connected unidirectional current carrying devices is from 8 to 12.
Claim 14
Dependent Claim
186 words
A temperature constant Gm current reference circuit comprising: a unidirectional conducting semiconductor device coupled to a reference voltage source; a branch circuit comprising a polysilicon resistor having a negative temperature coefficient of resistance and having a predetermined doping level and a plurality of parallel connected unidirectional current carrying elements serially connected to said resistor, said branch circuit being coupled at one end thereof to said reference voltage source; a first pair of p-channel transistors, each of said first pair of p-channel transistors being coupled to a source of voltage; a second pair of p-channel transistors, each of said second pair of p-channel transistors being coupled to a different one of said first pair of p-channel transistors; a first pair of n-channel transistors coupled to a different one of said second pair of p-channel transistors and a second pair of n-channel transistors, each said second n-channel transistor being coupled between a different one of said first n-channel transistors and a different one of said semiconductor device and branch circuit; and startup circuit means to initiate current flow in said reference circuit responsive to a predetermined voltage thereacross.
Claim 15
Dependent Claim
186 words
A temperature constant Gm current reference circuit comprising: a unidirectional conducting semiconductor device coupled to a reference voltage source; a branch circuit comprising a polysilicon resistor having a negative temperature coefficient of resistance and having a predetermined doping level and a plurality of parallel connected unidirectional current carrying elements serially connected to said resistor, said branch circuit being coupled at one end thereof to said reference voltage source; a first pair of p-channel transistors, each of said first pair of p-channel transistors being coupled to a source of voltage; a second pair of p-channel transistors, each of said second pair of p-channel transistors being coupled to a different one of said first pair of p-channel transistors; a first pair of n-channel transistors coupled to a different one of said second pair of p-channel transistors and a second pair of n-channel transistors, each said second n-channel transistor being coupled between a different one of said first n-channel transistors and a different one of said semiconductor device and branch circuit; and startup circuit means to initiate current flow in said reference circuit responsive to a predetermined voltage thereacross.
Claim 16
Dependent Claim
28 words
A temperature constant Gm current reference circuit as set forth in claim 12 wherein said plurality of parallel connected unidirectional current carrying devices is from 8 to 12.
Claim 17
Dependent Claim
27 words
A temperature constant Gm current reference circuit as set forth in claim 12 said plurality of parallel connected unidirectional current carrying devices is from 8 to 12.
References Cited (Backward Citations)
US4029974A
Cited
US4350904A
Cited
US4733162A
Cited
US4677368A
Cited
US4792750A
Cited
US4769589A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |