Patent US3026602A successfully refreshed from Google Patents.
Patent US6204705B1 successfully refreshed from Google Patents.
← Back to Patent Explorer
US6204705B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Delay locked loop for sub-micron single-poly digital CMOS processes

Assignee: Microchip Technology Inc
•
Filing: 1999-05-28
•
Granted: 2001-03-20
•
Expires: 2019-05-28
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A delay locked loop includes a delay circuit capable of generating an output clock and further capable of generating a GATE signal in response to an aliased condition. A phase detector is coupled to the delay circuit and is capable of comparing a phase difference between a reference clock and the output clock from the delay circuit and generating a pump up signal if the output clock is lagging the reference clock. The phase detector is capable of generating a pump down signal if the output clock is leading the reference clock. A charge pump is coupled to the phase detector and is capable of generating a control voltage for controlling the delay provided to the output clock and capable of pulling up the control voltage in response to the GATE signal. A method of phase locking an output clock with a reference clock includes, checking the occurrence of an aliased condition, increasing the speed of the output clock in response to an aliased condition, and increasing the speed of the output clock if the output clock is lagging the reference clock and decreasing the speed of the output clock if the output clock is leading the reference clock.

Inventors

  • 👤 Jung-Chen Lin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 20:49
CPC Classifications
G; G06; G06F; G06F1/00; G06F1/04; G06F1/10; H; H03; H03K; H03K5/00; H03K5/13; H03K5/133; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/081; H03L7/0812; H03L7/0816; H03L7/085; H03L7/089; H03L7/0891; H03L7/0895; H03K2005/00013; H03K2005/00019; H03K2005/00026; H03K2005/00032; H03K2005/00039; H03K2005/00045

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 211 words
A delay locked loop comprising: a delay circuit for generating an output clock signal (Fbkclk), transmitting a reference clock signal (Refclk), and further for generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); a phase detector coupled to the delay circuit and for comparing a phase difference between the reference clock signal (Refclk) and the output clock signal (Fbkclk) from the delay circuit and generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and a charge pump coupled to the phase detector and for generating a charge pump output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk).
Claim 2
Dependent Claim 211 words
A delay locked loop comprising: a delay circuit for generating an output clock signal (Fbkclk), transmitting a reference clock signal (Refclk), and further for generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); a phase detector coupled to the delay circuit and for comparing a phase difference between the reference clock signal (Refclk) and the output clock signal (Fbkclk) from the delay circuit and generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and a charge pump coupled to the phase detector and for generating a charge pump output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk).
Claim 3
Dependent Claim 118 words
The delay locked loop of claim 1 wherein the phase detector comprises: a first NAND gate for receiving the reference clock signal (Refclk) and a supply voltage signal; a second NAND gate for receiving the output clock signal (Fbkclk) and the GATE signal; a third NAND gate coupled to an output of the first NAND gate and for receiving the GATE signal; a fourth NAND gate coupled to an output of the second NAND gate and configured to receive the supply voltage signal; and a NAND gate stage coupled to an output of the third NAND gate and an output of the fourth NAND gate and capable of generating the pump up signal and the pump down signal.
Claim 4
Dependent Claim 135 words
The delay locked loop of claim 1 wherein the charge pump comprises: a pull-up current source responsive to the values of the pump up signal and the GATE signal and for increasing a value of the charge pump output control voltage; a pull-down current source responsive to the values of the pump down signal and the GATE signal and for decreasing the value of the charge pump output control voltage; a pull-up transistor responsive to the value of the GATE signal and having a first terminal coupled to a supply voltage source, the pull-up transistor further including a second terminal and for increasing the value of the charge pump output control voltage; and a capacitor coupled to the second terminal of the pull-up transistor for storing the value of the charge pump output control voltage.
Claim 5
Dependent Claim 55 words
The delay locked loop of claim 1 wherein the delay circuit comprises: a plurality of delay cells for generating the output clock signal (Fbkclk); an inverter for generating the reference clock signal (Refclk); and a flip-flop coupled to the inverter and to at least some of the delay cells and for generating the GATE signal.
Claim 6
Dependent Claim 200 words
A delay locked loop comprising: means for generating an output clock signal (Fbkclk), for transmitting a reference clock signal (Refclk), and for generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); coupled to the means for generating, means for comparing a phase difference between a reference clock signal (Refclk) and the output clock signal (Fbkclk) and for generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and coupled to the means for comparing, means for generating an output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk).
Claim 7
Dependent Claim 200 words
A delay locked loop comprising: means for generating an output clock signal (Fbkclk), for transmitting a reference clock signal (Refclk), and for generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); coupled to the means for generating, means for comparing a phase difference between a reference clock signal (Refclk) and the output clock signal (Fbkclk) and for generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and coupled to the means for comparing, means for generating an output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk).
Claim 8
Independent Claim 135 words
A method of phase locking an output clock (Fbkclk) with a reference clock (Refclk), the method comprising: checking the occurrence of an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); increasing the speed of the output clock (Fbkclk) in response to an aliased condition so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); and increasing the speed of the output clock (Fbkclk) if the output clock (Fbkclk) is lagging the reference clock (Refclk) and decreasing the speed of the output clock (Fbkclk) if the output clock (Fbkclk) is leading the reference clock (Refclk).
Claim 9
Independent Claim 135 words
A method of phase locking an output clock (Fbkclk) with a reference clock (Refclk), the method comprising: checking the occurrence of an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); increasing the speed of the output clock (Fbkclk) in response to an aliased condition so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); and increasing the speed of the output clock (Fbkclk) if the output clock (Fbkclk) is lagging the reference clock (Refclk) and decreasing the speed of the output clock (Fbkclk) if the output clock (Fbkclk) is leading the reference clock (Refclk).
Claim 10
Dependent Claim 321 words
A delay locked loop comprising: a delay circuit for generating an output clock signal (Fbkclk), transmitting a reference clock signal (Refclk), and further for generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); a phase detector coupled to the delay circuit and for comparing a phase difference between the reference clock signal (Refclk) and the output clock signal (Fbkclk) from the delay circuit and generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and a charge pump coupled to the phase detector and for generating a charge pump output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); wherein the phase detector comprises: a first NAND gate for receiving the reference clock signal (Refclk) and a supply voltage signal; a second NAND gate for receiving the output clock signal (Fbkclk) and the GATE signal; a third NAND gate coupled to an output of the first NAND gate and for receiving the GATE signal; a fourth NAND gate coupled to an output of the second NAND gate and configured to receive the supply voltage signal; and a NAND gate stage coupled to an output of the third NAND gate and an output of the fourth NAND gate and for generating the pump up signal and the pump down signal.
Claim 11
Dependent Claim 321 words
