← Back to Patent Explorer
US6002281A Expired / Lapsed US ⏱️ 0.0 years remaining

Delay locked loop

Assignee: Intel Corp
•
Filing: 1998-02-20
•
Granted: 1999-12-14
•
Expires: 2018-02-20
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract An apparatus comprising a first circuit configured to receive a first clock signal and delaying the first clock signal by a first delay to generate a second clock signal, the first delay being a first function of a first signal; a phase-frequency detector configured to receive the first clock signal and the second clock signal and generate a second signal dependent on the first delay; a second circuit configured to receive tile second signal and generate a third signal, the third signal being a digital signal; and a current mirror configured to generate the first signal, the first signal being a second function of the third signal.

Inventors

  • 👤 Matthew S. Jones
  • 👤 Babak B. Nikjou
  • 👤 Morteza C. Afghahi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 22:52
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/10; H03L7/104; H03L7/081; H03L7/0812; H03L7/0814; H03L7/0816

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 108 words
An apparatus comprising: a first circuit configured to receive a first clock signal and delaying the first clock signal by a first delay to generate a second clock signal, the first delay being a first function of a first signal; a phase-frequency detector configured to receive the first clock signal and the second clock signal and generate a second signal dependent on the first delay; a second circuit configured to receive the second signal and generate a third signal, the third signal being a digital signal; and a digital current mirror configured to generate the first signal, the first signal being a second function of the third signal.
Claim 2
Independent Claim 108 words
An apparatus comprising: a first circuit configured to receive a first clock signal and delaying the first clock signal by a first delay to generate a second clock signal, the first delay being a first function of a first signal; a phase-frequency detector configured to receive the first clock signal and the second clock signal and generate a second signal dependent on the first delay; a second circuit configured to receive the second signal and generate a third signal, the third signal being a digital signal; and a digital current mirror configured to generate the first signal, the first signal being a second function of the third signal.
Claim 3
Dependent Claim 40 words
The apparatus of claim 1 wherein the first circuit comprises a plurality of delay elements coupled in series, each of the plurality of delay elements having a second delay, the second delay being a third function of the first signal.
Claim 4
Dependent Claim 141 words
The apparatus of claim 2 wherein at least one of the plurality of delay elements has an input an an output, the delay element comprising an inverter having a plurality of p-type transistors coupled in series to the output and a plurality of n-type transistors coupled in series to the output, a first p-type transistor of the plurality of p-type transistors having a first gate coupled to the input and a second n-type transistor of the plurality of n-type transistors having a second gate coupled to the input, a third p-type transistor of the plurality of p-type transistors having a third gate coupled to receive a first voltage and a fourth n-type transistor of the plurality of n-type transistors having a fourth gate coupled to receive the second voltage, the first and second voltage being a function of the first signal.
Claim 5
Dependent Claim 49 words
The apparatus of claim 3 wherein a fifth p-type transistor of the plurality of p-type transistors having a fifth gate is coupled to receive a third voltage and a sixth n-type transistor of the plurality of n-type transistors having a sixth gate is coupled to receive a fourth voltage.
Claim 6
Dependent Claim 153 words
The apparatus of claim 1 wherein the second signal comprises a fifth signal and a sixth signal, wherein the phase-frequency detector is configured to generate the fifth signal and the sixth signal, the fifth signal being asserted when the first clock signal is asserted and the second clock signal is deasserted and the sixth signal being asserted when the first clock signal is deasserted and the second clock signal is asserted; and wherein the second circuit comprises a fourth circuit configured to receive the fifth signal and the sixth signal and generate a seventh signal and an eighth signal, the seventh signal being asserted in response to a first assertion of the first signal and deasserted in response to a second assertion of the first signal, the eighth signal being asserted in response to a third assertion of the second signal and deasserted in response to a fourth assertion of the second signal.
Claim 7
Dependent Claim 43 words
The apparatus of claim 2 wherein the second circuit comprises an arithmetic unit configured t o receive the second signal and generate the third signal, the third signal having a value, the arithmetic unit modifying the value in response to the second signal.
Claim 8
Dependent Claim 13 words
The apparatus of claim 6 wherein the arithmetic unit is an up-down counter.
Claim 9
Dependent Claim 29 words
The apparatus of claim 6 wherein arithmetic unit is configured to receive an initialization signal and initialize the value to a first value in response to the initialization signal.
Claim 10
Dependent Claim 21 words
The apparatus of claim 8 further comprising an initialization circuit configured to assert the initialization signal upon a power up operation.
Claim 11
Dependent Claim 20 words
The apparatus of claim 8 further comprising an initialization circuit configured to assert the initialization signal upon a reset operation.
Claim 12
Dependent Claim 62 words
The apparatus of claim 1 wherein the current mirror comprises a first variable resistor to generate a first voltage and a second variable resistor to generate a second voltage, and wherein the third signal has a value, the first variable resistor having a first resistance corresponding to the value and the second variable resistor having a second resistance corresponding to the value.
Claim 13
Independent Claim 84 words
A method for generating a second clock signal comprising the steps of: receiving a first clock signal; delaying the first clock signal by a first delay to generate the second clock signal, the first delay being a first function of a first signal; generating a second signal dependent on the first delay; generating a third signal based on the second signal, the third signal being a digital signal; and generating the first signal, the first signal being a second function of the third signal.
Claim 14
Independent Claim 84 words
A method for generating a second clock signal comprising the steps of: receiving a first clock signal; delaying the first clock signal by a first delay to generate the second clock signal, the first delay being a first function of a first signal; generating a second signal dependent on the first delay; generating a third signal based on the second signal, the third signal being a digital signal; and generating the first signal, the first signal being a second function of the third signal.
Claim 15
Dependent Claim 115 words
The method of claim 12 further comprising the steps of: asserting a fifth signal when the first clock signal is asserted and the second clock signal is deasserted; asserting a sixth signal when the first clock signal is deasserted and the second clock signal is asserted; asserting a seventh signal in response to a first assertion of the first signal; deasserting the seventh signal in response to a second assertion of the first signal; asserting an eighth signal in response to a third assertion of the second signal; and deasserting the eighth signal in response to a fourth assertion of the second signal, wherein the second signal comprises the fifth signal and the sixth signal.
Claim 16
Dependent Claim 28 words
The method of claim 12 wherein the third signal has a value, the method further comprising the step of modifying the value in response to the second signal.
Claim 17
Dependent Claim 19 words
The method of claim 14 further comprising the step of incrementing the value in response to the second signal.
Claim 18
Dependent Claim 19 words
The method of claim 14 further comprising the step of decrementing the value in response to the second signal.
Claim 19
Dependent Claim 28 words
The method of claim 14 further comprising the step of: generating an initialization signal; and initializing the value to a first value in response to the initialization signal.
Claim 20
Dependent Claim 20 words
The method of claim 17 wherein the step of generating the initialization signal is performed during a power up operation.
Claim 21
Dependent Claim 19 words
The method of claim 17 wherein the step of generating the initialization signal is performed during a reset operation.

References Cited (Backward Citations)

US5815016A Cited
US5629897A Cited
US5684421A Cited
US5831465A Cited
US5790612A Cited
US5854797A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2002-12-13 2003-06-14 2003-12-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-12-13 2007-06-14 2007-12-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-12-13 2011-06-14 2011-12-14 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag