On Sun, 15 Sep 2013 11:53:45 -0700, Fred Abse <excretatauris@invalid.invalid> wrote:>On Sat, 14 Sep 2013 14:40:42 -0700, John Larkin wrote: > >> Mike tells me that the 1028N model wasn't accurate, > >Comparing the datasheet, and the models, I find that the >pinouts don't match, output on the wrong pin (5), should be 6. > >Small signal transient response of the LT1028 model shows far too much >overshoot, compared with datasheet waveform photograph, under stated >conditions, and looks much more like LT1128. > >Both using 10ns risetime test pulse. > >I assume that the datasheet is authoritative. The real device looks much nicer >than the model predicts. > >Not what we've come to expect from LTC. At least they came clean.There's no LT1028 (or LT1128) model in the latest release, probably going encrypted :-( ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Spice problem
Started by ●September 14, 2013
Reply by ●September 15, 20132013-09-15
Reply by ●September 15, 20132013-09-15
On 09/15/2013 02:53 PM, Fred Abse wrote:> On Sat, 14 Sep 2013 14:40:42 -0700, John Larkin wrote: > >> Mike tells me that the 1028N model wasn't accurate, > > Comparing the datasheet, and the models, I find that the > pinouts don't match, output on the wrong pin (5), should be 6. > > Small signal transient response of the LT1028 model shows far too much > overshoot, compared with datasheet waveform photograph, under stated > conditions, and looks much more like LT1128. > > Both using 10ns risetime test pulse. > > I assume that the datasheet is authoritative. The real device looks much nicer > than the model predicts. > > Not what we've come to expect from LTC. At least they came clean. >The LT1028 datasheet is a travesty. You'd never guess from the noise plot that there's a big noise peak at 300 kHz and another one (I'm told) out around 2 MHz. One of the more egregious bits of specsmanship I've seen--right up there with chopamp datasheets. I ripped them over it once, after discovering that nasty peak experimentally, and was told something along the lines of "Our marketing department decided that this was really an audio part, so the datasheet has all the data relevant to audio uses. Nobody cares about 300 kHz noise in audio." The audio noise level rose fairly dramatically at about that point. ;) 'The Hitchhiker's Guide to the Galaxy defines the Marketing Division of the Sirius Cybernetics Corporation as "A bunch of mindless jerks who will be the first against the wall when the revolution comes."' (Second against the wall will be the HR department, of course.) 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
Reply by ●September 15, 20132013-09-15
On Sun, 15 Sep 2013 12:51:45 -0700, Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:>On Sun, 15 Sep 2013 11:53:45 -0700, Fred Abse ><excretatauris@invalid.invalid> wrote: > >>On Sat, 14 Sep 2013 14:40:42 -0700, John Larkin wrote: >> >>> Mike tells me that the 1028N model wasn't accurate, >> >>Comparing the datasheet, and the models, I find that the >>pinouts don't match, output on the wrong pin (5), should be 6. >> >>Small signal transient response of the LT1028 model shows far too much >>overshoot, compared with datasheet waveform photograph, under stated >>conditions, and looks much more like LT1128. >> >>Both using 10ns risetime test pulse. >> >>I assume that the datasheet is authoritative. The real device looks much nicer >>than the model predicts. >> >>Not what we've come to expect from LTC. At least they came clean. > >There's no LT1028 (or LT1128) model in the latest release, probably >going encrypted :-( > > ...Jim ThompsonI did a full delete/reinstall of LT Spice yesterday, and it has three LT1028 versions in the "opamps" library. And one 1128. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Reply by ●September 15, 20132013-09-15
