hybridfree/eevblog-posts huggingface dataset:
Difference between Semtech GV7601 and GS2971 (3G-SDI receivers) - Page 1
Forum section: electronics / projects

author: Yansi
author_rank: Super Contributor
timestamp: December 16, 2020, 11:03:30 am
content: Hello,just a quick question, I can't really answer myself right now, as I probably don't see the forest for the trees: What the heck is tha main difference in between the SemtechGV7601andGS29713G-SDI receivers?Both devices appear to have the same functionality, same package and pinout, even same power consumption. So what the hell is going on in there?Apart from that the GV7601 listed on Mouser as "obsolete", I couldn't spot a difference.Thanks for pointing me at the right direction!Y.
difference between the KP10-15 and KPF10-15 launcher?? - Page 1
Forum section: electronics / projects

author: katieLi
author_rank: Newbie
timestamp: March 23, 2020, 01:21:09 pm
content: Is there a difference between the KP10-15 and KPF10-15 launcher? Can I replace a KPF10-15 launcher with a KP10-15 launcher and not degrade the performance? Thank you so much!!!
Difference load cell & strain gauge / Basic question of strain - Page 1
Forum section: electronics / projects

author: A2
author_rank: Contributor
timestamp: March 25, 2014, 08:26:52 am
content: Is there any difference between strain gauge & load cell.Load cell datasheet:http://www.meas-spec.com/downloads/FC23.pdfstrain data:http://www.omega.com/techref/pdf/STR...NICAL_DATA.pdfIf we look at datsheet of load cell it exactly says that at full rated load voltage will be 100mV. Full rated load is given exactly.1. Strain gauge datasheet mentions only strain like 50000 micrstrain. How can I convert it into weight. What's is the weight when strain is 5000, 10000, microstrian. What is max weight in kg when 50000 microstrain occurs.2. When we connect strain gauge in quarter bridge it gives output in change in voltage when strain gauge resistance change. Let say on 1 ohm change voltage change to 1mV. Now how to convert it into load in microcontroller code. I connect 5V to wheatstone.

author: han
author_rank: Frequent Contributor
timestamp: March 25, 2014, 08:50:38 am
content: strain gauge = resistance change depend on stressload cell = strain gauge mounted in metal, so mechanical stress is propotional to force

author: han
author_rank: Frequent Contributor
timestamp: March 25, 2014, 08:53:04 am
content: for Signal conditioning and 24 bit ADC Use NAU7802KGI (very cheap)
differences between MAX3096 and MAX3094 - Page 1
Forum section: electronics / projects

author: JoelStienlet
author_rank: Newbie
timestamp: September 21, 2019, 02:28:37 pm
content: Hello everybody,I don't see many differences between the MAX3096 and MAX3094, except the enable logic, on the max3096 all four receivers are enabled/disabled at the same time, whereas on the max3094 they're grouped in two pairs. But except this I can't spot any major difference. I find it strange that Maxim published two separate datasheets for such very similar devices! So I thought, perhaps there is another difference that I missed?Thank you!
Help needed: Differences between Sony Microdisplays ECX334AF and ECX336C - Page 1
Forum section: electronics / projects

author: david072
author_rank: Newbie
timestamp: October 10, 2025, 08:33:48 pm
content: Hello everyone, I'm working on a device with a Head-Up Display and I'm trying to figure out the best way to handle the optics. I found the following product that integrates a fairly high resolution OLED Microdisplay with resin optics which should be the smallest way of realising the optics for the HUD:https://www.aliexpress.us/item/3256809089945545.htmlThe linked product uses the ECX336CN Display from Sony (overview of the "ECX33" family here:https://www.sony-semicon.com/en/products/microdisplay/oled.html). Since I want the device to be as small as possible, I would like to design a custom PCB that directly interfaces with the display's FPC connector. However, that would require me to know the pinout of the display and Sony refuses to talk to me because I'm not a business.My best lead is this topichttps://www.eevblog.com/forum/projects/need-help-replace-evf-micro-oled-with-a-big-one/msg3820730/#msg3820730, where someone posted the datasheet of a similar variant, the ECX334AF.Does anyone know whether these displays have differences in their pinout and point me to them? Any help would be greatly appreciated as I was not able to find the datasheet/pinout for any other of the "ECX33" display variants.
Differences between TIP35C and TIP35CW - Page 1
Forum section: electronics / projects

author: icesoft
author_rank: Newbie
timestamp: November 11, 2013, 02:33:31 pm
content: I'm repairing a servo drive on one of our machines here at work, and Mouser shows they're out of ST branded TIP35C's (until January), but they have TIP35CW's, this drive also uses TIP36C's as well in the other half of the H-bridge, so I would be buying the matching complement as well. Just want to know what difference the 'W' suffix makes in the part and if it would make enough difference for my application.I'm already ordering a bunch of other stuff from Mouser, and don't want to make another order through Digikey for the transistors if I can help it.

author: minime72706
author_rank: Frequent Contributor
timestamp: November 11, 2013, 09:49:12 pm
content: A bit of research shows that they appear to be identical. The datasheets are effectively identical except for different change logs and revision numbers. I'm thinking that TO-218 and TO-247 versions existed with different part numbers in the past, but now everything is being moved over to TO-247.

