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US7026859B2 Expired / Lapsed US ⏱️ 0.0 years remaining

Control circuit for delay locked loop

Assignee: Mimirip LLC
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Filing: 2004-06-28
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Granted: 2006-04-11
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Expires: 2024-06-28
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Abstract

Abstract Provided is directed to a delay locked loop control circuit capable of reducing a test time and preventing a yield from being reduced, by preventing a failure due to a charge sharing and a failure in a specific frequency and voltage due to a noise of a feedback clock, by means of including: a level setting unit for setting an initial level of a locked state signal, which is decided whether or not phases of a reference clock and a feedback clock are aligned; a signal generation unit for generating a third control signal according to a first control signal comparing phases of the reference clock and the feedback clock, and a second control signal checking out phases of the reference clock and the feedback clock in every predetermined time; a level maintaining unit for maintaining a level of the locked state signal according to the locked state signal and a fourth control signal comparing a signal delaying the feedback clock for a predetermined time with the reference clock; a detection unit for varying a level of the locked state signal by detecting whether or not phases of a reference clock and a feedback clock are aligned according to the first to third control signals; and a control unit for controlling a variation of the locked state signal by means of the detection unit according to the fourth control signal.

Inventors

  • 👤 Sun Suk Yang
  • 👤 Byoung Jin Choi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 19:20
CPC Classifications
G; G11; G11C; G11C7/00; G11C7/22; H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/095; G11C11/00; G11C11/21; G11C11/34; G11C11/40; G11C11/401; G11C11/4063; G11C11/407; G11C11/4076; G11C7/10; G11C7/1006; H03L7/081; H03L7/0812; H03L7/0818

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 234 words
A delay locked loop control circuit, comprising: a latch connected to a first node for latching a locked state signal; a level setting unit for setting an initial level of the locked state signal, which is decided whether or not phases of a reference clock and a feedback clock are aligned; a signal generation unit for generating a third control signal according to a first control signal, the first control signal is a phase difference indicating the result of phases comparison of the reference clock and the feedback clock, and a second control signal, the second control signal is for checking out phases of the reference clock and the feedback clock in every predetermined time; a level maintaining unit for maintaining a level of the locked state signal according to the locked state signal and a fourth control signal outputted from a phase detector, the fourth control signal is a phase difference indicating the result of phases comparison of a signal delaying the feedback clock for a predetermined time with the reference clock; a detection unit for varying a level of the locked state signal by detecting whether or not phases of the reference clock and the feedback clock are aligned according to the first to third control signals; and a control unit for controlling a variation of the locked state signal by means of the detection unit according to the fourth control signal.
Claim 2
Dependent Claim 234 words
A delay locked loop control circuit, comprising: a latch connected to a first node for latching a locked state signal; a level setting unit for setting an initial level of the locked state signal, which is decided whether or not phases of a reference clock and a feedback clock are aligned; a signal generation unit for generating a third control signal according to a first control signal, the first control signal is a phase difference indicating the result of phases comparison of the reference clock and the feedback clock, and a second control signal, the second control signal is for checking out phases of the reference clock and the feedback clock in every predetermined time; a level maintaining unit for maintaining a level of the locked state signal according to the locked state signal and a fourth control signal outputted from a phase detector, the fourth control signal is a phase difference indicating the result of phases comparison of a signal delaying the feedback clock for a predetermined time with the reference clock; a detection unit for varying a level of the locked state signal by detecting whether or not phases of the reference clock and the feedback clock are aligned according to the first to third control signals; and a control unit for controlling a variation of the locked state signal by means of the detection unit according to the fourth control signal.
Claim 3
Dependent Claim 51 words
The delay locked loop control circuit of claim 1 , wherein the level setting unit includes: an inverter for inverting a reset signal; and a PMOS transistor for setting the initial level of the locked state signal by applying a power supply voltage according to an output signal of the inverter.
Claim 4
Dependent Claim 66 words
The delay locked loop control circuit of claim 1 , wherein the level maintaining unit includes: a first PMOS transistor connected to a power supply terminal for applying the power supply voltage according to the locked state signal; and a second PMOS transistor connected between the first PMOS transistor and the first node, and operated according to the fourth control signal outputted from the phase detector.
Claim 5
Dependent Claim 34 words
The delay locked loop control circuit of claim 1 , wherein the detection unit includes a plurality of NMOS transistors driven according to the first to third control signals, respectively, and connected in series.
Claim 6
Dependent Claim 25 words
The delay locked loop control circuit of claim 1 , wherein the control unit includes a NMOS transistor driven according to the fourth control signal.

References Cited (Backward Citations)

US5304867A Cited
US5982218A Cited
US5986443A Cited
US6346823B1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2009-04-10 2009-10-10 2010-04-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2013-04-10 2013-10-10 2014-04-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2017-04-10 2017-10-10 2018-04-11 $7700.00 Window Closed / Lapsed

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