Forums

Where to get a simple datasheet? for LMF90

Started by RobertMacy January 27, 2014
This is a simple switched capacitor filter made by National. Would  
somebody send me a copy, or at least provide a URL that HAS it!!! and not  
datasheet or alldata crap!  If AppNote available that too please.

I just went through the most frustrating 45 minutes trying to get a simple  
!@#$#@!#$ data sheet! Google search shows 8,000+ pages of either alldata,  
or datasheet, ok so tried going to both, all I got there were ads for  
unrelated chips and ?? couldn't even tell, kept asking me to download a  
pdf viewer!! what?!

So thought I'd go to the source [which I usually do first] went to  
<http://www.national.com> which of course took me to <http://www.ti.com>  
because TI bought out National and TI's website is usually pretty easy to  
navigate so did a search for LMF90 only to come up with nothing found.

I'd like a URL ending in .pdf so I can click on it and select 'download  
the contents of the link', instead of going off to some jave infected  
website that either hangs, delays, my system or wants to give me videos,  
and no where in sight is a place to get a copy of the datasheet. Even the  
'view' data sheet resulted in nothing happening!! arrrggg! ...temporary  
end of rant.

So, anybody have a copy, or know a 'good' URL?
On Mon, 27 Jan 2014, RobertMacy wrote:

> This is a simple switched capacitor filter made by National. Would somebody > send me a copy, or at least provide a URL that HAS it!!! and not datasheet or > alldata crap! If AppNote available that too please. >
Have you got the part number right? National's first generation filter like that had some other prefix (I can't remember what, I'd know the minute I saw it). I'm thinking "MFC" but I don't know why. It didn't start with National's traditional prefix, "LM". Maybe later they used some other prefix, but I'd double check. Michael
> I just went through the most frustrating 45 minutes trying to get a simple > !@#$#@!#$ data sheet! Google search shows 8,000+ pages of either alldata, or > datasheet, ok so tried going to both, all I got there were ads for unrelated > chips and ?? couldn't even tell, kept asking me to download a pdf viewer!! > what?! > > So thought I'd go to the source [which I usually do first] went to > <http://www.national.com> which of course took me to <http://www.ti.com> > because TI bought out National and TI's website is usually pretty easy to > navigate so did a search for LMF90 only to come up with nothing found. > > I'd like a URL ending in .pdf so I can click on it and select 'download the > contents of the link', instead of going off to some jave infected website > that either hangs, delays, my system or wants to give me videos, and no where > in sight is a place to get a copy of the datasheet. Even the 'view' data > sheet resulted in nothing happening!! arrrggg! ...temporary end of rant. > > So, anybody have a copy, or know a 'good' URL?
On 27.1.14 17:02, RobertMacy wrote:
> This is a simple switched capacitor filter made by National. Would > somebody send me a copy, or at least provide a URL that HAS it!!! and > not datasheet or alldata crap! If AppNote available that too please. > > I just went through the most frustrating 45 minutes trying to get a > simple !@#$#@!#$ data sheet! Google search shows 8,000+ pages of either > alldata, or datasheet, ok so tried going to both, all I got there were > ads for unrelated chips and ?? couldn't even tell, kept asking me to > download a pdf viewer!! what?! > > So thought I'd go to the source [which I usually do first] went to > <http://www.national.com> which of course took me to <http://www.ti.com> > because TI bought out National and TI's website is usually pretty easy > to navigate so did a search for LMF90 only to come up with nothing found. > > I'd like a URL ending in .pdf so I can click on it and select 'download > the contents of the link', instead of going off to some jave infected > website that either hangs, delays, my system or wants to give me videos, > and no where in sight is a place to get a copy of the datasheet. Even > the 'view' data sheet resulted in nothing happening!! arrrggg! > ...temporary end of rant. > > So, anybody have a copy, or know a 'good' URL?
Just got a copy from: <http://doc.chipfind.ru/nsc/lmf90.htm>. -- Tauno Voipio
On Mon, 27 Jan 2014 08:26:10 -0700, Tauno Voipio  
<tauno.voipio@notused.fi.invalid> wrote:

