Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
i created this tabulation based on 2 app notes about noise (especially the eye opener for me, calculating 1Hz noise). by shuffling different supporting resistors, at the end, we find the usable signal over noise output. it really puts some insight into opamps that is used purely for current and...
thanks Klaus, in the case of the OPA140 where it operates in current mode, R3 is not series to produce EN2/ER2, but in parallel with the input. so in this case i assume EN2 = ER2 = parallel of source with the parallel R3? (= very low value i assume) ~~ am i right?
i see a few "nodes" of interest
1) fan draws air into heater, if fan fails, is there code for failsafe? ie : check fan is working?
2) if thermostat fails, is there another monitor to know the heat is not right?
@ about 16++A heater current, i have some experience that high current heater may...
Hello again edaboard veterans
i wish to understand, the math involved in comparing the voltage noise of these 2 opamp. (yes still learning to understand them). this time, i read this app sheet called SLYT237 from TI.
in OPA140 pdf, the voltage noise is simply given without reference to gain...
i have some time to look for more info, and i found this site.
http://dicks-website.eu/noisecalculator/index.html
i managed to plug in some numbers
i am not completely sure, but it seems like the OPA140 does perform better? can anyone have a look?
edit **
OPA140 values : Rs ~ 2.4M, 30C...
there is this which i roughly did to try and see where does the lower end noise could go as it is not on the PDF. does this make sense? esp the noise density convert to pp noise? (x sqrt of freq range? and x6.6 for peak peak?)
- - - Updated - - -
oh blind me, yes i see it now.
oh ops.
what if
gnd -- 68u -- 22R --\
gnd ----22R ------/
does this work?
on the other hand, i took a peek with LT1115 and AD797. it seem to make more sense now that a lower voltage density noise is needed as the input source impedance is so low that it will be negligible to create more...
when you say high pass roll off in feedback, i assume is this C6 ? just for sanity check, if R3+R6 ~ 220k and C6 = 68n ~~ the high pass in this case is 10.6Hz?
when you say cut-off extends far below actual, as in the 0.01Hz needs to be around 0.001? wow that needs very big capacitor.
i intend to design a LNA to find out the noise of batteries, zeners, low noise DC regulators. i think impedance under 10ohms.
your reply shed much light into my dis-array bits of thought, many thanks.
i am trying to take a peek into noise levels in the vicinity of 10 ~ 100nV, with x10000, this i...
im new here, but i seen some interesting DIY stuff
https://www.instructables.com/id/DIY-battery-tab-resistance-fine-spot-welder/
look at his cables, i think they are at least 10mm diameter to carry high current. some PCB design is normal, but they stack on top of the PCB track extra copper cable...
Hello n good day edaboard veterans,
i have many questions to ask to verify my curiosity into something i have been trying to play around in simulators, questions in other forums, etc etc, on low noise amplifier designing. (example this 1...
aha !
ok that resolves my suspicion that the multisim is also putting in these "errors"
but when i pull down the neg supply further beyond -1.2v ... the accuracy or linearity falls apart. what did i miss? an error loop going around neg rails to sense ladder?
i was simulating this scenario. it is a current sense. 1A = 1v final ratio
as with many sense packages available commercially, they do state that there is linearity problems in the low mA ranges.
so i went to try out some stuff in the old multisim
the question is, by introducing a small negative...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
