Where are intern. schematic of LME49710 LME49720 and LM4562 (LM 4562 LME 49710 49720)

tiefbassuebertr · 19th July 2009, 11:14 PM

Hi,
from many top class operational amps there are schematic diagrams at botton from the datasheets (e. g. AD797, see
http://www.diyaudio.com/forums/attac...amp=1167126984
For the newest LME series from National Semiconductor I don't find schematics by concerning datasheets. I find on other places a wide range of information sources e. g. about
Bob Pease on the New LM4562
National opamp inflation
but also no schematic diagrams of the internal structure. Who is the developer of the LME design?
Perhaps one of you can give me advice about download source of this one.
Thank you very much in advance.

P.S. The main reason for the high sonic quality of AD797 (by the way - also by Mr. Nelson Pass power amps from X-Series, basicly bridged AD797, main difference: MOSFETs and power follower output version) is the single voltage gain stage as differential folded cascode.
Is it the same reason also by the newest LME series`?

Enzo · 20th July 2009, 03:45 AM

Why don;t you contact National Semiconductor directly and ask them?

Gopher · 20th July 2009, 03:53 AM

There's no schematic because National don't want to tell their competitors how they've done it. Duh!

tiefbassuebertr · 30th October 2009, 06:00 PM

Quote:

Originally Posted by Gopher

There's no schematic because National don't want to tell their competitors how they've done it. Duh!

I have read this patent document:
Boliven Patents - US7071781: High speed, high resolution amplifier topology - Reader
And I do not rule out the possibility, that this could be the internal circuit

peranders · 30th October 2009, 06:21 PM

Most schematics are simplified. I'm sure Mr. Scott Wurcer can sign that since he has designed the AD797.

nelsonvandal · 30th October 2009, 07:30 PM

Don't you think it's some kind of complementary design, something like LM6171 with extras?

tiefbassuebertr · 3rd January 2010, 04:49 PM

also the topology could be basicly the internal circuit:

Wowozange · 20th January 2010, 07:07 PM

You can go to audiokharma and search the thread "National opamp inflation" where you will meet audioman54. He is the one you are searching for.

nelsonvandal · 21st January 2010, 02:30 PM

Quote:

Originally Posted by Wowozange

You can go to audiokharma and search the thread "National opamp inflation" where you will meet audioman54. He is the one you are searching for.

He's active here as well, but he doesn't give away any secrets. Not a hint.

tiefbassuebertr · 09:07 AM

Quote:

Originally Posted by nelsonvandal

He's active here as well, but he doesn't give away any secrets. Not a hint.

Interesting to know ! Please let me know his diyaudio member name to reading his threads (the "audioman54" here must be an other member than that one from
http://audiokarma.org/

19th July 2009, 11:14 PM	#1
tiefbassuebertr diyAudio Member Join Date: Jul 2005 Location: D-55629 Schwarzerden	Where are intern. schematic of LME49710 LME49720 and LM4562 (LM 4562 LME 49710 49720) Hi, from many top class operational amps there are schematic diagrams at botton from the datasheets (e. g. AD797, see http://www.diyaudio.com/forums/attac...amp=1167126984 For the newest LME series from National Semiconductor I don't find schematics by concerning datasheets. I find on other places a wide range of information sources e. g. about Bob Pease on the New LM4562 National opamp inflation but also no schematic diagrams of the internal structure. Who is the developer of the LME design? Perhaps one of you can give me advice about download source of this one. Thank you very much in advance. P.S. The main reason for the high sonic quality of AD797 (by the way - also by Mr. Nelson Pass power amps from X-Series, basicly bridged AD797, main difference: MOSFETs and power follower output version) is the single voltage gain stage as differential folded cascode. Is it the same reason also by the newest LME series`?

30th October 2009, 06:21 PM	#5
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	Most schematics are simplified. I'm sure Mr. Scott Wurcer can sign that since he has designed the AD797. __________________ /Per-Anders (my first name) or P-A as my friends call me

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
LME 49720 questions	Artie	Chip Amps	2	10th April 2009 08:31 PM
LME49720 Vs LM4562....	Ryssen	Chip Amps	16	1st July 2008 08:36 PM
Lm 4562	Pocoyo	Swap Meet	0	6th January 2008 12:14 AM
Lm 4562	Pocoyo	Group Buys	0	14th November 2007 07:27 AM
WANTED TO BUY - LM4562 or LME49720 8Pin DIP	arupg	Swap Meet	0	9th July 2007 07:57 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

20th July 2009, 03:45 AM	#2
Enzo diyAudio Member Join Date: Sep 2004 Location: Lansing, Michigan	Why don;t you contact National Semiconductor directly and ask them?

20th July 2009, 03:53 AM	#3
Gopher diyAudio Member Join Date: Nov 2005 Location: UK	There's no schematic because National don't want to tell their competitors how they've done it. Duh!

30th October 2009, 07:30 PM	#6
nelsonvandal diyAudio Member Join Date: Nov 2006	Don't you think it's some kind of complementary design, something like LM6171 with extras?

20th January 2010, 07:07 PM	#8
Wowozange diyAudio Member Join Date: Dec 2009	You can go to audiokharma and search the thread "National opamp inflation" where you will meet audioman54. He is the one you are searching for.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)