| General > General Technical Chat |
| Chips with built-in RFI protection |
| (1/6) > >> |
| mawyatt:
Noticed that some precision op-amps are stating they have some level of RFI built-in suppression. How widespread is this with newer chip designs? Best, |
| magic:
Seems that no one knows or cares :-// I have noticed that TI is making a big deal of it and datasheets of their newer opamps for industrial market (and some audio too, like OPA1656) show plots of "EMIRR". NE5534 had some distributed capacitance over input stage collector load resistors 45 years ago; not sure what other purpose that could serve given the high RC corner. |
| 2N3055:
You noticed right, I also see this being marketed lately a lot, even for bog standard parts like TL071 where TI has new "improved" series TL07XH that claim " High ESD (1.5 kV, HBM), integrated EMI and RF filters"... I was actually thinking of ordering some to see what it actually means, because datasheet doesn't specify a single number to that regard, except ESD resilience. No mention what EMI and RF filters do, what are the characteristics or how it was measured and how can be verified.. Is it RF filters in signal path? Is improved PSRR on power inputs? What ? But it has a typo where unity-gain bandwidth became "Utility-gain bandwidth" in some tables ... :-DD In layman terms, if that means that bass guitar amplifier will be more resilient to those pulses you get when you put your GSM phone nearby, just by changing out old TL071 to new TL071H that would be great. But it won't. That is all about circuit and layout of the components, grounding and shielding. So I really don't know what they mean by it. |
| T3sl4co1l:
I don't have anything quantitative to contribute, I've just noticed it in a few parts. It does indeed appear effective against input rectification, particularly at the high frequencies where the attenuation is strong. Most do not plot attenuation/immunity unfortunately; perhaps the same structures are used for all parts (why not copy-paste them, right?) and we can assume typical response? --- Quote from: 2N3055 on August 25, 2021, 07:28:19 am ---In layman terms, if that means that bass guitar amplifier will be more resilient to those pulses you get when you put your GSM phone nearby, just by changing out old TL071 to new TL071H that would be great. But it won't. That is all about circuit and layout of the components, grounding and shielding. --- End quote --- It will! Immunity certainly depends on all those things, but it is the product of all factors together, and dropping one of them by a solid 20dB or greater is an unambiguous win. Not bad for not having to rev the PCB. You do need it in all low-level signal paths, and you do need to avoid unfiltered signals into discrete semiconductor junctions, which might not be so easily managed in guitar pedals/amps specifically. But at least you aren't being held back by the overabundance of RF-susceptible ICs, and on-board filtering and grounding can be relaxed to a certain extent. Tim |
| magic:
They define it as a sort of immunity to amplitude demodulation of out-of-band RF. https://www.ti.com/lit/pdf/sboa128 That being said, given how laconic the TL07xH spec is, I'm not sure if it really was tested for "EMIRR" or "EMIRR IN+" by their own nomenclature... Also, no specification is given on the old part for comparison purposes. Good question to ask their tech support :P I wanted to tear one down but they aren't very widely available yet. edit Is it just me or is the new part really a flicker noise monster with twice the amplitude and corner at several kHz? Are they even serious? :wtf: --- Quote ---TL07xx Low-Noise FET-Input Operational Amplifiers --- End quote --- Fuck. Now that's starting to look like they have rebranded one of their CMOS opamps. Note the lack of J in front of FET. This cannot be real :scared: |
| Navigation |
| Message Index |
| Next page |