author: wraper
author_rank: Unknown
timestamp: November 11, 2013, 09:54:21 pm
content: Quote from: minime72706 on November 11, 2013, 09:49:12 pmRev 4 (2008) of ST datasheet for TIP35C changed package from TO-218 and TO-247. TIP35CW was in TO-247 from the beginning. ON discontinues TIP35C in TO-218 and will make only TIP35CG in TO-247.

author: dannyf
author_rank: Super Contributor
timestamp: November 11, 2013, 10:36:25 pm
content: It is hard to be definitive without looking at the manufacturer's datasheet.

author: icesoft
author_rank: Newbie
timestamp: November 12, 2013, 05:59:01 pm
content: Thanks minime and wraper, I was wondering if that was the case.
Differences between USB Controller Chips - Page 1
Forum section: electronics / projects

author: prwiley
author_rank: Contributor
timestamp: January 03, 2022, 02:40:25 pm
content: I am working on a project that uses a Raspberry Pi and a number of usb audio devices to do audio playback as described here:https://www.esologic.com/multi-audio/I am using a Raspberry Pi 4 B 4GB and three of these audio devices:https://www.aliexpress.com/item/4000226869404.html?spm=a2g0o.9042311.0.0.51c14c4dH2a235As in the example project cited, I have a Python script that uses threading to perform playback through multiple devices at the same time via the sounddevice library (https://python-sounddevice.readthedocs.io/en/0.3.12/api.html).Trough experiment I have found that I get different results depending on the controller chip in the USB hub.When a hub with a Realtek RTS5401 controller chip (https://datasheetspdf.com/datasheet/RTS5401.html) is used there is no audio distortion when more one device is playing audio. It works as wanted and expected.When a hub with a Genesys Logic GL3510 controller chip (can't find datasheet) is used audio playback through two or three devices at the same time is distorted. It is scratchy and unintelligible.Both hubs are powered with their own power supply independent of the RPi. The Realtek device is INSIGNIA brand from BestBuy. The Genesys device comes from USBGear (https://www.usbgear.com/CG-3510S4-Board.html)The question I have is what is difference between the hubs/chips that might account for the difference in audio quality. The possible engineering issues are outside my experience and expertise, but I am curious to know what they might be.Thanks in advance for any observations/explanations/ideas.
differences with SO-DIMM200 sockets- quality  / harsh environment etc??? - Page 1
Forum section: electronics / projects

author: glenenglish
author_rank: Frequent Contributor
timestamp: April 04, 2025, 10:11:08 pm
content: I'm considering using a module that comes on a SO-DIMM200 socket. any comments if they are good or bad for LF vibration ? The test data in the datssheets suggests they're OK for moderate vib.any general comments on any bad experiences of using these (for non memory) ?right angle mount on PCB......Looking at Mouser search results , there are 20 different connectors, spanning $3 to $30 from the same Vendor - TE)but no differences in the drill-down columns....Hmm ....... searching on Digikey,maybe they have more columns in the search...---- ok so some have board guides, some just latches. and some accomodate 'upside down' ... and there are different heights, presumably to accomodate different thickness modules..glen
Different bandwidths for DIP vs SOIC (AD8001) - Page 1
Forum section: electronics / projects

author: PartialDischarge
author_rank: Super Contributor
timestamp: December 12, 2019, 10:39:11 am
content: What is the rationale behind such big difference in the bandwidth of a PDIP vs SOIC packages in the AD8001?This being a current op-amp I can only think of the capacitance in the negative feedback terminal to be higher in the DIP package, thus its bandwidth, but I'm not sure if there are other factors.https://www.analog.com/media/en/technical-documentation/data-sheets/AD8001.pdf

author: dzseki
author_rank: Frequent Contributor
timestamp: December 12, 2019, 10:47:43 am
content: Pins of the SOIC package are inherently much closer to eachother leading to more stray capacitance between the terminals, here the inverting IN and the output pins are the most concern.

author: Kleinstein
author_rank: Super Contributor
timestamp: December 12, 2019, 12:18:28 pm
content: In the smaller package the pins are closer to each other, but the lenght and area is also smaller. With a coax cable the capacitance per unit length only depends on the dielectric and the ratio of inner to outer diameter, not that absolute scale. So though much smaller distance a thin cable of same ratio would have the same capacitance per lenght. A similar scaling should apply to a scaled down leed-frame: similar capacitance per unit length and thus less capacitance for the smaller version.Similar parasitic inductance can be smaller for the smaller case version.It is already odd to find such a fast amplifier in the large DIP case.

author: Berni
author_rank: Super Contributor
timestamp: December 12, 2019, 12:29:56 pm
content: This is 500MHz we are talking about.Picofarads matter a lot at these frequencies. Just 1 pF of capacitance can cause the same flow of current that a 300 Ohm resistor would pass.So all the extra size of the DIP pins and the large flat areas inside the package leading to the die in the middle create both parasitic capacitance and inductance that is very noticeable at these speeds.Im surprised they even made a DIP package available. For the really fast opamps even SOIC is too crappy of a package, so they instead use QFN or even BGA.

author: TheUnnamedNewbie
author_rank: Super Contributor
timestamp: December 12, 2019, 05:31:55 pm
content: Packaging is a nightmare at higher frequencies. You can't ignore bondwire inductance past a few hundreds of MHz and have to design with them in mind (esp in combination with your ESD-circuits having a good amount of capacitance).Past a few dozen of GHz you get well into the range where packages just don't work. A lot of research is going on there (part of what I do is in this field too).
Different between two type of inverter gate ?  - Page 1
Forum section: electronics / projects

author: Nhan95
author_rank: Contributor
timestamp: November 13, 2016, 07:27:50 am
content: Could you tell me the difference between 2 inverter circuit, which is better and why ?

author: SeanB
author_rank: Super Contributor
timestamp: November 13, 2016, 07:44:26 am
content: Lower one has active pull down and pull up when changing state, and is also capable of driving a larger capacitive load and also can operate at a higher frequency into a specific trace length than the first. Drawbacks are that there is a region in the middle of the logic level ranges where both transistors are turning on and this causes a big supply current spike, so there is a limit on the on resistance of the active devices, plus there is a power dissipation peak there on slow changing inputs.First one at least has a fast falling edge, but the rising edge is slow, from the RC time constant of the output loading and traces. However it does not have a current spike, and with slow edges acts as a somewhat linear amplifier. Current draw when output is low however means a constant power dissipation, and a different current between high and low outputs.The first is not good to clock logic circuits that use latches, as it will have too low a rise time, but will do fine for simple gate logic, while the second is capable of driving with a much reduced rise and fall time.

author: German_EE
author_rank: Super Contributor
timestamp: November 13, 2016, 09:30:27 am
content: The first schematic has an output which is pulled down hard but the pullup is a simple resistor.The second schematic has an output which is pulled up OR pulled down hard, this sort of output can source or sink much more current

author: TheoB
author_rank: Regular Contributor
timestamp: November 13, 2016, 05:48:03 pm
content: The first one was used before complementary mos processes existed. They simply only had NMOS and resistors, no PMOS. It also allowed to tie multiple inverter outputs together to create a wire-orred NOR gate. But the static current when the output is zero really is a waste of energy. You can find this on wikipedia as wellhttps://en.wikipedia.org/wiki/Inverter_(logic_gate)
Different ferrites in series on mains cable - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: February 03, 2025, 11:41:08 am
content: Hi,when using clip-on ferrites on mains cables, in order to cover a wider range of frequencies, can you place two different clip-on ferrites next to each other on the same cable?And to maximise their effect, is there a minimum gap between the two that need to be kept? Or is it better for them to be right next to each other?Thank you

author: jwet
author_rank: Frequent Contributor
timestamp: February 04, 2025, 04:19:05 am
content: You can do this. Spacing isn't critical. Its likely unnecessary, the ferrite guys make a lot of mixes and probably make what you need.

author: Konkedout
author_rank: Frequent Contributor
timestamp: February 04, 2025, 05:17:46 am
content: I think that putting them next to each other ought to be good. One other thing...look into Metglas for broadband noise suppression.Some years ago I wound a test choke using Metglas (nanocrystalline metal) and it provided broader band suppression than I got from ferrite. But if you are just making one or two of something...I suppose you want something "off the shelf" (hopefully not fallen off the shelf and broken) so one or two ferrite sleeve suppressors might be better.

author: ricko_uk
author_rank: Super Contributor
timestamp: February 07, 2025, 02:24:42 pm
content: Thank you both

author: raftronik
author_rank: Contributor
timestamp: February 07, 2025, 02:40:32 pm
content: Hello,this might helpEvaluating Clip-On Ferrite Beads with your nanoVNA

author: PGPG
author_rank: Frequent Contributor
timestamp: February 07, 2025, 03:50:40 pm
content: Quote from: ricko_uk on February 03, 2025, 11:41:08 amI have bought 10 clip-on ferrites about 20 years ago. Made some tests and then they were in my drawer until year ago when I put 7 of them at oscilloscope supply cable (3 I used in different places). I just wanted to cut ground loop at high frequencies.Such ferrite is like resistance at HF (200Ω range). When you put more of them you get the sum of resistances.At the same time we ordered USB oscilloscope and when it came I fount that using it (laptop battery powered) I get about the same results as with standard scope with all these ferrites.

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: February 07, 2025, 04:49:44 pm
content: Wrapping a cable 2 or 3 times through a ferrite is far more effective than a single "clip on". These people have a large 31 mix problem solver ferrite clip on type:https://www.hamgoodies.co.uk/SJ

author: ricko_uk
author_rank: Super Contributor
timestamp: February 08, 2025, 11:00:45 pm
content: Thank you all
Different gnd polygon question - Page 1
Forum section: electronics / projects

author: Karamel
author_rank: Regular Contributor
timestamp: February 06, 2016, 11:21:51 pm
content: Hi,I have a one question about pcb design.Below, there is a pcb which i have found it from aliexpress. You can see clearly that, pcb has a different gnd polygon. Gnd pad was not connected directly. This was connected with wire which located inside gnd polygon.What is meaning of that? Why did it use?

author: ThomasDK
author_rank: Regular Contributor
timestamp: February 06, 2016, 11:26:58 pm
content: My guess would be that it is used as a crude current sensing resistor.What's on the other side?

author: Karamel
author_rank: Regular Contributor
timestamp: February 06, 2016, 11:30:32 pm
content: I guess not.maybe i am mistaken. I dont know.http://tr.aliexpress.com/item/5pcs-lot-DC-DC-step-up-down-power-supply-Converter-voltague-regulator-LM2596-LM2577-DC-35V/1996705981.html

