Invention Grant
- Patent Title: Dual loop architecture useful for a programmable clock source and clock multiplier applications
- Patent Title (中): 双循环架构可用于可编程时钟源和时钟乘法器应用
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Application No.: US12249457Application Date: 2008-10-10
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Publication No.: US07825708B2Publication Date: 2010-11-02
- Inventor: Axel Thomsen , Yunteng Huang , Jerrell P. Hein
- Applicant: Axel Thomsen , Yunteng Huang , Jerrell P. Hein
- Applicant Address: US TX Austin
- Assignee: Silicon Laboratories Inc.
- Current Assignee: Silicon Laboratories Inc.
- Current Assignee Address: US TX Austin
- Agency: Zagorin O'Brien Graham LLP
- Main IPC: H03L7/06
- IPC: H03L7/06

Abstract:
A first phase-locked loop (PLL) circuit includes an input for receiving a timing reference signal from an oscillator, a controllable oscillator circuit supplying an oscillator output signal, and a multi-modulus feedback divider circuit. A second control loop circuit is selectably coupled through a select circuit to supply a digital control value (M) to the multi-modulus feedback divider circuit of the first loop circuit to thereby control the oscillator output signal. While the second control loop is coupled to supply the control value to the feedback divider circuit, the control value is determined according to a detected difference between the oscillator output signal and a reference signal coupled to the second control loop circuit at a divider circuit. While the second control loop circuit is not coupled to control the first PLL circuit, the first PLL circuit receives a digital control value to control a divide ratio of the feedback divider, the digital control value is determined at least in part according to a stored control value stored in nonvolatile storage, the stored control value corresponding to a desired frequency of the oscillator output signal.
Public/Granted literature
- US20090039968A1 DUAL LOOP ARCHITECTURE USEFUL FOR A PROGRAMMABLE CLOCK SOURCE AND CLOCK MULTIPLIER APPLICATIONS Public/Granted day:2009-02-12
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