US5164613A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reset monitor
Assignee: Maxim Integrated Products Inc
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Filing: 1991-07-16
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Granted: 1992-11-17
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Expires: 2011-07-16
Abstract
Abstract Reset monitor for detection of power failure and external reset for devices such as microprocessors with the reset monitor providing a single settling time hold down of a reset signal. Preferred embodiments include bandgap reference with high current side compensating resistor, bond out options for analog parameter selection, glitch free state machine control of both detections, and external pushbutton debouncing both depression and release.
Inventors
- 👤 Eric W. Mumper
- 👤 Francis A. Scherpenberg
- 👤 II William L. Payne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:24
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/22; G; G06; G06F; G06F1/00; G06F1/24; G06F1/26; G06F1/30
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
187 words
An integrated circuit, comprising: (a) a power supply terminal; (b) a second terminal; (c) a reference supply terminal; (d) a first detector for detecting a change of magnitude of the voltage of said power supply terminal relative to said reference supply terminal from greater than to less than a first predetermined voltage; (e) a second detector for detecting a change of the magnitude of the voltage of said second terminal relative to said reference supply terminal from greater than to less than a second predetermined voltage; and (f) control circuitry that (i) connects said second terminal to said reference supply terminal when said first detector detects said change of the voltage of said power supply terminal relative to said reference supply terminal to less than said first predetermined voltage and maintains said connect for a first predetermined time period, and that (ii) connects said second terminal to said reference supply terminal when said second detector detects said change of voltage of said second terminal relative to said reference supply terminal to less than said second predetermined voltage and maintains said connect for a second predetermined time period.
Claim 2
Dependent Claim
187 words
An integrated circuit, comprising: (a) a power supply terminal; (b) a second terminal; (c) a reference supply terminal; (d) a first detector for detecting a change of magnitude of the voltage of said power supply terminal relative to said reference supply terminal from greater than to less than a first predetermined voltage; (e) a second detector for detecting a change of the magnitude of the voltage of said second terminal relative to said reference supply terminal from greater than to less than a second predetermined voltage; and (f) control circuitry that (i) connects said second terminal to said reference supply terminal when said first detector detects said change of the voltage of said power supply terminal relative to said reference supply terminal to less than said first predetermined voltage and maintains said connect for a first predetermined time period, and that (ii) connects said second terminal to said reference supply terminal when said second detector detects said change of voltage of said second terminal relative to said reference supply terminal to less than said second predetermined voltage and maintains said connect for a second predetermined time period.
Claim 3
Dependent Claim
16 words
The integrated circuit of claim 1, wherein: (a) said reference supply terminal is connected to ground.
Claim 4
Dependent Claim
27 words
The integrated circuit of claim 1, wherein: (a) said first predetermined time period and said second predetermined time period are both generated by a time period generator.
Claim 5
Dependent Claim
18 words
The integrated circuit of claim 3, wherein: (a) said time period generator includes an oscillator and a counter.
Claim 6
Dependent Claim
96 words
An integrated circuit, comprising; (a) a power supply voltage detector; (b) a reset terminal voltage detector connected to a reset terminal; (c) a time period generator; and (d) control circuitry connected to said detectors and that outputs a reset signal at said reset terminal for a time period determined by said generator when either (i) said power supply voltage detector detects a power supply voltage magnitude falling below a first predetermined level or (ii) said reset terminal voltage detector detects a voltage magnitude at said reset terminal indicating an external reset signal at said reset terminal.
Claim 7
Dependent Claim
96 words
An integrated circuit, comprising; (a) a power supply voltage detector; (b) a reset terminal voltage detector connected to a reset terminal; (c) a time period generator; and (d) control circuitry connected to said detectors and that outputs a reset signal at said reset terminal for a time period determined by said generator when either (i) said power supply voltage detector detects a power supply voltage magnitude falling below a first predetermined level or (ii) said reset terminal voltage detector detects a voltage magnitude at said reset terminal indicating an external reset signal at said reset terminal.
Claim 8
Independent Claim
72 words
A method of controlling a reset terminal, comprising the steps of: (a) detecting when either (1) a power supply voltage magnitude becomes less than a first voltage or (2) a reset terminal voltage indicates a reset signal has been applied to said reset terminal; and (b) responsive to an occurrence of one of the two possible conditions above, applying a signal to said reset terminal for at least a predetermined time period.
Claim 9
Independent Claim
72 words
A method of controlling a reset terminal, comprising the steps of: (a) detecting when either (1) a power supply voltage magnitude becomes less than a first voltage or (2) a reset terminal voltage indicates a reset signal has been applied to said reset terminal; and (b) responsive to an occurrence of one of the two possible conditions above, applying a signal to said reset terminal for at least a predetermined time period.
Claim 10
Dependent Claim
21 words
The method of claim 6, wherein: (a) said applying a signal includes connecting said reset terminal to a reference voltage supply.
Claim 11
Dependent Claim
20 words
The integrated circuit of claim 5, wherein: (a) said power supply voltage detector includes a temperature compensated voltage reference generator.
Claim 12
Dependent Claim
56 words
The integrated circuit of claim 5, wherein: (a) said power supply voltage detector detects when a power supply voltage falls below a first preselected fraction of a nominal power supply voltage; and (b) a detected external reset signal at said reset terminal is a voltage falling below a second preselected fraction of aid power supply voltage.
Claim 13
Dependent Claim
68 words
The integrated circuit of claim 9, further comprising: (a) a second reset terminal voltage detector connected to said reset terminal and to said control circuitry; and (b) said control circuitry outputs a second reset signal at said reset terminal when said second reset terminal detector detects a voltage rising above a third preselected fraction of said power supply voltage following a prior reset signal by said control circuitry.
References Cited (Backward Citations)
US4296338A
Cited
US4367422A
Cited
US4433390A
Cited
US4473759A
Cited
US4523104A
Cited
US4882506A
Cited
US4902910A
Cited
US4945300A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-11-17 | 1996-05-18 | 1996-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-17 | 2000-05-18 | 2000-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-17 | 2004-05-18 | 2004-11-17 | $7700.00 | Window Closed / Lapsed |