US4425550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Charge pump amplifier
Assignee: Motorola Solutions Inc
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Filing: 1981-12-24
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Granted: 1984-01-10
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Expires: 2001-12-24
Abstract
Abstract A charge pump amplifier useful for providing precise gain in integrated circuits is described. The amplifier uses an operational amplifier with a capacitive feedback to accumulate successive charges applied to the input of the operational amplifier by a switched-capacitor input. If the capacitors are of equal size, the gain of the amplifier is a function of the ratio of the frequency of the switched capacitor input and the frequency of discharge of the feedback capacitor.
Inventors
- 👤 Michael D. Smith
- 👤 James A. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:35
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
130 words
A charge pump amplifier comprising: an operational amplifier having an input and an output; feedback means connected between the input and the output of the operational amplifier and comprising a storage means; means selectively coupled to the input of the operational amplifier and to a voltage source, for storing a charge from the voltage source, and for transferring the stored charge to the input of the operational amplifier; means for selectively discharging the storage means at a rate different than the rate at which the stored charges are applied to input of the operational amplifier; whereby a plurality of charges from the means for storing a charge are transferred to the storage means, and the plurality of the charges are accumulated by the storage means prior to the discharge thereof.
Claim 2
Dependent Claim
130 words
A charge pump amplifier comprising: an operational amplifier having an input and an output; feedback means connected between the input and the output of the operational amplifier and comprising a storage means; means selectively coupled to the input of the operational amplifier and to a voltage source, for storing a charge from the voltage source, and for transferring the stored charge to the input of the operational amplifier; means for selectively discharging the storage means at a rate different than the rate at which the stored charges are applied to input of the operational amplifier; whereby a plurality of charges from the means for storing a charge are transferred to the storage means, and the plurality of the charges are accumulated by the storage means prior to the discharge thereof.
Claim 3
Dependent Claim
30 words
A charge pump amplifier as set forth in claim 1 wherein the means for storing a charge and for transferring the stored charge comprises a capacitor coupled to a switch.
Claim 4
Dependent Claim
20 words
A charge pump amplifier as set forth in claims 1 or 2 wherein the feedback means comprises a feedback capacitor.
Claim 5
Dependent Claim
32 words
A charge pump amplifier as set forth in claim 3 further comprising a switch, the switch being coupled in parallel to the feedback capacitor, and selectively operable to discharge the feedback capacitor.
Claim 6
Dependent Claim
58 words
A charge pump amplifier as set forth in claim 4 wherein the capacitor and the feedback capacitor are of equal size, whereby the voltage at the output of the operational amplifier is a function of the voltage at the voltage source and the number of charges transferred to the feedback capacitor before the feedback capacitor is selectively discharged.
References Cited (Backward Citations)
US4329599A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |