US5070305A
Expired / Lapsed
US
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Device for converting unbalanced analog electric signals into fully differential signals
Assignee: STMicroelectronics SRL
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Filing: 1990-07-31
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Granted: 1991-12-03
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Expires: 2010-07-31
Abstract
Abstract An all-differential operational amplifier (20) has a first input (22) and a second input (24) and correspondingly has a first output (26) and a second output (28), fed back on its own input respectively through a first (34) and second (36) impedance which are generally resistive and have identical values. The first output is connected to the second input of the operational amplifier across a third impedance (32). A fourth impedance (30), equal in value to the third impedance, is connected in series to the first input and acts as input terminal of the converter. The resistive components of the impedance can be implemented as switched capacitors.
Inventors
- 👤 Pierangelo Confalonieri
- 👤 Germano Nicollini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:27
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/005; H03F1/00; H03F1/30; H03F1/303; H03F3/26
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
92 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output being connected to said second input of said operational amplifier through a third impedance, while a fourth impedance, equal in value to said third impedance, being connected in series to said first input.
Claim 2
Dependent Claim
92 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output being connected to said second input of said operational amplifier through a third impedance, while a fourth impedance, equal in value to said third impedance, being connected in series to said first input.
Claim 3
Dependent Claim
11 words
Converter according to claim 1, wherein said impedances are substantially resistive.
Claim 4
Dependent Claim
31 words
Converter according to claim 2, wherein said resistance value of said third and fourth impedances is greater than half of the value of said resistance of said first and second impedances.
Claim 5
Dependent Claim
33 words
Converter according to claim 2, characterized in that the resistance value of said third and fourth impedances is equal to 1.5 times the value of the resistance of said first and second impedances.
Claim 6
Dependent Claim
40 words
Converter according to claim 1, wherein each of said first and second impedances is constituted by a switched capacitor arranged in parallel to a fixed capacitor, and each of said third and fourth impedances is constituted by a switched capacitor.
Claim 7
Dependent Claim
38 words
Converter according to claim 5, wherein the equivalent resistive component of said third and fourth impedances has a value which is greater than half of the value of the equivalent resistive component of said first and second impedances.
Claim 8
Dependent Claim
23 words
A device according to claim 6, wherein said switched capacitors of said first and second impedances are connectable to a reference ground line.
Claim 9
Dependent Claim
23 words
A device according to claim 5, wherein said switched capacitors of said first and second impedances are connectable to a reference ground line.
Claim 10
Independent Claim
115 words
A device for converting unbalanced analog electric signals into fully-differential, balanced signals, comprising: a fully differential operational amplifier having a first input, a second input, a first output and a second output; a first impedance connected from said first output to said first input; a second impedance connected from said second output to said second input; a third impedance connected from said first output to said second input; means for receiving the unbalanced analog electric signal; a fourth impedance connected from said means for receiving the unbalanced analog electric signal to said first input; and said first impedance being substantially equal to said second impedance and said third impedance substantially equal to said fourth impedance.
Claim 11
Independent Claim
115 words
A device for converting unbalanced analog electric signals into fully-differential, balanced signals, comprising: a fully differential operational amplifier having a first input, a second input, a first output and a second output; a first impedance connected from said first output to said first input; a second impedance connected from said second output to said second input; a third impedance connected from said first output to said second input; means for receiving the unbalanced analog electric signal; a fourth impedance connected from said means for receiving the unbalanced analog electric signal to said first input; and said first impedance being substantially equal to said second impedance and said third impedance substantially equal to said fourth impedance.
Claim 12
Dependent Claim
12 words
A device according to claim 9, wherein said impedances are substantially resistive.
Claim 13
Dependent Claim
32 words
A device according to claim 10, wherein said resistance value of said third and fourth impedances is greater than half of the value of said resistance of said first and second impedances.
Claim 14
Dependent Claim
34 words
A device according to claim 10, characterized in that the resistance value of said third and fourth impedances is equal to 1.5 times the value of the resistance of said first and second impedances.
