Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Delta Sigma Fractional-N Synthesizer

Status
Not open for further replies.

iemotions

Junior Member level 3
Joined
Mar 11, 2004
Messages
25
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
208
fractional n synth

Does anyone have lectures about the operational

concepts about Delta Sigma Modulator used in F-N Syn.

What I get after consulting Master Google is so

tough that my stupid mind can't realize how Delta-Sigma

mechanism can move the spur noise to high frequency

and lower the spur noise power

by stupid newfresh man
 

nathanee

Junior Member level 3
Joined
May 1, 2004
Messages
31
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
239
sigma-delta n divider noise transfer function

There is a slides fyi.

Regards,

-nathanee
 

hawind

Junior Member level 1
Joined
Jul 27, 2003
Messages
19
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Activity points
84
delta-sigma fractional-n synthesizers

This is a lecture from KU leuven.
 
  • Like
Reactions: akhelo

    akhelo

    Points: 2
    Helpful Answer Positive Rating

toonafishy

Full Member level 6
Joined
Jun 18, 2002
Messages
369
Helped
38
Reputation
76
Reaction score
12
Trophy points
1,298
Location
Earth
Activity points
3,178
delta sigma fractional-n synthesizer

Try this...
 

refdv

Newbie level 4
Joined
May 9, 2004
Messages
7
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
70
fractional-n synthesizer

The basic function of sigma delta modulator is to feedback the noise and from the output to the input this will make the noise higher but it is pushed outside of the signal bandwidth. This will reduce the noise in the signal!!
 

jerryhuang

Member level 1
Joined
Feb 3, 2005
Messages
38
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
357
fractional n synthesizer

dose someone have some paper about mash sigma delta ?can give me a clear conception about that
 

kjjian

Junior Member level 2
Joined
Dec 2, 2005
Messages
22
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Activity points
1,448
delta-sigma fractional-n synthesizer

I think this is good:
"Sigma-Delta
Fractional-N Frequency Synthesis"
Scott Meninger
Michael Perrott
Massachusetts Institute of Technology
 

marcel

Newbie level 5
Joined
Oct 13, 2004
Messages
8
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,283
Activity points
56
thanks for nathanee! Do you have any further documents about fractional frequency synthesizer?
 

RDRyan

Full Member level 2
Joined
May 24, 2007
Messages
133
Helped
20
Reputation
40
Reaction score
3
Trophy points
1,298
Location
China
Activity points
1,976
"how Delta-Sigma mechanism can move the spur noise to high frequency and lower the spur noise power "

To iemotions
The Delta-Sigma modulator has the transfer function as below:
Y(z)=X(z)-N(z)*(1-z^-1)^n
for noise N(z), it is high pass
for signal X(z), it is all pass
The qutization noise from Divider of the fractional N PLL is high passed by delta sigma modulator.
so the low frequency spurs noise is supressed and moved to high frequency.
 

pillar_chen

Member level 3
Joined
Nov 2, 2005
Messages
59
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Activity points
1,682
are there some introduction papers on the fractional N synthesizer?
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top