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 07, 2016, 04:00:35 am
content: In cheap Chinese products, there is often no accounting for purpose or reason...Often, slotted conductors will be used to push current flow into component pins, like a filter capacitor or shunt resistor. That wouldn't make much sense here.If it is being used as a shunt, that's even worse, because copper has quite low resistance and high inductance, and a terrible tempco. So the DC voltage drop is small and extremely drifty, and the AC voltage drop is dominant at switching frequencies.Tim

author: Karamel
author_rank: Regular Contributor
timestamp: February 07, 2016, 05:24:55 am
content: Hi tim. Thank you so much for your replying.Could you show and explain any slotted conductor application? I am an electric engineering student who is attending 1st year. Sometimes, i cannot understand cleary.Best regards.

author: Karamel
author_rank: Regular Contributor
timestamp: February 07, 2016, 12:06:50 pm
content: Could you support your knowlage with documents or pictures? Which book do i have to read for learning this stuation?

author: djQUAN
author_rank: Frequent Contributor
timestamp: February 07, 2016, 12:20:56 pm
content: It is commonly seen in chinese DC-DC modules used as current shunts. Yes, it is highly inaccurate and has a high TC but it is essentially free and (sort of) does the job so they do it.I have those CC-CV chinese modules and I traced them out so they are indeed used as shunts.
different mosfet package of same rating - Page 1
Forum section: electronics / projects

author: electros6
author_rank: Regular Contributor
timestamp: November 23, 2014, 05:08:48 am
content: Hi guys,while searching for a mosfet I noticed that STP9NK90Z and STW10NK80Z has same voltage and power dissipation, but the former is in TO-220 package and later is in TO-247. Both have same rating what make them to choose different package what are the factors affect this parameters.

author: David_AVD
author_rank: Super Contributor
timestamp: November 23, 2014, 07:57:18 am
content: Maybe the larger package has a better heat transfer (to heatsink) rating?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: November 23, 2014, 02:17:43 pm
content: Semiconductor ratings are with the device in a bath of boiling freon. When they say "case temperature 25C", they don't mean "hook it up to a block of copper at 25C", they meanall exposed points on the case surface are 25.00C!Since most of the heat goes out the metal plate under the chip, the ratings are very similar between DPAK, D2PAK, TO-220 and TO-247 devices, being limited by plate thickness and die size.Moral of the story: the power dissipation rating hasabsolutely nothing to do with how much you can dissipate in a typical heatsink assembly.There is no substitute for a good thermal design.Tim
Different output from tall vs short xtal - Page 1
Forum section: electronics / projects

author: Circlotron
author_rank: Super Contributor
timestamp: September 04, 2014, 01:42:30 pm
content: I use a 4MHz xtal on a micro for a board I make regularly. I used to use the taller HC49U style and a while back went to the shorter HC49S. Then just the other day I notice a difference in the oscillator signal level between the two. On a 5V supply the tall xtals gives about 2V p/p and the short ones about 1.5V p/p. The taller ones have a disc inside of about 7mm diameter IIRC so the short ones must be really tiny.Is this difference in output to be expected, and are there other things to watch out for like how easy or quickly one or the other starts up?

author: Paul Rose
author_rank: Regular Contributor
timestamp: September 04, 2014, 01:51:19 pm
content: I've heard from ham radio guys building ladder filters that the HC49S tend to have lower Q. You ought to be able to see this parameter in the crystal datasheet.Also see:http://www.foxonline.com/techfaqs.html#a12Quote
Differential Amp. with a notch on output - Page 1
Forum section: electronics / projects

author: Yaroooo
author_rank: Regular Contributor
timestamp: December 07, 2020, 01:31:25 pm
content: Circuit is used to:1) Read an encoder output and level shift it to 3v3 from 24v;2) Convert a 0-10V input signal to 0-3v3;Both of 1 and 2 point should be usable ad same time. Point 2 works correctly while point 1 have a strange output with a "Notch".Here's schematic:In both tests where GND is connected with GNDS and where not, there's no noticeable difference.What oscilloscope is reading:This are test I've tried (adding capacitors):- A capacitor on R6 doesn't provide any difference.- A capacitor between pin 2 and pin 3, create me a sinusoid when signal should be low, even 1pF.- I can remove this "Notch" by adding a capacitor between R58 endings of about 22pF and this solve my encoder problem. But 0-10V conversion doesn't work anymore because a fixed input voltage is converted to sinusoidal output.- I've double checked power supply and ground of my board. I've a decoupling cap nearby amplifier, solid ground plane under it, GNDs via nearby each ground point on schematics. Also a clear +24V square wave, generated by a lab equipment, on amplifier input pin.Another test I've done, is to change MCP634 with an similar one. But nothing changed (just slew rate).Also, touching by finger resistors placed on diff.amp. inputs (i finish my ideas) to test, I've found that this solve the problem on encoder and also, when switching to 0-10V mode, this works perfectly.

author: Marco
author_rank: Super Contributor
timestamp: December 07, 2020, 06:59:14 pm
content: MCP634 is not rail to rail input, it's going half a volt too high.

author: KT88
author_rank: Frequent Contributor
timestamp: December 10, 2020, 12:43:34 pm
content: Besides the issue Marco mentioned you run into CMRR limitations when the edge rate is getting high. This applies even if your input is single-ended - the voltage at the inverting and noninverting inputs counts...CheersAndreas
Differential amplifier - Page 1
Forum section: electronics / projects

author: arh8080
author_rank: Newbie
timestamp: May 16, 2016, 05:26:55 am
content: Hi this circuit how it works?Please help meExcuse FriendsHow Output Can Change Value From 500mv to 1200mv?My English is not so good Excuse me.

author: Marco
author_rank: Super Contributor
timestamp: May 16, 2016, 08:27:27 am
content: Your image upload server is not responding.

author: danadak
author_rank: Super Contributor
timestamp: May 16, 2016, 02:10:19 pm
content: Looks like an integrator to me. R5, C1 set time constant. And DACused to bias up the OpAmp, for what specific reason (using a DAC)I do not know.R2 and R3 also a part of biasing inputs (inverting).Vbias = 3.6 * ( 10K / (10K + 18K ) ) =~ 1.3VMaybe the DAC is used to handle the errors in R2 and R3.Regards, Dana.

author: Marco
author_rank: Super Contributor
timestamp: May 16, 2016, 03:16:56 pm
content: No DC feedback path ... something screwy going on.

author: danadak
author_rank: Super Contributor
timestamp: May 16, 2016, 04:43:30 pm
content: Good point Marco, that circuit will eventually stop functioningdue to accumulated charge on C's.And input range not R-R. ~ 1V off the positive rail.Regards, Dana.
DIfferential amplifier filter question - Page 1
Forum section: electronics / projects

author: teslinius
author_rank: Regular Contributor
timestamp: June 12, 2022, 04:28:59 pm
content: I use a differential amplifier with op07 to amplify voltage drop of a shunt resistor, i set the gain to 17.4. The problem the output of the opamp is very noisy, supply voltages are clean (< 10mV), but the problem is that it's an electronic load, has common gnd and so the noisy voltage from cheap smps that i'm testing gets in the opamp input, so i need to add a filter,or maybe there is a different way to solve this?, i'm gonna try rc, since the opamp inputs use very low current (< 1uA) i can use few k value resistors and 100nF cap, not sure if i should place it on the both inputs or on the output or even both. I found a few schematics on the internet that look ok, but the problem is that max voltage will be 150V, and if i place a cap between input and gnd the difference of potentials will be 150V which will require a physically bigger cap, so i should place it between the inputs like in some schematics

author: Terry Bites
author_rank: Super Contributor
timestamp: June 12, 2022, 05:34:56 pm
content: Unless the components are very well matched, your CMRR will be degraded. If one or both inputs go outside the supply rails you'll have an electroboom experience. I assume you are measuring current from a high side shunt. If so you'll be much better off using a made for purpose HV diff amp like a AD8479 or INA149 with a post filter. Put some back to back diodes across your shunt to limit the spike amplitudes.

author: teslinius
author_rank: Regular Contributor
timestamp: June 12, 2022, 10:07:46 pm
content: Thanks, i didn't know you can get already premade differential opamps, i am using 0.1% 25ppm resistors so they should be pretty well matched, so diodes like this, or no probably they should be placed before the resistors?, and a rc filter on the output?

author: Terry Bites
author_rank: Super Contributor
timestamp: June 15, 2022, 02:28:14 pm
content: The voltage across the shunt is tiny compared to the Vf of a diode. Put them them at the amp inputs. Add the low value resistors and a filter cap to polish off some noise. Experiment with caps but keep R low to avoid upseting the balance of the amp's input.
Differential comparator with dynamic hysteresis - Page 1
Forum section: electronics / projects

author: Hadys
author_rank: Newbie
timestamp: December 15, 2017, 02:40:11 am
content: Greetings,I am having great difficulties in a recent project for my university. I have to create and calculate a scheme of a differential comparator with an OP AMP and a dynamic hysteresis |UthH|=±5V with a minimum possible static threshold of the time-domain of the dynamic hysteresis 3*tau=500µs.I have found this circuit but I am not quite sure if it is correct. Basically AWG1 is the main signal while AWG2 is added noise. Wtih connecting J4 and J5 I add dynamic hysteresis.Is this the full circuit?How do I calculate the elements to fulfill the 3*tau=500µs requirement?How do I fulfill the |UthH|=±5V requirement?What should I look for in the datasheet while choosing an op-amp?I would greatly appreciate any help on this matter.Best regards
Differential impedance in a 4-layer board: Through-hole vias VS Top+Bottom layer - Page 1
Forum section: electronics / projects

author: TnF
author_rank: Contributor
timestamp: February 19, 2021, 02:48:30 pm
content: Hello. I am designing a small hack dongle to play with DisplayPort EDID and other stuff of which i will have to passthrough the main data differential signals.While i could solder a small section of displayport cable for those 4 main pairs i prefer to use a pcb.I expect the length to be about 50mm;My questions is would it be better:a) Have the signals travel inside the shielded layers (layers 2+3) using through-hole vias (since the connectors need to be soldered to top and bottom layer) and deal with the reflections do to the extra stub of the vias? (since JLCPCB doesn't offer burried vias)b) Have the signals travel on top and bottom layer with the middle layers providing the shield?c) Throw a coin, it should/won't work both waysIt needs to not compromise the signal integrity to allow for DP v1.4 HBR3 operation (8.1Gbps per lane).I could also use thinner pcb to reduced the stub distance of the vias, and i could even try manually backdrilling the vias very carefully (my guess this would be a VERY difficult solution)

author: nctnico
author_rank: Super Contributor
timestamp: February 19, 2021, 05:28:51 pm
content: The question is not 'what is better'. The question is: what is produceable. With the 4 layer 1.6mm stackups JLCPCB provides the only choice is to use the outer layers with a thin dielectric layer. Their JLC7628 with a .2 mm dielectric offers a good tradeoff between trace width (0.32mm) and distance (0.5mm) to get near a 100 Ohm differential impedance.For their JLC2313 stackup with a .1mm dielectric you'll need .14mm traces with (ideally) a .5mm distance but you can get away with .3mm distance to get a higher trace density. Keep in mind that thinner traces will have a larger variation in width due to etching so the impdedance might be further off compared to using wider traces.Ideally try to rotate the board design at a 45 degree angle so the weave of the FR4 / prepeg influences every trace equally.Edit: typo

author: TnF
author_rank: Contributor
timestamp: February 21, 2021, 08:51:50 pm
content: Thanks for the reply, i thought that after i posted my question but assuming there are no manufacturing concerns my question still stands.. which would be the better option in practice? Having the signals travel in the inner layers means they are mostly shielded by the outer layers but the traces are closer together meaning they would pick more crosstalk too.Also nice tip regarding the FR4 orientation; i am going to ask JLCPCB to see if you can specify thisedit:Using their calculator shows both options are possible;https://cart.jlcpcb.com/impedanceCalculationYour values are off?!?
Differential impedance reference plane or planes? - Page 1
Forum section: electronics / projects

author: ricko_uk
author_rank: Super Contributor
timestamp: November 26, 2024, 12:31:01 am
content: Hi,when you need to calculate the track/gap widths for a controlled differential impedance, if you have a GND plane above the signal layer and a VDD below the signal layer, do you consider both planes or only ground? i.e. would it be an Edge-Coupled Surface Microstrip or an Edge-Coupled Surface Stripline?If I understand correctly, only GND should be used as reference but due to capacitive coupling of the GND and VDD planes (and the very many decoupling caps around the PCB) then the VDD also has some effect. Is that correct or VDD always has an effect the same as GND and needs to always be treated as a GND plane?I am asking because I am thinking of using this 6 layer PCB stackup fro a new PCB:1) Signal2) GND3) Signal4) Signal5) POWER6) SignalThank you

author: Manul
author_rank: Super Contributor
timestamp: November 26, 2024, 01:34:09 am
content: Well, It's all about signal return. If the power plane in question is the one powering the driver and also a receiver, then there is no difference.Simple example. If we have an IC powered by 3V3, we might as well call it's VDD "ground" and it's GND as "-3V3".In practice we preffer GND to be our return path, because usually it's common for everything which might be on the board and outside the board and thus is a universal return path. What you don't want is return path having to make extra jumps or taking extra paths.

author: ricko_uk
author_rank: Super Contributor
timestamp: November 26, 2024, 04:49:23 pm
content: Thank you Manul
Differential input (whetstone bridge) to single ended output - Page 1
Forum section: electronics / projects

author: Glion
author_rank: Newbie
timestamp: January 30, 2023, 08:34:26 am
content: I have a whetstone bridge that can output both negative and positive values. I want to interface this to a microcontrollers ADC that only takes a single ended input 0-3.3vHow can I convert an input (-1v to +1v) to 0-3.3v output?I've looked at instrumentation amp although i would prefer the use of op amps that don't require a negative rail and i'd need to add a DC offset so 0v = 1.65v at the input to the ADC.

author: Kleinstein
author_rank: Super Contributor
timestamp: January 30, 2023, 08:42:09 am
content: An instrumentation amplifier circuit (seprate OP-amps or a ready made chip) is a good way. For the zero shift, just have the reference point at 1.6 V.With only a gain of about 1.6 the common mode range may be an issue and it may not be worth to use the full 3 OP-amp circuit.Depending in the use, one could also have only a half bridge and have the 2nd half already as part of the amplifier.

author: David Hess
author_rank: Super Contributor
timestamp: January 30, 2023, 09:43:31 pm
content: An instrumentation amplifier is the most common way, and the reference input to the instrumentation amplifier can be lifted to 1.6 volts to offset its output by 1.6 volts and allow negative outputs, but if you do this do not forget that the reference input does not usually have a high input impedance so buffering may be required.Check outLinear Technology application note 43 - Bridge Circuitsfor a discussion of the various options. The last one shown in figure 4 on page 4 is one of the more interesting ones, and uses 2 operational amplifiers instead of an instrumentation amplifier.

author: wasedadoc
author_rank: Super Contributor
timestamp: January 31, 2023, 12:42:53 pm
content: BTW the gentleman's name was Wheatstone.https://en.wikipedia.org/wiki/Charles_Wheatstone
differential input ADC for single ended DC measurements? - Page 1
Forum section: electronics / projects

author: SArepairman
author_rank: Frequent Contributor
timestamp: November 07, 2013, 11:54:34 pm
content: What is the deal with using differential input ADCs for single ended DC measurements?There are many delta sigma ADC which demand differential inputs.. but the data sheets seem to like showing AC signals when making these demands. What is the case with DC signals?Can these techniques be used with all differential ADCs or are there any special cases that we should worry about?http://www.ti.com/lit/an/sbaa133/sbaa133.pdfAre there better methods?

author: calexanian
author_rank: Super Contributor
timestamp: November 08, 2013, 12:10:26 am
content: My take, which is probably wrong is it is all driven by noise rejection. a differential input can be used as a single ended input with proper handling on the unused side. As a matter of fact one thing I forget regularly is that AN ins on many pics default to differential or comparator modes on some types!

author: SArepairman
author_rank: Frequent Contributor
timestamp: November 08, 2013, 04:36:11 pm
content: does anyone have a schematic for a multimeter that uses a ADC chip properly? I mean a ADC ASIC, not a traditional capacitor based one like a bench multimeter.

author: jmaja
author_rank: Frequent Contributor
timestamp: November 08, 2013, 07:43:45 pm
content: I know top end Flukes use LTC2435-1 (e.g. U3 inhttp://www.eevblog.com/images/Fluke28pcbbottom2.jpg), which is a 20 bit version of the 24 bit LTC2415-1, which I have used a lot. It is a differential one and it can be used to measure DC. Actually it can only measure DC, since it has 13-15 Hz sampling rate unless you use an external clock signal for sampling.You can measure single ended with differential, but you need to be careful about maximum range and absolute voltages. E.g for LTC2435/LTC2415 the range is +-2.5V at 5V reference and both inputs must be 0-5 V. Also you need to have no capacitance in the input unless you have very low impedance source. The newer generation ones are a bit more tolerant about input capacitance and you can also choose via SPI if you want to measure ground referenced or differential. E.g LTC2492 is from this newer generation. With these you can get ~1 uV noise, thus ~22 bit resolution at 5V without any averaging. I have built a current monitor with ~1 mA noise, ~1 mA offset and at least 1000 A maximum current using LTC2492 using differential measurement. Actually a single LTC2492 is measuring the voltages and currents of two batteries. Usage is very simple, just a voltage divider for measuring higher voltages and a protection resistor for the current measurement. I also needed a small capacitor at the current measurement input for getting low noise in this case due to noisy environment, but very often that is unnecessary and almost always leads to offset etc. errors with this kind of sigma delta ADC.I haven't used other brand sigma delta converters. thus I don't know much about them.
Differential line receiver input cap selection - Page 1
Forum section: electronics / projects

author: rockbassist90
author_rank: Contributor
timestamp: January 22, 2015, 03:25:09 pm
content: I'm using a differential line receiver for a quadrature encoder input and I was wondering was was the most effective method of selecting capacitors for the input lines, example ENC A and ENC A'.Any tips?Thanks.

author: Yansi
author_rank: Super Contributor
timestamp: January 22, 2015, 03:27:15 pm
content: What encoder?What line receiver?What capacitors?Just what? Add MORE information.
Differential Output Op Amps - Page 1
Forum section: electronics / projects

author: nickm
author_rank: Regular Contributor
timestamp: May 18, 2014, 03:34:51 am
content: I have a couple questions about fully differential output opamps like the opa1632.Is there a spec for gain error? I'm looking for if the input is purely differential, how much common mode will be present on the output? and if the input is pure common mode, how much differential mode will be on the output?I threw together a simulated circuit which I think emulates the function, but the performance is limited by the resistor tolerance. There is an inverting amplifier with a gain of one which inverts the unbalanced signal. Then there are two additional inverting amps which inject a common mode signal onto the differential signals. The problem is tolerances, I think with 0.1% resistors you can get about -60dB of gain error. Is there anything i'm missing? As a black box will this perform like a differential output op amp?Or maybe i'm on the wrong path and the more appropriate thing to ask is are there any standard circuits for converting a single-ended signal to a differential one?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 18, 2014, 06:18:30 am
content: The delay won't be matched on the U1 side (complementary inputs will actually be implemented as complementary circuitry), but yes, that looks about right.Real devices have nice high bandwidth circuitry handling the common mode stuff (same or better than the diff aspect), at least the ones that I've looked at, so the common mode output is guaranteed to be quite good regardless of input.Under say 10MHz, just inverting half the signal is good enough. An amp with GBW a few times higher will have fairly low phase shift. And for signals over 10MHz... heck, you might as well use a balun. If it's wideband, you could potentially diplex both, but you might as well find a fancier chip, they're available into the 100s of MHz.Testing a diff amp for CMRR when you're feeding it with an SE signal is...well...kind of dumb, if you get my drift.Tim

author: David Hess
author_rank: Super Contributor
timestamp: May 18, 2014, 01:16:17 pm
content: It is too bad Texas Instruments produced such a sparse datasheet. I have come to expect that of them and it is one reason I try to avoid their products. Linear Technology provides a lot more detail:http://www.linear.com/product/LTC1992http://www.linear.com/product/LTC6362Quote from: nickm on May 18, 2014, 03:34:51 amThe datasheet gives the common mode rejection ratio of the amplifier itself but feedback resistor mismatch including that caused by source impedance mismatch will limit common mode rejection. The Linear Technology datasheets discuss this.QuoteAny differential pair can be configured to do this and the same applies to any differential amplifier. Just connect one of the inputs to signal common or use it as a balance input which will not be necessary in this case because of the common mode input reference.
Differential pair to wireless communication - Page 1
Forum section: electronics / projects

