kwak clock issues

Status
Not open for further replies.
Jump to Latest
#61
Re: Re: Re: completely useless remark?/ Ground Bounce

Elso Kwak said:


http://en.wikipedia.org/wiki/Ground_bounce

and references given there
and:
http://www.home.agilent.com/cgi-bin..._KEY=199279&LANGUAGE_CODE=eng&COUNTRY_CODE=US

http://www.eetchina.com/ARTICLES/2003OCT/PDF/2003OCT27_ST_HBM_AN.PDF
😎
Click to expand...

Hello Elso

It seems a though you are stuck on some misunderstanding, we are not arguing that when you connect the decoupling capacitor that one method of connection creates zero noise (no voltage drop) and the other method creates lots of noise (lots of voltage drop), both methods work but when you measure which method generates the least noise (EMC) you will find there is a better method these are measurable facts, reproducible by anybody.

Look at the following link these guys specialize and make a living out of is PCB layouts . Their products have an emphasis on low EMC layouts. http://www.ultracad.com/articles/todd_h.pdf
http://www.omnigraph.com/index1.html ( read article on "Maintaining clean Power").

Regards
Arthur
 
#62
Hi Arthur, Thanks for the articles.
Please read:
http://www.ultracad.com/articles/g_bounce.pdf

There is some confusion in
the industry about one aspect
of the placement. (a)
The bypass cap can be
placed close to the ground pin of the package,
which minimizes the inductance in the ground path
but increases it in the Vcc path. Or (b), the bypass
cap can be placed close to the Vcc pin, which
minimizes the inductance in the Vcc path but increases
it in the ground path. Or (c), we can place
the bypass cap half way between and equalize the
inductance in the two paths.
Most engineers instinctively think (a) is correct.
The Motorola FACT book, and at least one
speaker at a PCB Design Conference states that
(b) is the correct answer. I posted this question on
the IPC's DesignerCouncil e-mail forum (which I
encourage all of you to join*). The best answer I
got back was "I've been wondering the same thing.
When you find the answer let me know!" I called
an applications engineer at Motorola and read him
the paragraph from their own FACT book. His
response? "Gee, I'm not sure I agree with that!" If
any one has a definitive answer to this question, let
me know and I'll print it in this column. Until then,
here is the TRUTH (as interpreted by Brookspeak!)
Click to expand...
 
#66
#67
Re: 2 or 3 caps //

Elso Kwak said:

2 or even 3 caps parallel are often used yo get a low impedance across a wide frequency range. It's also in the Linear Technology Application Note page 25 and further.
The Goudreau triplet has some fame since many years......
http://www.audioasylum.com/audio/tweaks/messages/116534.html
😎
Click to expand...

Elso

You didn't get the joke. Obviously the caps should be in series, one at the Vcc side and one at the Vdd side.
 
#68
Elso Kwak said:
Hi Arthur, Thanks for the articles.
Please read:
http://www.ultracad.com/articles/g_bounce.pdf
Click to expand...
Hello Elso

I was wrong in using the term "ground bounce" to describe the the voltage drop caused by the different placements of the decoupling capacitor . Ground bounce occures due to mechanisms inside the IC itself namely the inductances between the VCC supply and chip die and GND and chip die as small leads which have inductance are used to connect the chip die to the solderable leads which connect to the PCB power supplies.

Regards
Arthur
 
#69
Well, the self made pcb of post 48 is working allright now. I have a feeling that it sounds better then first p2p version, better soundstage and more accurate to pinpoint, probably because of a better layout & the use of more SMD parts & the SMD comparator instead of a DIL. But it has to burn in for a while first.
Btw, could not get .01uF smd coupling caps, but placed .015uF, works fine.
 
#73
Ok your ears are more "golden" than mines. Must be my age......
Click to expand...
Elso, there is a possibility that i became more deaf then you are allready 🙂 But Bach was very deaf also......

The burn in is happening at this moment. Sound is improving. I now hear very very subsonic sounds, even from a tda1541A.......

But i suppose that a supply cap of the I/V (i used Elna Cerafine) requires a longer burn in period then a lytic for the clock supply.
And no, didn't use BG's, i'm not a great believer of these caps.
Just as cerafines: sometimes they sound great as cathode-decoupling, sometimes its disastrous. Really don't know why:scratch:
 
#74
Re: Golden ears

Elso Kwak said:
Ok your ears are more "golden" than mines.
Must be my age.......
Click to expand...

we should introduce a new classification system
for diyaudio members ability to listen and hear more or less:

Audio Ears Ranking Scale
.............................................
1. Golden Ears - can hear anything, measurable or not, their ears never fail
2. Silvery Ears - can hear most anything, except for example difference between $2000 and $500 wire
3. Copper Ears - can hear music, also sometimes detect hum in a bad power supply
4. Jolly Ears - can tell if CD-player is ON/OFF from listening to loudspeakers
5. Muddy Ears - can not tell if sound is from a car outside or stereo playing
6. Missing Ears - will notice you are trying to tell them something, if you scream into their ears
...............................................
😀
 
#78
Re: Re: Golden ears

lineup said:


we should introduce a new classification system
for diyaudio members ability to listen and hear more or less:

Audio Ears Ranking Scale
.............................................
1. Golden Ears - can hear anything, measurable or not, their ears never fail
2. Silvery Ears - can hear most anything, except for example difference between $2000 and $500 wire
3. Copper Ears - can hear music, also sometimes detect hum in a bad power supply
4. Jolly Ears - can tell if CD-player is ON/OFF from listening to loudspeakers
5. Muddy Ears - can not tell if sound is from a car outside or stereo playing
6. Missing Ears - will notice you are trying to tell them something, if you scream into their ears
...............................................
😀
Click to expand...


!. should be reclassified ... Wife / Girlfriend / Mother-in-Law's ears...
 
Status
Not open for further replies.
Top Bottom