US4723110A
Expired / Lapsed
US
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Transconductance amplifier
Assignee: US Philips Corp
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Filing: 1987-02-17
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Granted: 1988-02-02
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Expires: 2007-02-17
Abstract
Abstract A transconductance amplifier comprising a voltage divider including two identical resistors (R o ) connected between the bases (3, 4) of two first transistors (T o1 , T o2 ) arranged as a differential pair, each having a first emitter area (e o ). The junction point of said resistors (R o ) is connected to the base of a second transistor (T 1 ) having a second emitter area (2e 1 ), whose emitter, like that of the first transistors (T o1 , T o2 ), is connected to a current source (6). For a ratio between the second and the first emitter areas (2e 1 ; e o ) equal to 4:1 the difference between the output currents (I 1 , I 3 ) of the first transistors (T o1 , T o2 ) increases as a linear function of the input voltage over a range which is as large as possible.
Inventors
- 👤 Johannes O. Voorman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:08
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/56; H03F1/32; H03F1/3211; H03F3/00; H03F3/45; H03F3/45071
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
170 words
A transconductance amplifier comprising two transistors T o each having an emitter area e o , and bases constituting inputs for receiving an input voltage and emitters connected to a current source, and at least a first output for an output current, characterized in that a series arrangement of 2N+1 impedances R o , . . . , R N-1 , R N , R N-1 , . . . , R o having resistance values W k , where k=0, . . . , N, is coupled between the bases of the two transistors, and 2N junction points a 1 , . . . , a N , a N , . . . , a 1 between the 2N+1 resistors are connected to the bases of 2N transistors, T 1 , . . . , T N , T N , . . . , T 1 having emitter areas e k , where k=1, . . . , N, where N is an integer such that N≧1.
Claim 2
Dependent Claim
170 words
A transconductance amplifier comprising two transistors T o each having an emitter area e o , and bases constituting inputs for receiving an input voltage and emitters connected to a current source, and at least a first output for an output current, characterized in that a series arrangement of 2N+1 impedances R o , . . . , R N-1 , R N , R N-1 , . . . , R o having resistance values W k , where k=0, . . . , N, is coupled between the bases of the two transistors, and 2N junction points a 1 , . . . , a N , a N , . . . , a 1 between the 2N+1 resistors are connected to the bases of 2N transistors, T 1 , . . . , T N , T N , . . . , T 1 having emitter areas e k , where k=1, . . . , N, where N is an integer such that N≧1.
Claim 3
Dependent Claim
56 words
A transconductance amplifier as claimed in claim 1, characterized in that collectors of the transistors T 1 , . . . , T N , T N , . . . , T 1 are connected to a power-supply terminal and in that collectors of the transistors T o constitute the outputs of the transconductance amplifier.
Claim 4
Dependent Claim
39 words
A transconductance amplifier as claimed in claim 2, characterized in that for a resistance value W N of the resistor R N equal to zero the two junction points a N form a single junction point a N .
Claim 5
Dependent Claim
87 words
A transconductance amplifier as claimed in claim 1, characterized in that each of the transistors T 1 , . . . , T N , T N , . . . , T 1 comprise two parallel-connected transistors, the collector of one transistor being connected to the one transistor T o and the collector of the other transistor being connected to the other transistor T o , and in that the collector of one of the transistors T o constitutes a first output of the transconductance amplifier.
Claim 6
Dependent Claim
27 words
A transconductance amplifier as claimed in claim 4, characterized in that the collector of the other transistor T o constitutes a second output of the transconductance amplifier.
Claim 7
Dependent Claim
52 words
A transconductance amplifier as claimed in claim 4, characterized in that for a resistance value W N of the resistor R N equal to zero the two junction points a N form a single junction point and in that the two transistors T N are parallel connected to form a compound transistor.
Claim 8
Dependent Claim
45 words
A transconductance amplifier as claimed in claim 1, characterized in that the collectors of the transistors T 1 , . . . , T N , T N , . . . , T 1 are connected to a first output of the transconductance amplifier.