author: BrettK
author_rank: Newbie
timestamp: June 19, 2014, 03:19:43 pm
content: Hi Folks,This is my first post, I hope it makes sense.I have some pre existing equipment that communicates bi-directionally over a differential pair via half duplex with RS485 devices.My question is, how might I go about converting these devices to communicate wirelessly?I have considered the 433MHz wireless modules because I have several spare, and the range required is not huge, maybe 10m (30') ish almost max.I thought about brreaking into the non inverting (A) output of the 485 device and feeding that to my transmitter. Then using a (input common) non inverting and inverting buffer at the other end between the receiver to provide the inverted and non inverted inputs to the 485 chip. Here I would use two modules at differing frequencies for the differing transmission directions. However I found when I rigged this up without the wireless modules, just trying to use a single wire in place of the wireless the transmission could not be established.Subequently, I have thought about using the inputs to the 485, DI, DE, RE| and ROand using these to drive my wireless modules. DEand RE| are supplied by the same pin of the uC, just operaing in complementary fashion, DIand ROeach being attached to their own uC pins.I propose to connect DIand ROto the relevant pins of my wireless modules and use DEto power the transmitters and RE| to control the power to the receivers, thus I will have bi-directional half duplex communication over the wireless modules. - Is this likely to work? I am not sure how the two devices will know how to toggle the state of their enable pin.Can anyone out there confirm that my ideas might work, or have a better idea as to how I might achieve my goal?Regards,Brett.

author: poorchava
author_rank: Super Contributor
timestamp: June 20, 2014, 06:23:10 am
content: I'd use a dedicated RS485<UART> converter chip. You can then either use some transparent communication mode if your module has such capability or use a direct modulation input to the RF IC.

author: David_AVD
author_rank: Super Contributor
timestamp: June 20, 2014, 06:30:49 am
content: How about apair of these modules off eBay?I recently tested the RS232 version and it works quite well.
Differential probe or isolation probe - Page 1
Forum section: electronics / projects

author: ArthurDent
author_rank: Super Contributor
timestamp: February 06, 2019, 08:35:49 pm
content: Every week it seems there is another thread started about misusing isolation transformers or disconnecting the power line ground from scopes and other test equipment. The correct answer to solve the problem is usually to use a differential probe but the really good probes are generally a little pricey and way more complicated than you need if you just want proper isolation from line voltages at low frequencies. Although some of the high end differential probes go into the gigahertz region, it seems that I would be mainly interested in just power line voltage use. I’ve used the traditional ‘one hand in your pocket’ and the high voltage DMM approach but there have been times when I wished I had something better or could use my scope. Most of what I experiment with is test equipment or tube based amplifiers that are referenced to ground so just a resistive voltage divider (in an oil filled case) for D.C. like the one shown below works fine.Several months ago I parted out a strange high voltage D.C. supply and not wanting to waste any parts, saved a board that had several isolated opamps. Recently I got to thinking that I might be able to use one of these to construct an isolation probe. The opamps on the board are Analog Devices AD210BN that have 2500V rms isolation between input, power supply, and output. The board already had TVS protection diodes (SA8.5) on the input so all I’ll have to do is change the ratio/gain resistors and build it into a box and it should be ready to go. I checked it out with my function generator and the sinewave output looks good and the response is flat to about 20Khz. That frequency response may be a little low to check out the PWM frequency in a SMPS but the price was right and it looks like a useful project, at least for me. The AD210BN wouldn’t be too practical for others to use starting from scratch if you had to buy them because the new price is about $114 !
Differential Probe Over Range Indicator Idea - Page 1
Forum section: electronics / projects

author: FxDev
author_rank: Regular Contributor
timestamp: June 09, 2024, 03:05:53 pm
content: I am working on a DIY 1000V differential probe project.I have completed the first stage of the circuit and its simulation. The project is essentially based on the DP10013 model from Micsig. Using the DP10007 schematic that Dave released and all the photos I could find on the internet, I set up a simulation on Proteus and observed that my circuit appears to be working. Of course, I am sure I will encounter hundreds of problems in real lifeAs you know, these types of devices have an over-range indicator. However, I couldn’t fully understand Micsig’s circuit for this. I will also use a microcontroller in my project, just like Micsig did. I selected the 32-pin Puya (030) as the processor.I always think of using comparators, but generally, all high-speed comparators are single-supply and quite expensive. Micsig, on the other hand, used a simple opamp (OPA2171) in their circuit.Do you have any suggestions on this matter?

author: FxDev
author_rank: Regular Contributor
timestamp: June 09, 2024, 04:10:45 pm
content: I think OPA2171 is using for zero input voltage set offset value.They are using simple 3 resistor divider. Then it goes to ADC or Comparator of the MCU.If it exceeds the limits (you can see blue trace) MCU is blinking the leds.Micsig using EFM8BB51 MCU. So they are using P0.3 pins. This pin have "CMP0.P2" features. Response time is not great, around 171ns minimum. But maybe they are using ADC's for that.Puya has comparators too. If i didnt read it wrong, it is better than EFM8.