US4639615A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trimmable loading elements to control clock skew
Assignee: Nokia Bell Labs
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Filing: 1983-12-28
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Granted: 1987-01-27
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Expires: 2003-12-28
Abstract
Abstract An integrated circuit chip in which clock pulses are distributed to a plurality of circuits includes a pattern of trimmable elements such as capacitors or transistors. The capacitors or transistors are trimmed during manufacture in order, for example, to adjust clock skew.
Inventors
- 👤 Charles M. Lee
- 👤 Bernard T. Murphy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:20
CPC Classifications
G; G06; G06F; G06F1/00; G06F1/04; G06F1/10; H; H03; H03K; H03K19/00; H03K19/02; H03K19/173; H03K19/1733; H03K19/1735; H10; H10D; H10D89/00; H10D89/10; H03K5/00; H03K2005/00013; H03K2005/00078; H03K2005/00084; H03K2005/00091; H03K2005/0015; H03K2005/00195
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
115 words
A semiconductor integrated circuit comprising: clock means for generating clock pulses; first and second logic circuits each having an output node and controlled by said clock means; means for coupling clock pulses from said clock means to a first node connected to said first logic circuit; and means for coupling clock pulses from said clock means to a second node connected to said second logic circuit, characterized in that said integrated circuit further comprises at least one trimmable element connected to said first node and adapted to adjusting the skew of the clock pulses developed at said first logic circuit output node with respect to the clock pulses at said second logic circuit output node.
Claim 2
Dependent Claim
115 words
A semiconductor integrated circuit comprising: clock means for generating clock pulses; first and second logic circuits each having an output node and controlled by said clock means; means for coupling clock pulses from said clock means to a first node connected to said first logic circuit; and means for coupling clock pulses from said clock means to a second node connected to said second logic circuit, characterized in that said integrated circuit further comprises at least one trimmable element connected to said first node and adapted to adjusting the skew of the clock pulses developed at said first logic circuit output node with respect to the clock pulses at said second logic circuit output node.
Claim 3
Dependent Claim
50 words
The integrated circuit of claim 1 wherein said first logic circuit comprises an output circuit connected between said first node and a first output of said integrated circuit, and said second logic circuit comprises an output circuit connected between said second node and a second output of said integrated circuit.
Claim 4
Dependent Claim
21 words
The integrated circuit of claim 2 wherein said first and second output circuits each comprise a plurality of cascade-connected inverting amplifiers.
Claim 5
Dependent Claim
46 words
The integrated circuit of claim 1 wherein said at least one trimmable element comprises a p-channel field effect transistor and an n-channel field effect transistor having their gates connected together, their sources connected to power supply voltage means, and their drains connected together through fusible leads.
Claim 6
Dependent Claim
50 words
The integrated circuit of claim 1 further comprising a databus and a plurality of external pads, one for each bit of the databus, whereby trimming the trimmable element connected to said first node minimizes the amount of clock skew between at least two of said bits at said external pads.
Claim 7
Dependent Claim
29 words
The integrated circuit of claim 1 wherein said at least one trimmable element is connected between said first node and a source of electrical potential on said integrated circuit.
Claim 8
Dependent Claim
16 words
The integrated circuit of claim 1 wherein said at least one trimmable element is a capacitor.
Claim 9
Dependent Claim
22 words
The integrated circuit of claim 1 wherein said at least one trimmable element is a capacitor having a fusible lead connected thereto.
Claim 10
Dependent Claim
34 words
The integrated circuit of claim 1 wherein said at least one trimmable element is plurality of capacitors having capacitance values proportional to 2 0 , 2 1 , 2 2 . . . .
Claim 11
Dependent Claim
26 words
The integrated circuit of claim 1 wherein said at least one trimmable element is adapted to being trimmed by means of a fusible lead connected thereto.
Claim 12
Dependent Claim
23 words
The integrated circuit of claim 1 wherein said fusible lead is adapted to being opened by the application of an electrical current thereto.
Claim 13
Dependent Claim
22 words
The integrated circuit of claim 10 wherein said fusible lead is adapted to being opened by the application of a laser thereto.
References Cited (Backward Citations)
US4016483A
Cited
US4100437A
Cited
US4122995A
Cited
US4228528A
Cited
US4228528B1
Cited
US4228528B2
Cited
US4424456A
Cited
US4516312A
Cited
US4499387A
Cited
US4507576A
Cited
US4479216A
Cited
US4550405A
Cited
US4508983A
Cited
US4542505A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-26 | 1990-07-28 | 1991-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-26 | 1994-07-28 | 1995-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-26 | 1998-07-28 | 1999-01-27 | $7700.00 | Window Closed / Lapsed |