Patent US5552744A successfully refreshed from Google Patents.
US5552744A
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US
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High speed IDDQ monitor circuit
Assignee: Xcerra Corp
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Filing: 1995-06-05
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Granted: 1996-09-03
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Expires: 2015-06-05
Abstract
Abstract A process for determining a quiescent power supply current (I DDQ ) of a device under test (DUT) at a first node. The process includes the steps of providing a reference current to the first node and decoupling a power supply from the first node. A first node voltage is determined at a first time after the power supply is decoupled from the first node. The first node voltage is determined at a second time after the first time. If the first node voltage increases from the first time to the second time, it is indicated that the I DDQ of the DUT is less than the reference current. If the first node voltage decreases from the first time to the second time, it is indicated that the I DDQ of the DUT is greater than the reference current.
Inventors
- 👤 Phillip D. Burlison
- 👤 William R. DeHaven
- 👤 Victor Pogrebinsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:33
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/28; G01R31/30; G01R31/3004; G01R31/3008; G01R31/317; G01R31/3181; G01R31/319; G01R31/3193
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
83 words
A process for reducing charge injection when decoupling a power supply from a first node, comprising the steps of: providing n switches coupled in parallel between the power supply and the first node, each of the n switches having a different resistance when closed; and sequentially opening each of the n switches, wherein a first switch having a lowest resistance is opened first and each successive switch that is opened has a greater resistance than a previous switch that has been previously opened.
Claim 2
Dependent Claim
83 words
A process for reducing charge injection when decoupling a power supply from a first node, comprising the steps of: providing n switches coupled in parallel between the power supply and the first node, each of the n switches having a different resistance when closed; and sequentially opening each of the n switches, wherein a first switch having a lowest resistance is opened first and each successive switch that is opened has a greater resistance than a previous switch that has been previously opened.
Claim 3
Dependent Claim
135 words
A process for reducing charge injection when decoupling a power supply from a first node, comprising the steps of: providing a first switch having a first resistance, the first switch being coupled between the power supply and the first node; providing a second switch having a second resistance that is greater than the first resistance, the second switch being coupled in parallel to the first switch; providing a third switch having a third resistance that is greater than the second resistance, the third switch being coupled in parallel to the first and second switches; opening the first switch; opening the second switch after the first switch is opened; and opening the third switch after the second switch is opened, wherein the power supply is decoupled from the first node when all three switches are open.
Claim 4
Dependent Claim
135 words
A process for reducing charge injection when decoupling a power supply from a first node, comprising the steps of: providing a first switch having a first resistance, the first switch being coupled between the power supply and the first node; providing a second switch having a second resistance that is greater than the first resistance, the second switch being coupled in parallel to the first switch; providing a third switch having a third resistance that is greater than the second resistance, the third switch being coupled in parallel to the first and second switches; opening the first switch; opening the second switch after the first switch is opened; and opening the third switch after the second switch is opened, wherein the power supply is decoupled from the first node when all three switches are open.
Claim 5
Dependent Claim
93 words
A switch circuit for coupling and decoupling a first node to a second node, the switch circuit having reduced charge injection, comprising: a plurality of switches coupled between the first node and the second node, each switch having a unique resistance when switched on, each switch being controlled independently, wherein a switch having a lowest resistance is switched off first and successive switches are sequentially switched off according to which switch has a next lowest resistance until all switches are switched off such that the first node is decoupled from the second node.
Claim 6
Dependent Claim
93 words
A switch circuit for coupling and decoupling a first node to a second node, the switch circuit having reduced charge injection, comprising: a plurality of switches coupled between the first node and the second node, each switch having a unique resistance when switched on, each switch being controlled independently, wherein a switch having a lowest resistance is switched off first and successive switches are sequentially switched off according to which switch has a next lowest resistance until all switches are switched off such that the first node is decoupled from the second node.
Claim 7
Dependent Claim
50 words
The switch circuit of claim 3, wherein a switch having a greatest resistance is switched on first and successive switches are sequentially switched on according to which switch has a next greatest resistance until all switches are switched on such that the first node is coupled to the second node.
Claim 8
Dependent Claim
108 words
A switch circuit for coupling and decoupling a first node to a second node, the switch circuit having reduced charge injection, comprising: a plurality of switches coupled between the first node and the second node, each switch having a unique resistance when switched on and being controlled independently, wherein a switch having a lowest resistance is switched off first and successive switches are sequentially switched off, each after a predetermined interval of time has elapsed from a previous switch being switched off, according to which switch has a next lowest resistance until all switches are switched off such that the first node is decoupled from the second node.
Claim 9
Dependent Claim
108 words
A switch circuit for coupling and decoupling a first node to a second node, the switch circuit having reduced charge injection, comprising: a plurality of switches coupled between the first node and the second node, each switch having a unique resistance when switched on and being controlled independently, wherein a switch having a lowest resistance is switched off first and successive switches are sequentially switched off, each after a predetermined interval of time has elapsed from a previous switch being switched off, according to which switch has a next lowest resistance until all switches are switched off such that the first node is decoupled from the second node.
Claim 10
Dependent Claim
65 words
The switch circuit of claim 5, wherein a switch having a greatest resistance is switched on first and successive switches are sequentially switched on, each after a predetermined interval time has elapsed from a previous switch being switched on, according to which switch has a next greatest resistance until all switches are switched on such that the first node is coupled to the second node.
Claim 11
Dependent Claim
108 words
A process for reducing charge injection when decoupling a power supply from a first node, comprising the steps of: providing n switches coupled in parallel between the power supply and the first node, each of the n switches having a different resistance when closed; and sequentially opening each of the n switches after a predetermined interval of time has elapsed from a previous switch being opened to compensate for charge injection due to opening the previous switch, wherein a first switch having a lowest resistance is opened first and each successive switch that is opened has a greater resistance than a previous switch that has been previously opened.
Claim 12
Dependent Claim
108 words
A process for reducing charge injection when decoupling a power supply from a first node, comprising the steps of: providing n switches coupled in parallel between the power supply and the first node, each of the n switches having a different resistance when closed; and sequentially opening each of the n switches after a predetermined interval of time has elapsed from a previous switch being opened to compensate for charge injection due to opening the previous switch, wherein a first switch having a lowest resistance is opened first and each successive switch that is opened has a greater resistance than a previous switch that has been previously opened.
Claim 13
Dependent Claim
108 words
A process for reducing charge injection when coupling a power supply to a first node, comprising the steps of: providing n switches coupled in parallel between the power supply and the first node, each of the n switches having a different resistance when closed; and sequentially closing each of the n switches after a predetermined interval of time has elapsed from a previous switch being closed to compensate for charge injection due to closing the previous switch, wherein a first switch having a highest resistance is closed first and each successive switch that is closed has a lower resistance than a previous switch that has been previously closed.
Claim 14
Dependent Claim
108 words
A process for reducing charge injection when coupling a power supply to a first node, comprising the steps of: providing n switches coupled in parallel between the power supply and the first node, each of the n switches having a different resistance when closed; and sequentially closing each of the n switches after a predetermined interval of time has elapsed from a previous switch being closed to compensate for charge injection due to closing the previous switch, wherein a first switch having a highest resistance is closed first and each successive switch that is closed has a lower resistance than a previous switch that has been previously closed.
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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) | 1999-09-03 | 2000-03-04 | 2000-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-03 | 2004-03-04 | 2004-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-03 | 2008-03-04 | 2008-09-03 | $7700.00 | Window Closed / Lapsed |