Claim 9
Dependent Claim
28 words
A transconductance amplifier as claimed in claim 7, characterized in that the collectors of the transistors T o are connected to a second output of the transconductance amplifier.
Claim 10
Dependent Claim
39 words
A transconductance amplifier as claimed in claim 7, characterized in that for a resistance value W N of the resistor R N equal to zero the two junction points a N form a single junction point a N .
Claim 11
Dependent Claim
36 words
A transconductance amplifier as claimed in claim 3, characterized in that for N=1 the ratio between the emitter areas of the transistors T 1 and T o is substantially equal to e 1 :e o =2:1.
Claim 12
Dependent Claim
65 words
A transconductance amplifier as claimed in claim 3, characterized in that for N=2 the ratio between the emitter areas of the transistors T 2 , T 1 and T o is substantially equal to e 2 :e 1 :e o =32:49:9 and the ratio between the resistance values of the resistors R 1 and R o is substantially equal to W 1 :W o =1.9:1.
Claim 13
Dependent Claim
75 words
A transconductance amplifier as claimed in claim 3, characterized in that for N=3 the ratio between the emitter areas of the transistors T 3 , T 2 , T 1 and T o is substantially equal to e 3 :e 2 :e 1 e o =5:9:6:1 and the ratio between the resistance values of the resistors R 2 , R 1 and R o is substantially equal to W 2 :W 1 :W o =47:36:17.
Claim 14
Dependent Claim
60 words
A transconductance amplifier as claimed in claim 2, characterized in that for N=1 the ratio between the emitter areas of the transistors T 1 and T o is substantially equal to e 1 :e o =5:1 and the ratio between the resistance values of the resistors R 1 and R o is substantially equal to W 1 :W o =8:5.
Claim 15
Dependent Claim
70 words
A transconductance amplifier as claimed in claim 2, characterized in that for N=2 the ratio between the emitter areas of the transistors T 2 , T 1 and T o is substantially equal to e 2 :e 1 :e o =25:17:3 and the ratio between the resistance values of the resistors R 2 , R 1 and R o is substantially equal to W 2 :W 1 :W o =2.4:2:1.
Claim 16
Dependent Claim
36 words
A transconductance amplifier as claimed in claim 9, characterized in that for N=1 the ratio between the emitter areas of the transistors T 1 and T o is substantially equal to e o :e 1 =5:1.
Claim 17
Dependent Claim
48 words
A transconductance amplifier as claimed in claim 5 wherein for a resistance value W N of the resistor R N equal to zero the two junction points a N form a single junction point and the two transistors T N are parallel connected to form a compound transistor.
Claim 18
Dependent Claim
37 words
A transconductance amplifier as claimed in claim 8 wherein for a resistance value W N of the resistor R N equal to zero the two junction points a N form a single junction point a N .
Claim 19
Dependent Claim
34 words
A transconductance amplifier as claimed in claim 6 wherein for N=1 the ratio between the emitter areas of the transistors T 1 and T 0 is substantially equal to e 1 :e 0 =2:1.
Claim 20
Dependent Claim
63 words
A transconductance amplifier as claimed in claim 6 wherein for N=2 the ratio between the emitter areas of the transistors T 2 , T 1 and T 0 is substantially equal to e 2 :e 1 :e 0 =32:49:9 and the ratio between the resistance values of the resistors R 1 and R 0 is substantially equal to W 1 :W 0 =1.9:1.
Claim 21
Dependent Claim
74 words
A transconductance amplifier as claimed in claim 6 wherein for N=3 the ratio between the emitter areas of the transistors T 3 , T 2 , T 1 and T 0 is substantially equal to e 3 :e 2 :e 1 :e 0 =5:9:6:1 and the ratio between the resistance values of the resistors R 2 , R 1 , and R 0 is substantially equal to W 2 :W 1 :W 0 =47:36:17.
References Cited (Backward Citations)
US4612513A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-01 | 1991-08-03 | 1992-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-01 | 1995-08-03 | 1996-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-01 | 1999-08-03 | 2000-02-02 | $7700.00 | Window Closed / Lapsed |