Claim 15
Dependent Claim
37 words
A device according to claim 9, wherein each of said first and second impedances comprises a switched capacitor arranged in parallel to a fixed capacitor, and each of said third and fourth impedances comprises a switched capacitor.
Claim 16
Dependent Claim
39 words
A device according to claim 13, wherein the equivalent resistive component of said third and fourth impedances has a value which is greater than half of the value of the equivalent resistive component of said first and second impedances.
Claim 17
Dependent Claim
24 words
A converter according to claim 14, wherein said switched capacitors of said first and said second impedances are connectable to a reference ground line.
Claim 18
Dependent Claim
24 words
A converter according to claim 13, wherein said switched capacitors of said first and said second impedances are connectable to a reference ground line.
Claim 19
Dependent Claim
125 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, and a fourth impedance, equal in value to said third impedance, being connected in series to said first input, wherein said impedances are substantially resistive, and further wherein the resistance value of said third and fourth impedances is greater than half of the value of said resistance of said first and second impedances.
Claim 20
Dependent Claim
125 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, and a fourth impedance, equal in value to said third impedance, being connected in series to said first input, wherein said impedances are substantially resistive, and further wherein the resistance value of said third and fourth impedances is greater than half of the value of said resistance of said first and second impedances.
Claim 21
Dependent Claim
116 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, and a fourth impedance, equal in value to said third impedance, connected in series to said first input, wherein the resistance value of said third and fourth impedances is equal to 1.5 times the value of the resistance of said first and second impedances.
Claim 22
Dependent Claim
116 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, and a fourth impedance, equal in value to said third impedance, connected in series to said first input, wherein the resistance value of said third and fourth impedances is equal to 1.5 times the value of the resistance of said first and second impedances.
Claim 23
Dependent Claim
159 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, while a fourth impedance, equal in value to said third impedance, connected in series to said first input, wherein each of said first and second impedances is constituted by a switched capacitor arranged in parallel to a fixed capacitor, and each of said third and fourth impedances is constituted by a switched capacitor, and wherein the equivalent resistive component of said third and fourth impedances has a value which is greater than half of the value of the equivalent resistive component of said first and second impedances.
Claim 24
Dependent Claim
159 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, while a fourth impedance, equal in value to said third impedance, connected in series to said first input, wherein each of said first and second impedances is constituted by a switched capacitor arranged in parallel to a fixed capacitor, and each of said third and fourth impedances is constituted by a switched capacitor, and wherein the equivalent resistive component of said third and fourth impedances has a value which is greater than half of the value of the equivalent resistive component of said first and second impedances.
Claim 25
Dependent Claim
122 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, and a fourth impedance, equal in value to said third impedance, being connected in series to said first input, a pair of output terminals, and means coupling the respective first and second outputs of said operational amplifier to said output terminals to provide a corresponding plurality of output voltage signals.
Claim 26
Dependent Claim
122 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, and a fourth impedance, equal in value to said third impedance, being connected in series to said first input, a pair of output terminals, and means coupling the respective first and second outputs of said operational amplifier to said output terminals to provide a corresponding plurality of output voltage signals.
Claim 27
Dependent Claim
117 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, and a fourth impedance, equal in value to said third impedance, being connected in series to said first input, means for receiving the unbalanced analog electric signal, and means for coupling said unbalanced analog electric signal to only said first input of said operational amplifier.
Claim 28
Dependent Claim
117 words
Device for converting unbalanced analog electric signals into fully-differential balanced signals, comprising a fully-differential operational amplifier having a first input and a second input and correspondingly a first output and a second output, each of said outputs being fed back to said corresponding input respectively through a first impedance and a second impedance of identical value, said first output connected to said second input of said operational amplifier through a third impedance, and a fourth impedance, equal in value to said third impedance, being connected in series to said first input, means for receiving the unbalanced analog electric signal, and means for coupling said unbalanced analog electric signal to only said first input of said operational amplifier.
References Cited (Backward Citations)
US4723112A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |