Lasse Langwadt Christensen wrote:> Den s�ndag den 13. oktober 2013 21.34.32 UTC+2 skrev John Larkin: >> Maxim makes an opamp, MAX44280, that has a specified input capacitance of 0.4 >> >> pF. That would be great in some apps where Cin causes noise-gain peaking. >> >> >> >> I figured I'd give Maxim another chance, after being s*****d by them in the >> >> past. >> >> >> >> So I went online and filled out their sample request. The process makes no >> >> sense, website runaround, but eventually I got it done. >> >> >> >> Two days later I got an email to the effect that the sample request was waiting >> >> for a product-line manager approval. I responded and asked why, and was told >> >> that it was standard internal procedure and would take only another 24 hours. >> >> >> >> OK, a week later I got two samples, packaged in a short tube and wrapped in a >> >> ball of sticky masking tape. >> >> >> >> These opamps, like most Maxim parts, have nonstandard pinout. I built a test >> >> fixture to measure Cin. With power off, I measured 1.4 pF on the non-inverting >> >> input pin. I powered it up and the opamp didn't act anything like an opamp. I >> >> checked everything three times and figured the amp was blown, so I tried to >> >> replace it. It's an SC70, really tiny, and my tweezers slipped and I pogoed it >> >> into the carpet, never to be seen again. >> >> >> >> The sales engineer emailed me to see how the samples were coming along, and I >> >> told him the situation. He promised to get me 10 more ASAP. Then he called back >> >> with a technical guy. I explained my setup. I'm using +-2.5 volt supplies, and >> >> the technical guy said that this is a single-supply opamp and might not be >> >> qualified for dual-supply operation. He said he'd contact the designers or >> >> something. I asked him how they defined and measured the 0.4 pF Cin, and he said >> >> he'd find out. They were due to call me last Monday. >> >> >> >> So far, no more parts, no call. >> >> > > it uses a magic hidden ground pin to tell if it single or dual supply? > > -LasseLike the virtual ground in the uA709..
Never Buy Maxim (again)
Started by ●October 13, 2013
Reply by ●October 14, 20132013-10-14
Reply by ●October 14, 20132013-10-14
John Larkin wrote:> On Sun, 13 Oct 2013 12:42:54 -0700 (PDT), bloggs.fredbloggs.fred@gmail.com > wrote: > >> On Sunday, October 13, 2013 3:34:32 PM UTC-4, John Larkin wrote: >>> Maxim makes an opamp, MAX44280, that has a specified input capacitance of 0.4 >>> >>> pF. That would be great in some apps where Cin causes noise-gain peaking. >>> >>> >>> >>> I figured I'd give Maxim another chance, after being s*****d by them in the >>> >>> past. >>> >>> >>> >>> So I went online and filled out their sample request. The process makes no >>> >>> sense, website runaround, but eventually I got it done. >>> >>> >>> >>> Two days later I got an email to the effect that the sample request was waiting >>> >>> for a product-line manager approval. I responded and asked why, and was told >>> >>> that it was standard internal procedure and would take only another 24 hours. >>> >>> >>> >>> OK, a week later I got two samples, packaged in a short tube and wrapped in a >>> >>> ball of sticky masking tape. >>> >>> >>> >>> These opamps, like most Maxim parts, have nonstandard pinout. I built a test >>> >>> fixture to measure Cin. With power off, I measured 1.4 pF on the non-inverting >>> >>> input pin. I powered it up and the opamp didn't act anything like an opamp. I >>> >>> checked everything three times and figured the amp was blown, so I tried to >>> >>> replace it. It's an SC70, really tiny, and my tweezers slipped and I pogoed it >>> >>> into the carpet, never to be seen again. >>> >>> >>> >>> The sales engineer emailed me to see how the samples were coming along, and I >>> >>> told him the situation. He promised to get me 10 more ASAP. Then he called back >>> >>> with a technical guy. I explained my setup. I'm using +-2.5 volt supplies, and >>> >>> the technical guy said that this is a single-supply opamp and might not be >>> >>> qualified for dual-supply operation. He said he'd contact the designers or >>> >>> something. I asked him how they defined and measured the 0.4 pF Cin, and he said >>> >>> he'd find out. They were due to call me last Monday. >>> >>> >>> >>> So far, no more parts, no call. >>> >>> >>> >>> >>> >>> -- >>> >>> >>> >>> 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 >> >> Maybe try something novel like buying them next time: >> http://www.mouser.com/Search/Refine.aspx?Keyword=MAX44280 > > And miss out on all that tech support? > >The floor you and they stand on is the support.
Reply by ●October 14, 20132013-10-14
On Sun, 13 Oct 2013 17:28:45 -0700, Spehro Pefhany <speffSNIP@interlogdotyou.knowwhat> wrote:> On Sun, 13 Oct 2013 13:08:03 -0700, the renowned John Larkin > <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote: > > >>> Maybe try something novel like buying them next time: >>> http://www.mouser.com/Search/Refine.aspx?Keyword=MAX44280 >> >> And miss out on all that tech support? > > They did inform you that you're trying to use a single-supply op-amp > on dual supplies. That kind of advice is hard to put a value on. > > > Best regards, > Spehro Pefhanynow THAT popped a stitch! typed with difficulty seeing through the tears of laughter.
Reply by ●October 14, 20132013-10-14
On 10/13/2013 12:34 PM, John Larkin wrote:> > These opamps, like most Maxim parts, have nonstandard pinout. I built a test > fixture to measure Cin. With power off, I measured 1.4 pF on the non-inverting > input pin.Who measures capacitance of a part that is powered down? Doh! There are diodes that need to be reverse biased ya know. Do you have someone who works for you that is, well you know, a competent electrical engineer? Perhaps you are not suited for electrical engineering. Have you considered software?
Reply by ●October 14, 20132013-10-14
On Mon, 14 Oct 2013 12:54:52 -0700, miso <miso@sushi.com> wrote:>On 10/13/2013 12:34 PM, John Larkin wrote: >> >> These opamps, like most Maxim parts, have nonstandard pinout. I built a test >> fixture to measure Cin. With power off, I measured 1.4 pF on the non-inverting >> input pin. >Who measures capacitance of a part that is powered down? Doh! There are >diodes that need to be reverse biased ya know.Of course, but I measured it first, powered down. Why not? It wouldn't work like an opamp closed-loop, and I need that to measure the powered-up capacitance.> >Do you have someone who works for you that is, well you know, a >competent electrical engineer? Perhaps you are not suited for electrical >engineering. Have you considered software?I've written a lot of code, but I prefer hardware design. All the things that I posted are true. Quit whining and show us some gear that you've designed... full of Maxim chips no doubt. -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Reply by ●October 14, 20132013-10-14
"miso" <miso@sushi.com> wrote in message news:l3hi8e$ql7$1@speranza.aioe.org...> On 10/13/2013 12:34 PM, John Larkin wrote: >> >> These opamps, like most Maxim parts, have nonstandard pinout. I built a >> test >> fixture to measure Cin. With power off, I measured 1.4 pF on the >> non-inverting >> input pin. > Who measures capacitance of a part that is powered down? Doh! There are > diodes that need to be reverse biased ya know. > > Do you have someone who works for you that is, well you know, a competent > electrical engineer? Perhaps you are not suited for electrical > engineering. Have you considered software? > > >It's called "characterizing the part". It is way beyond a libtard such as yourself to understand.
Reply by ●October 14, 20132013-10-14
On Mon, 14 Oct 2013 17:20:03 -0400, "tm" <No_one_home@white-house.gov> wrote:> >"miso" <miso@sushi.com> wrote in message >news:l3hi8e$ql7$1@speranza.aioe.org... >> On 10/13/2013 12:34 PM, John Larkin wrote: >>> >>> These opamps, like most Maxim parts, have nonstandard pinout. I built a >>> test >>> fixture to measure Cin. With power off, I measured 1.4 pF on the >>> non-inverting >>> input pin. >> Who measures capacitance of a part that is powered down? Doh! There are >> diodes that need to be reverse biased ya know. >> >> Do you have someone who works for you that is, well you know, a competent >> electrical engineer? Perhaps you are not suited for electrical >> engineering. Have you considered software? >> >> >> > >It's called "characterizing the part". It is way beyond a libtard such as >yourself to understand. >I'm curious about things like ESD capacitance. Given a test setup, why would anyone *not* want to measure the power-off capacitance, and then determine the C-V behavior? -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
Reply by ●October 14, 20132013-10-14
"John Larkin" <jlarkin@highlandtechnology.com> wrote in message news:8opo59hlf5nuv2547e8umkv42odgasum0l@4ax.com...> On Mon, 14 Oct 2013 17:20:03 -0400, "tm" <No_one_home@white-house.gov> > wrote: > >> >>"miso" <miso@sushi.com> wrote in message >>news:l3hi8e$ql7$1@speranza.aioe.org... >>> On 10/13/2013 12:34 PM, John Larkin wrote: >>>> >>>> These opamps, like most Maxim parts, have nonstandard pinout. I built a >>>> test >>>> fixture to measure Cin. With power off, I measured 1.4 pF on the >>>> non-inverting >>>> input pin. >>> Who measures capacitance of a part that is powered down? Doh! There are >>> diodes that need to be reverse biased ya know. >>> >>> Do you have someone who works for you that is, well you know, a >>> competent >>> electrical engineer? Perhaps you are not suited for electrical >>> engineering. Have you considered software? >>> >>> >>> >> >>It's called "characterizing the part". It is way beyond a libtard such as >>yourself to understand. >> > > I'm curious about things like ESD capacitance. Given a test setup, why > would anyone *not* want to measure the power-off capacitance, and then > determine the C-V behavior? > > > -- > > John Larkin Highland Technology, Inc > > jlarkin at highlandtechnology dot com > http://www.highlandtechnology.com > > Precision electronic instrumentation > Picosecond-resolution Digital Delay and Pulse generators > Custom laser drivers and controllers > Photonics and fiberoptic TTL data links > VME thermocouple, LVDT, synchro acquisition and simulationNot only that but why would you not want to know how the device might load some external circuit when it is in its powered down state. In battery operated devices, one may wish to power down an amplifier that is connected to some external operating device. Look, there is no use trying to explain anything to these libtards. They are incapable of being educated.
Reply by ●October 14, 20132013-10-14
Thats right! don't ever listen to a commielib. if they start talking, just punch them in the face. That's what the Duke does! Someday we'll get rid of all the lieberals and America will be #1 again! all liberals must die! Duke Stopcock On Monday, October 14, 2013 5:58:24 PM UTC-4, tm wrote:> "John Larkin" <jlarkin@highlandtechnology.com> wrote in message > > news:8opo59hlf5nuv2547e8umkv42odgasum0l@4ax.com... > > > On Mon, 14 Oct 2013 17:20:03 -0400, "tm" <No_one_home@white-house.gov> > > > wrote: > > > > > >> > > >>"miso" <miso@sushi.com> wrote in message > > >>news:l3hi8e$ql7$1@speranza.aioe.org... > > >>> On 10/13/2013 12:34 PM, John Larkin wrote: > > >>>> > > >>>> These opamps, like most Maxim parts, have nonstandard pinout. I built a > > >>>> test > > >>>> fixture to measure Cin. With power off, I measured 1.4 pF on the > > >>>> non-inverting > > >>>> input pin. > > >>> Who measures capacitance of a part that is powered down? Doh! There are > > >>> diodes that need to be reverse biased ya know. > > >>> > > >>> Do you have someone who works for you that is, well you know, a > > >>> competent > > >>> electrical engineer? Perhaps you are not suited for electrical > > >>> engineering. Have you considered software? > > >>> > > >>> > > >>> > > >> > > >>It's called "characterizing the part". It is way beyond a libtard such as > > >>yourself to understand. > > >> > > > > > > I'm curious about things like ESD capacitance. Given a test setup, why > > > would anyone *not* want to measure the power-off capacitance, and then > > > determine the C-V behavior? > > > > > > > > > -- > > > > > > John Larkin Highland Technology, Inc > > > > > > jlarkin at highlandtechnology dot com > > > http://www.highlandtechnology.com > > > > > > Precision electronic instrumentation > > > Picosecond-resolution Digital Delay and Pulse generators > > > Custom laser drivers and controllers > > > Photonics and fiberoptic TTL data links > > > VME thermocouple, LVDT, synchro acquisition and simulation > > > > Not only that but why would you not want to know how the device might load > > some external circuit when it is in its powered down state. In battery > > operated devices, one may wish to power down an amplifier that is connected > > to some external operating device. > > > > Look, there is no use trying to explain anything to these libtards. They are > > incapable of being educated.
Reply by ●October 14, 20132013-10-14
On Mon, 14 Oct 2013 15:29:44 -0700 (PDT), duke.stopcock@gmail.com wrote:>Thats right! don't ever listen to a commielib. if they start talking, just punch them in the face. That's what the Duke does! > >Someday we'll get rid of all the lieberals and America will be #1 again! > >all liberals must die! >Duke Stopcock > >There's no reason they should die. On the contrary, they should be kept well away from electronic instruments so they don't hurt themselves. -- John Larkin Highland Technology, Inc jlarkin at highlandtechnology dot com http://www.highlandtechnology.com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom laser drivers and controllers Photonics and fiberoptic TTL data links VME thermocouple, LVDT, synchro acquisition and simulation