On Sun, 15 Sep 2013 15:52:53 -0400, Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>On 09/15/2013 02:53 PM, Fred Abse wrote: >> On Sat, 14 Sep 2013 14:40:42 -0700, John Larkin wrote: >> >>> Mike tells me that the 1028N model wasn't accurate, >> >> Comparing the datasheet, and the models, I find that the >> pinouts don't match, output on the wrong pin (5), should be 6. >> >> Small signal transient response of the LT1028 model shows far too much >> overshoot, compared with datasheet waveform photograph, under stated >> conditions, and looks much more like LT1128. >> >> Both using 10ns risetime test pulse. >> >> I assume that the datasheet is authoritative. The real device looks much nicer >> than the model predicts. >> >> Not what we've come to expect from LTC. At least they came clean. >> > >The LT1028 datasheet is a travesty. You'd never guess from the noise >plot that there's a big noise peak at 300 kHz and another one (I'm told) >out around 2 MHz. One of the more egregious bits of specsmanship I've >seen--right up there with chopamp datasheets. I ripped them over it >once, after discovering that nasty peak experimentally, and was told >something along the lines of > >"Our marketing department decided that this was really an audio part, so >the datasheet has all the data relevant to audio uses. Nobody cares >about 300 kHz noise in audio." > >The audio noise level rose fairly dramatically at about that point. ;) > >'The Hitchhiker's Guide to the Galaxy defines the Marketing Division of >the Sirius Cybernetics Corporation as "A bunch of mindless jerks who >will be the first against the wall when the revolution comes."' > >(Second against the wall will be the HR department, of course.) > >Cheers > >Phil HobbsI've used LT1028s in NMR gradient drivers, but bandwidth there is usually in the 30 KHz range. Got lucky, I guess. Funny how IC people leave bugs around forever; they rarely fix things, and often deny the problems. I'm sure there are cases where hundreds of users found the same bug, over many years, at great expense. -- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
Reply by ●September 15, 20132013-09-15
On Sun, 15 Sep 2013 13:30:52 -0700, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:>On Sun, 15 Sep 2013 12:51:45 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Sun, 15 Sep 2013 11:53:45 -0700, Fred Abse >><excretatauris@invalid.invalid> wrote: >> >>>On Sat, 14 Sep 2013 14:40:42 -0700, John Larkin wrote: >>> >>>> Mike tells me that the 1028N model wasn't accurate, >>> >>>Comparing the datasheet, and the models, I find that the >>>pinouts don't match, output on the wrong pin (5), should be 6. >>> >>>Small signal transient response of the LT1028 model shows far too much >>>overshoot, compared with datasheet waveform photograph, under stated >>>conditions, and looks much more like LT1128. >>> >>>Both using 10ns risetime test pulse. >>> >>>I assume that the datasheet is authoritative. The real device looks much nicer >>>than the model predicts. >>> >>>Not what we've come to expect from LTC. At least they came clean. >> >>There's no LT1028 (or LT1128) model in the latest release, probably >>going encrypted :-( >> >> ...Jim Thompson > >I did a full delete/reinstall of LT Spice yesterday, and it has three LT1028 >versions in the "opamps" library. And one 1128.I did an "update" two days ago, I'll try again. Thanks for the tip. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●September 15, 20132013-09-15
On Sun, 15 Sep 2013 13:30:52 -0700, John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:>On Sun, 15 Sep 2013 12:51:45 -0700, Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote: > >>On Sun, 15 Sep 2013 11:53:45 -0700, Fred Abse >><excretatauris@invalid.invalid> wrote: >> >>>On Sat, 14 Sep 2013 14:40:42 -0700, John Larkin wrote: >>> >>>> Mike tells me that the 1028N model wasn't accurate, >>> >>>Comparing the datasheet, and the models, I find that the >>>pinouts don't match, output on the wrong pin (5), should be 6. >>> >>>Small signal transient response of the LT1028 model shows far too much >>>overshoot, compared with datasheet waveform photograph, under stated >>>conditions, and looks much more like LT1128. >>> >>>Both using 10ns risetime test pulse. >>> >>>I assume that the datasheet is authoritative. The real device looks much nicer >>>than the model predicts. >>> >>>Not what we've come to expect from LTC. At least they came clean. >> >>There's no LT1028 (or LT1128) model in the latest release, probably >>going encrypted :-( >> >> ...Jim Thompson > >I did a full delete/reinstall of LT Spice yesterday, and it has three LT1028 >versions in the "opamps" library. And one 1128.Found it. Screwed up the date setting in my search engine :-( It's virtually 100% behavioral, plus a whole pile of "noiseless" resistors. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