A delay locked loop comprising: a delay circuit for generating an output clock signal (Fbkclk), transmitting a reference clock signal (Refclk), and further for generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); a phase detector coupled to the delay circuit and for comparing a phase difference between the reference clock signal (Refclk) and the output clock signal (Fbkclk) from the delay circuit and generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and a charge pump coupled to the phase detector and for generating a charge pump output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); wherein the phase detector comprises: a first NAND gate for receiving the reference clock signal (Refclk) and a supply voltage signal; a second NAND gate for receiving the output clock signal (Fbkclk) and the GATE signal; a third NAND gate coupled to an output of the first NAND gate and for receiving the GATE signal; a fourth NAND gate coupled to an output of the second NAND gate and configured to receive the supply voltage signal; and a NAND gate stage coupled to an output of the third NAND gate and an output of the fourth NAND gate and for generating the pump up signal and the pump down signal.
Claim 12
Dependent Claim 336 words
A delay locked loop comprising: a delay circuit generating an output clock signal (Fbkclk), transmitting a reference clock signal (Refclk), and further generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); a phase detector coupled to the delay circuit and comparing a phase difference between the reference clock signal (Refclk) and the output clock signal (Fbkclk) from the delay circuit and generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and a charge pump coupled to the phase detector and for generating a charge pump output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); wherein the charge pump comprises: a pull-up current source responsive to the values of the pump up signal and the GATE signal and for increasing a value of the charge pump output control voltage; a pull-down current source responsive to the values of the pump down signal and the GATE signal and for decreasing the value of the charge pump output control voltage; a pull-up transistor responsive to the value of the GATE signal and having a first terminal coupled to a supply voltage source, the pull-up transistor further including a second terminal and for increasing the value of the charge pump output control voltage; and a capacitor coupled to the second terminal of the pull-up transistor for storing the value of the charge pump output control voltage.
Claim 13
Dependent Claim 336 words
A delay locked loop comprising: a delay circuit generating an output clock signal (Fbkclk), transmitting a reference clock signal (Refclk), and further generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); a phase detector coupled to the delay circuit and comparing a phase difference between the reference clock signal (Refclk) and the output clock signal (Fbkclk) from the delay circuit and generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and a charge pump coupled to the phase detector and for generating a charge pump output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); wherein the charge pump comprises: a pull-up current source responsive to the values of the pump up signal and the GATE signal and for increasing a value of the charge pump output control voltage; a pull-down current source responsive to the values of the pump down signal and the GATE signal and for decreasing the value of the charge pump output control voltage; a pull-up transistor responsive to the value of the GATE signal and having a first terminal coupled to a supply voltage source, the pull-up transistor further including a second terminal and for increasing the value of the charge pump output control voltage; and a capacitor coupled to the second terminal of the pull-up transistor for storing the value of the charge pump output control voltage.
Claim 14
Dependent Claim 259 words
A delay locked loop comprising: a delay circuit for generating an output clock signal (Fbkclk), transmitting a reference clock signal (Refclk), and further for generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); a phase detector coupled to the delay circuit and for comparing a phase difference between the reference clock signal (Refclk) and the output clock signal (Fbkclk) from the delay circuit and generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and a charge pump coupled to the phase detector and for generating a charge pump output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); wherein the delay circuit comprises: a plurality of delay cells for generating the output clock signal (Fbkclk); an inverter for generating the reference clock signal (Refclk); and a flip-flop coupled to the inverter and to at least some of the delay cells and for generating the GATE signal.
Claim 15
Dependent Claim 259 words
A delay locked loop comprising: a delay circuit for generating an output clock signal (Fbkclk), transmitting a reference clock signal (Refclk), and further for generating a GATE signal in response to an aliased condition, wherein the aliased condition occurs when the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); a phase detector coupled to the delay circuit and for comparing a phase difference between the reference clock signal (Refclk) and the output clock signal (Fbkclk) from the delay circuit and generating a pump up signal if the output clock signal (Fbkclk) is lagging the reference clock signal (Refclk) and a pump down signal if the output clock signal (Fbkclk) is leading the reference clock signal (Refclk); and a charge pump coupled to the phase detector and for generating a charge pump output control voltage for controlling the delay provided to the output clock signal (Fbkclk) and for pulling up the output control voltage in response to the GATE signal to increase the speed of the output clock signal (Fbkclk) so that the output clock signal (Fbkclk) does not lag the reference clock signal (Refclk) by more than one clock period of the reference clock signal (Refclk); wherein the delay circuit comprises: a plurality of delay cells for generating the output clock signal (Fbkclk); an inverter for generating the reference clock signal (Refclk); and a flip-flop coupled to the inverter and to at least some of the delay cells and for generating the GATE signal.

References Cited (Backward Citations)

US5267269A Cited
US5712884A Cited
US6043695A Cited
US6008680A Cited
US5994934A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2004-03-19 2004-09-18 2005-03-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2008-03-19 2008-09-18 2009-03-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2012-03-19 2012-09-18 2013-03-20 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag