Konnichiwa,
The way the TDA1541 works is to use a swiched set of current sources which in effect auto-calibrate the Chip. The thing was called dynamic element matching and is one of the things that make teh TDA1541 so interesting.
The switching invariably generates "glitch" current spikes, which need to be "smoothed out". The number 14 is related to the fact that each channel has 6 active switched current sources for the lowest 6 bits and seventh followed by a passive divider(multiemitter transistor, not R2R - another eason for the unique sound quality) for the remaining 10 upper bits. That requires 7 decoupling points per DAC, as the TDA1541 contains 2 it needs 14.
Hence the answer "Those are a part of the silicone design." is completely correct if terse.
Sayonara
roibm said:
roibm said:
The way the TDA1541 works is to use a swiched set of current sources which in effect auto-calibrate the Chip. The thing was called dynamic element matching and is one of the things that make teh TDA1541 so interesting.
The switching invariably generates "glitch" current spikes, which need to be "smoothed out". The number 14 is related to the fact that each channel has 6 active switched current sources for the lowest 6 bits and seventh followed by a passive divider(multiemitter transistor, not R2R - another eason for the unique sound quality) for the remaining 10 upper bits. That requires 7 decoupling points per DAC, as the TDA1541 contains 2 it needs 14.
Hence the answer "Those are a part of the silicone design." is completely correct if terse.
Sayonara
Re: Re: Why that many DECOU pins?
Peranders answer alone is trivial in the context of my question. I already knew they are used internally in some way, but I didn't know in what way.
Now, thanks to you, I understand it better. Do you happen to have a link to some internal details about this chip?
Arigatou
Kuei Yang Wang said:
Peranders answer alone is trivial in the context of my question. I already knew they are used internally in some way, but I didn't know in what way.
Now, thanks to you, I understand it better. Do you happen to have a link to some internal details about this chip?
Arigatou
Re: Re: Re: Why that many DECOU pins?
Konnichiwa,
No, my info comes from a large number of sheets from Philips from the early 80's showing the various technology behind the DAC and eventually the silicon layout down to individual transistor level. Highly interesting reading, but way too much to scan for me....
Sayonara
Konnichiwa,
roibm said:
No, my info comes from a large number of sheets from Philips from the early 80's showing the various technology behind the DAC and eventually the silicon layout down to individual transistor level. Highly interesting reading, but way too much to scan for me....
Sayonara
guytou said:
Marantz in cd94MKII uses Arcotronics R75.But i think that SMD used in the cheapest model like 40, 50, 60, are better to various wima etc....(better tolerance, less ESL, no RF..)
But my questions it's another: how we could know what is the lead's number (or exact pin number) for the MSB bits??
The MSB it's a "I" impulse, right? It's larger than others bit? It needs some special track inside the IC?
TXS
Ciao
RR
riccardo said:
Riccardo,
Try here:- http://www.diyaudio.com/forums/showthread.php?postid=346623#post346623
Jean-Paul uses the same value on all pins.
I don't think it's necessary to use a larger cap there!
See here for info on how tda1541a DEM works :-
http://www.semiconductors.philips.com/acrobat_download/various/DIGITAL.pdf which details DEM!
From this to optmise tda1541a performance a good power supply (to supply Iref), and DEM reclocking is needed:-
http://www.diyaudio.com/forums/showthread.php?postid=370823#post370823
..tda1541a needs a stable 10v between -15v, and -5V but it's just a theory!
http://www.diyaudio.com/forums/showthread.php?postid=143055
Kind regards,
Ashley.
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