Influence of PS on clock modules

[Guido Tent]

[QUOTE]Originally posted by fmak
[B]

Originally posted by Elso Kwak


Fmak,
Are you referring to this circuit by Cuno Snoeren?
http://www1.tip.nl/~t708955/schem/xoschema.jpg

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Yes, also the TL431 Current Regulator configuration. Same order of noise reduction refers.

Hi Fred

Did you (or others) by any chance measure the output noise of that circuit ?

best regards

[fmak]

Originally posted by Guido Tent


Hi Fred

Did you (or others) by any chance measure the output noise of that circuit ?

best regards

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Yes, in situ in SACD player with supply from 12V regulator; I can get down to about 60 uV with OSCons across LM431, input, and output. I think some of the noise is coming thru' the 7812; really needs separate ps. The player I put this in has a very noisy digital section and power supply.

Guido, have you processed my order yet? Please send an email.

Fred

[Guido Tent]

Originally posted by fmak

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Yes, in situ in SACD player with supply from 12V regulator; I can get down to about 60 uV with OSCons across LM431, input, and output. I think some of the noise is coming thru' the 7812; really needs separate ps. The player I put this in has a very noisy digital section and power supply.

Guido, have you processed my order yet? Please send an email.

Fred

Hi Fred

What is the measurement bandwidth of your instrument ? If it is "infinite", 60 uV is not that bad ......

I will ship tomorrow, I visit he postoffice once a week otherwise It will cot me too much time (people queuing all the time)

best regards

[Guido Tent]

Originally posted by fmak

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Yes, in situ in SACD player with supply from 12V regulator; I can get down to about 60 uV with OSCons across LM431, input, and output. I think some of the noise is coming thru' the 7812; really needs separate ps. The player I put this in has a very noisy digital section and power supply.

Guido, have you processed my order yet? Please send an email.

Fred

Hi Fred

Bye the way: What is the regulator noise when not in the circuit ?

[fmak]

Hi Fred

Bye the way: What is the regulator noise when not in the circuit ? [/B][/QUOTE]
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Guido

Not in circuit, around 30 uV. Bandwidth 1MHz, Trio ac voltmeter, unweighted.

[Guido Tent]

Originally posted by fmak
Hi Fred

Bye the way: What is the regulator noise when not in the circuit ?

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Guido

Not in circuit, around 30 uV. Bandwidth 1MHz, Trio ac voltmeter, unweighted. [/B][/QUOTE]

Hi Fred

Calculation done in my head: That is about 30nV/Sqrrt Hz, not bad !

regards

[fmak]

Originally posted by Guido Tent

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Guido

Not in circuit, around 30 uV. Bandwidth 1MHz, Trio ac voltmeter, unweighted.

Hi Fred

Calculation done in my head: That is about 30nV/Sqrrt Hz, not bad !
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Guido

This took quite a lot of effort; not just connecting up ps to a regulator, and adjustments of decoupling in situ.

Silencing the SACD player (Sony SCDXB940) took much greater effort. I have never seen so many inductors built into the design which unfortunately have multiple grounds and long cable runs to the ps.

Fred

[Jesús Puerto]

Hii Guido Tent or .
Hola como estas.
Wiich is your opimion in these Graphics;


Jesús

[Guido Tent]

Originally posted by Jesús Puerto
Hii Guido Tent or .
Hola como estas.
Wiich is your opimion in these Graphics;


Jesús

Hola Jesús

Estoy bien (I am fine)

Just looked at the graphs. The PLL seems to put out a sine wave, which has more jitter as the input, so I would not use it.

What is the measurement time ? Any info on the spectral content of the distributed noise at the PLL output ?

best regards

[Fin]

Hi all

Originally posted by Guido Tent:-

Other problems can be taken away by removing the crosstalk to that same supply. For that reason it often helps to seperately supply all servo's (actuator, radial, focus and spindle) in the player, as they induce huge LF currents (Hz - kHz range) in the (often poorly designed) groundplanes.

What is the best way to achieve this?

1. Does one provide separate regulated supplies from the original transformer, for each servo?

OR

2. Does one use a separate transformer for the servo section?

OR

3. Does one use a separate transformer and power supplies for the sensitive stuff (DAC, analogue stage....) and leave the servos to be powered by the original transformer - with separated supplies?

OR

Something else??????


Regards

Fin