>> ...snip... > Just got a copy from: > <http://doc.chipfind.ru/nsc/lmf90.htm>. >
THANK YOU !!!! At first I couldn't figure out the significance of the giant offer to download a spec for a PIC, but below that was indeed a URL that yielded the .pdf ending so I could download. Got it thanks ...now any AppNotes floating around?
On Mon, 27 Jan 2014 10:18:27 -0500, Michael Black <et472@ncf.ca> wrote:

>On Mon, 27 Jan 2014, RobertMacy wrote: > >> This is a simple switched capacitor filter made by National. Would somebody >> send me a copy, or at least provide a URL that HAS it!!! and not datasheet or >> alldata crap! If AppNote available that too please. >> >Have you got the part number right? National's first generation filter >like that had some other prefix (I can't remember what, I'd know the minute I >saw it). I'm thinking "MFC" but I don't know why. It didn't start >with National's traditional prefix, "LM". Maybe later they used some other >prefix, but I'd double check.
National's classic switched-cap filter was the MF10, metal-gate CMOS. There was a later poly-gate version, can't remember the part number. Overall, switched-cap filters weren't all that great. OK for some apps, but they were really noisy, and aliased anything available, including power supply crud. I once designed a double-conversion superhet FSK modem full of MF10s, for Reuters' landline newswire service. Sold a few before PCs and the Internet made the classic newswire thing obsolete. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation
On 01/27/2014 11:27 AM, John Larkin wrote:
> On Mon, 27 Jan 2014 10:18:27 -0500, Michael Black <et472@ncf.ca> wrote: > >> On Mon, 27 Jan 2014, RobertMacy wrote: >> >>> This is a simple switched capacitor filter made by National. Would somebody >>> send me a copy, or at least provide a URL that HAS it!!! and not datasheet or >>> alldata crap! If AppNote available that too please. >>> >> Have you got the part number right? National's first generation filter >> like that had some other prefix (I can't remember what, I'd know the minute I >> saw it). I'm thinking "MFC" but I don't know why. It didn't start >> with National's traditional prefix, "LM". Maybe later they used some other >> prefix, but I'd double check. > > National's classic switched-cap filter was the MF10, metal-gate CMOS. There was > a later poly-gate version, can't remember the part number. >
The LMF100. Nice part if you needed to do anything fancy and low SNR was okay. I used it to make a SSB mixer once, and it worked great.
> Overall, switched-cap filters weren't all that great. OK for some apps, but they > were really noisy, and aliased anything available, including power supply crud. > > I once designed a double-conversion superhet FSK modem full of MF10s, for > Reuters' landline newswire service. Sold a few before PCs and the Internet made > the classic newswire thing obsolete.
The clock-tunable thing was pretty convenient for some jobs, especially back when tight-tolerance capacitors were expensive. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
On Mon, 27 Jan 2014 11:30:37 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>On 01/27/2014 11:27 AM, John Larkin wrote: >> On Mon, 27 Jan 2014 10:18:27 -0500, Michael Black <et472@ncf.ca> wrote: >> >>> On Mon, 27 Jan 2014, RobertMacy wrote: >>> >>>> This is a simple switched capacitor filter made by National. Would somebody >>>> send me a copy, or at least provide a URL that HAS it!!! and not datasheet or >>>> alldata crap! If AppNote available that too please. >>>> >>> Have you got the part number right? National's first generation filter >>> like that had some other prefix (I can't remember what, I'd know the minute I >>> saw it). I'm thinking "MFC" but I don't know why. It didn't start >>> with National's traditional prefix, "LM". Maybe later they used some other >>> prefix, but I'd double check. >> >> National's classic switched-cap filter was the MF10, metal-gate CMOS. There was >> a later poly-gate version, can't remember the part number. >> > >The LMF100. Nice part if you needed to do anything fancy and low SNR >was okay. I used it to make a SSB mixer once, and it worked great. > >> Overall, switched-cap filters weren't all that great. OK for some apps, but they >> were really noisy, and aliased anything available, including power supply crud. >> >> I once designed a double-conversion superhet FSK modem full of MF10s, for >> Reuters' landline newswire service. Sold a few before PCs and the Internet made >> the classic newswire thing obsolete. > >The clock-tunable thing was pretty convenient for some jobs, especially >back when tight-tolerance capacitors were expensive. >
Yeah, the modem did any channel, and any one of three baud rate/bandwidths, with just dip switches. The older stuff had plug-in LC filters. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation
On 01/27/2014 10:02 AM, RobertMacy wrote:
> This is a simple switched capacitor filter made by National. Would > somebody send me a copy, or at least provide a URL that HAS it!!! and > not datasheet or alldata crap! If AppNote available that too please. > > I just went through the most frustrating 45 minutes trying to get a > simple !@#$#@!#$ data sheet! Google search shows 8,000+ pages of either > alldata, or datasheet, ok so tried going to both, all I got there were > ads for unrelated chips and ?? couldn't even tell, kept asking me to > download a pdf viewer!! what?! > > So thought I'd go to the source [which I usually do first] went to > <http://www.national.com> which of course took me to <http://www.ti.com> > because TI bought out National and TI's website is usually pretty easy > to navigate so did a search for LMF90 only to come up with nothing found. > > I'd like a URL ending in .pdf so I can click on it and select 'download > the contents of the link', instead of going off to some jave infected > website that either hangs, delays, my system or wants to give me videos, > and no where in sight is a place to get a copy of the datasheet. Even > the 'view' data sheet resulted in nothing happening!! arrrggg! > ...temporary end of rant. > > So, anybody have a copy, or know a 'good' URL?
The app note mentioning the LMF90 was AN779, but they edited it out of AN 779A. The old version is at http://www.swarthmore.edu/NatSci/echeeve1/Ref/DataSheet/IntroToFilters.pdf Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
On 01/27/2014 10:02 AM, RobertMacy wrote:
> This is a simple switched capacitor filter made by National. Would > somebody send me a copy, or at least provide a URL that HAS it!!! and > not datasheet or alldata crap! If AppNote available that too please. > > I just went through the most frustrating 45 minutes trying to get a > simple !@#$#@!#$ data sheet! Google search shows 8,000+ pages of either > alldata, or datasheet, ok so tried going to both, all I got there were > ads for unrelated chips and ?? couldn't even tell, kept asking me to > download a pdf viewer!! what?! > > So thought I'd go to the source [which I usually do first] went to > <http://www.national.com> which of course took me to <http://www.ti.com> > because TI bought out National and TI's website is usually pretty easy > to navigate so did a search for LMF90 only to come up with nothing found. > > I'd like a URL ending in .pdf so I can click on it and select 'download > the contents of the link', instead of going off to some jave infected > website that either hangs, delays, my system or wants to give me videos, > and no where in sight is a place to get a copy of the datasheet. Even > the 'view' data sheet resulted in nothing happening!! arrrggg! > ...temporary end of rant. > > So, anybody have a copy, or know a 'good' URL?
And there's a real datasheet at http://www.datasheetarchive.com/dlmain/Datasheets-22/DSA-424155.pdf Since the parasites have taken over the search engine ecosystem, Datasheetarchive's built-in search works better than using Google to search DSA. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
On Monday, January 27, 2014 10:02:10 AM UTC-5, Robert Macy wrote:
> This is a simple switched capacitor filter made by National. Would > > somebody send me a copy, or at least provide a URL that HAS it!!! and not > > datasheet or alldata crap! If AppNote available that too please. > > > > I just went through the most frustrating 45 minutes trying to get a simple > > !@#$#@!#$ data sheet! Google search shows 8,000+ pages of either alldata, > > or datasheet, ok so tried going to both, all I got there were ads for > > unrelated chips and ?? couldn't even tell, kept asking me to download a > > pdf viewer!! what?! > > > > So thought I'd go to the source [which I usually do first] went to > > <http://www.national.com> which of course took me to <http://www.ti.com> > > because TI bought out National and TI's website is usually pretty easy to > > navigate so did a search for LMF90 only to come up with nothing found. > > > > I'd like a URL ending in .pdf so I can click on it and select 'download > > the contents of the link', instead of going off to some jave infected > > website that either hangs, delays, my system or wants to give me videos, > > and no where in sight is a place to get a copy of the datasheet. Even the > > 'view' data sheet resulted in nothing happening!! arrrggg! ...temporary > > end of rant. > > > > So, anybody have a copy, or know a 'good' URL?
This one was one of the first in a google search: http://www.ic-on-line.cn/view_download.php?id=1590752&file=0296%5Clmf90_1398788.pdf Even has listing for brokers still selling it. Google search terms "LMF90 switched capacitor datasheet" and it went straight to it.