Invention Grant
- Patent Title: Cascaded PLL for reducing low-frequency drift in holdover mode
- Patent Title (中): 级联PLL,用于降低保持模式下的低频漂移
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Application No.: US13766035Application Date: 2013-02-13
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Publication No.: US08791734B1Publication Date: 2014-07-29
- Inventor: Susumu Hara , Adam D. Eldredge , Jeffrey S. Batchelor , Daniel Gallant
- Applicant: Silicon Laboratories Inc.
- Applicant Address: US TX Austin
- Assignee: Silicon Laboratories Inc.
- Current Assignee: Silicon Laboratories Inc.
- Current Assignee Address: US TX Austin
- Agency: Abel Law Group, LLP
- Main IPC: H03L7/06
- IPC: H03L7/06

Abstract:
A cascaded phase-locked loop (PLL) clock generation technique reduces frequency drift of a low-jitter clock signal in a holdover mode. An apparatus includes a first PLL circuit configured to generate a control signal based on a first clock signal and a first divider value. The apparatus includes a second PLL circuit configured to generate the first clock signal based on a low-jitter clock signal and a second divider value. The apparatus includes a third PLL circuit configured to generate the second divider value based on the first clock signal, a third divider value, and a second clock signal. The low-jitter clock signal may have a greater temperature dependence than the second clock signal and the second clock signal may have a higher jitter than the low-jitter clock signal.
Public/Granted literature
- US20140225653A1 CASCADED PLL FOR REDUCING LOW-FREQUENCY DRIFT IN HOLDOVER MODE Public/Granted day:2014-08-14
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