Invention Grant
- Patent Title: Semiconductor device
- Patent Title (中): 半导体器件
-
Application No.: US12753471Application Date: 2010-04-02
-
Publication No.: US08008955B2Publication Date: 2011-08-30
- Inventor: Masafumi Kondou
- Applicant: Masafumi Kondou
- Applicant Address: JP Kawasaki
- Assignee: Fujitsu Limited
- Current Assignee: Fujitsu Limited
- Current Assignee Address: JP Kawasaki
- Agency: Arent Fox LLP
- Priority: JP2009-096500 20090410
- Main IPC: H03L7/06
- IPC: H03L7/06

Abstract:
There is provided a semiconductor device having a voltage-controlled oscillator outputting an output clock signal; N pieces of control units generating a frequency-divided clock signal by frequency-dividing the output clock signal, comparing a reference clock signal and the frequency-divided clock signal, and outputting an output signal based on a comparison result; an adder adding output signals from each of the control units; and a low-pass filter filtering an output of the adder and outputting to the voltage-controlled oscillator, wherein setting information related to a frequency division ratio made of N pieces of data cycled and supplied in a sequence in synchronization with the frequency-divided clock signal is supplied to each of the control units with initial values made different from one another and a frequency-division operation and a comparison operation are performed thereby to form a moving average filter by N pieces of control units and to reduce a quantization noise, so that occurrence of a spurious in the output clock signal can be suppressed.
Public/Granted literature
- US20100259307A1 SEMICONDUCTOR DEVICE Public/Granted day:2010-10-14
Information query