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Patent US5498989A successfully refreshed from Google Patents.
US5498989A
Expired / Lapsed
US
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Integrated circuit one shot with extended length output pulse
Assignee: Xilinx Inc
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Filing: 1994-04-19
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Granted: 1996-03-12
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Expires: 2014-04-19
Abstract
Abstract An integrated circuit one shot circuit provides relatively long duration (hundreds of nanoseconds up to a millisecond) output pulses without the need for excessively large transistors. The one shot circuit includes a pull up and a pull down device connected to the one shot circuit's input terminal, with a latch connected to a node between the pull up and pull down devices. The output terminal of the latch is connected to the input of a Schmitt trigger. One terminal of a grounded capacitor is connected between the latch output terminal and the Schmitt trigger input. The output terminal of the Schmitt trigger is connected through an inverter to one input terminal of a NAND gate, the other input terminal of which is connected to the one shot circuit's input terminal. A feedback line connects the output terminal of the NAND gate to the gate of a depletion mode transistor which is between the pull up and pull down devices. This provides a glitch free long duration output pulse using conventional CMOS transistor fabrication technology in a large scale integrated circuit.
Inventors
- 👤 Sholeh Diba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:28
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/153; H03K5/1534; H03K3/00; H03K3/02; H03K3/027; H03K3/033
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
116 words
A one shot circuit comprising: an input terminal; a logic gate having a first logic gate input terminal connected to the input terminal thereby providing an unlatched signal from the input terminal to the logic gate; a pull-up device and a pull-down device each connected to the input terminal; a latch having an input terminal connected to the pull-up device and having an output terminal connected, by a buffering device, to a second logic gate input terminal of the logic gate thereby holding an output signal of the pull-up device; and a capacitor connected to the output terminal of the latch; wherein a one-shot output signal is provided at an output terminal of the logic gate.
Claim 2
Dependent Claim
116 words
A one shot circuit comprising: an input terminal; a logic gate having a first logic gate input terminal connected to the input terminal thereby providing an unlatched signal from the input terminal to the logic gate; a pull-up device and a pull-down device each connected to the input terminal; a latch having an input terminal connected to the pull-up device and having an output terminal connected, by a buffering device, to a second logic gate input terminal of the logic gate thereby holding an output signal of the pull-up device; and a capacitor connected to the output terminal of the latch; wherein a one-shot output signal is provided at an output terminal of the logic gate.
Claim 3
Dependent Claim
40 words
The circuit of claim 1, further comprising: an N-channel depletion device connected between said pull-up device and said pull-down device; and a feedback line connected from an output terminal of the logic gate to gate of the N-channel depletion device.
Claim 4
Dependent Claim
34 words
The circuit of claim 1, further comprising a deglitcher serially connected between the input terminal and the first logic gate input terminal thereby to filter irregularities from a signal applied to the input terminal.
Claim 5
Dependent Claim
27 words
The circuit of claim 3, wherein the deglitcher includes: two serially connected inverters; and a capacitor having one terminal connected to a node between the two inverters.
Claim 6
Dependent Claim
13 words
The circuit of claim 1, wherein the buffering device includes a Schmitt trigger.
Claim 7
Dependent Claim
19 words
The circuit of claim 1, further comprising two inverters serially connected to the output terminal of the logic gate.
Claim 8
Dependent Claim
22 words
The circuit of claim 2, wherein a size of the pull-up device is about seven times a size of the pull-down device.
Claim 9
Dependent Claim
22 words
The circuit of claim 2, wherein a size of the N-channel depletion device is 65 times a size of the pull-down device.
Claim 10
Independent Claim
53 words
A method of operating a one shot circuit comprising the steps of: providing an input signal; latching complement of the input signal to generate a latched signal; logically combining the input signal and the latched complement signal to form an output signal, the logical combination being a one-shot response to the input signal.
Claim 11
Independent Claim
53 words
A method of operating a one shot circuit comprising the steps of: providing an input signal; latching complement of the input signal to generate a latched signal; logically combining the input signal and the latched complement signal to form an output signal, the logical combination being a one-shot response to the input signal.
Claim 12
Dependent Claim
28 words
The method of claim 9, further comprising the step of: generating a delayed response to the output signal which causes the latched complement signal to switch more slowly.
Claim 13
Dependent Claim
34 words
The method of claim 9, further comprising the step of: setting a predetermined length of the output signal in the step of logically combining, by electrically storing a portion of the latched complement signal.
Claim 14
Dependent Claim
137 words
A one shot circuit, comprising: an input terminal; a logic gate having a first logic gate input terminal connected to the input terminal; a pull-up device and a pull-down device each connected to the input terminal; a latch having an input terminal connected to the pull-up device and having an output terminal connected, by a buffering device, to a second logic gate input terminal of the logic gate, thereby holding an output signal of the pull-up device; a capacitor connected to the output terminal of the latch; and a deglitcher serially connected between the input terminal and the first logic gate input terminal, thereby to filter irregularities from a signal applied to the input terminal, wherein the deglitcher includes: two serially connected inverters; and a capacitor having one terminal connected to a node between the two inverters.
Claim 15
Dependent Claim
137 words
A one shot circuit, comprising: an input terminal; a logic gate having a first logic gate input terminal connected to the input terminal; a pull-up device and a pull-down device each connected to the input terminal; a latch having an input terminal connected to the pull-up device and having an output terminal connected, by a buffering device, to a second logic gate input terminal of the logic gate, thereby holding an output signal of the pull-up device; a capacitor connected to the output terminal of the latch; and a deglitcher serially connected between the input terminal and the first logic gate input terminal, thereby to filter irregularities from a signal applied to the input terminal, wherein the deglitcher includes: two serially connected inverters; and a capacitor having one terminal connected to a node between the two inverters.
Claim 16
Dependent Claim
92 words
A one shot circuit comprising: an input terminal; a logic gate having a first logic gate input terminal connected to the input terminal; a pull-up device and a pull-down device each connected to the input terminal; a latch having an input terminal connected to the pull-up device and having an output terminal connected, by a buffering device including a Schmitt trigger, to a second logic gate input terminal of the logic gate, thereby holding an output signal of the pull-up device; and a capacitor connected to the output terminal of the latch.
Claim 17
Dependent Claim
92 words
A one shot circuit comprising: an input terminal; a logic gate having a first logic gate input terminal connected to the input terminal; a pull-up device and a pull-down device each connected to the input terminal; a latch having an input terminal connected to the pull-up device and having an output terminal connected, by a buffering device including a Schmitt trigger, to a second logic gate input terminal of the logic gate, thereby holding an output signal of the pull-up device; and a capacitor connected to the output terminal of the latch.
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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) | 1999-03-12 | 1999-09-11 | 2000-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-03-12 | 2003-09-11 | 2004-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-03-12 | 2007-09-11 | 2008-03-12 | $7700.00 | Window Closed / Lapsed |