Low cost logic analyzer probe for Rigol MSO5000 EasyEDA project - Page 1
Forum section: electronics / testgear

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 05, 2020, 10:47:03 am
content: Hi, friends!I'm create project on EasyEDA with circuit and PCB:https://easyeda.com/f33net/digital-probe-rigol-mso5000This is a low cost logic analyzer probe for oscilloscope Rigol MSO5000 with fixded CMOS/TTL logic for 3.3/5.0V input levels with full bandwidth (up to 600MHz if it realy happens during research). It can also be connected to other models with an adapter or using a different cable.All components are accessible on LCSC.You can order board and all components for about $20 (plus shipping) in a couple of clicks.Of course, you will not get beautiful wires with tags for half of the price of an oscilloscope cost for (fuck them) $400!Thanks to guys from EEVblog for pinout of the connector!Dear friends, good news!The Probe is assembled and checked, works correctly.Checked from the built-in generator at 15MHz (generator limit).

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: June 05, 2020, 01:25:45 pm
content: Sorry to be the bringer of bad news but it looks to me like there are issues with your design.If you look at my pinout (below) for my (proven and tested)MSO5000 Budget Logic Analyzer Probe Set design, you will see that pin 1 is top right as you look into the MSO5000 connector, if your picture of the PCB is top side up i.e. the logic inputs are on the top side of the PCB, then your pin 1 on the 50 pin connector is going to be top left. Even if your PCB is plugged upside down, making your pin 1 bottom right, it's still wrong because your pin 1 is now attached to pin 2 (both happen to be ground) but then your pin 2 of D7+ would be connected to the MSO5000's nProbeDetect pin.It also looks like you have got other pins wrong on the 50 pin connector; your pin D6- has D7- next to it but it should be D7+.I would also have at least one 0.1 bypass Cap for each driver IC.Physically, your 50 pin connector isn't going to fit. There can't be any PCB around it as it fits into a shrouded (surrounded) receptacle so your PCB area under the connector is not going to work and PCB either side of the connector also isn't going to work. This is why I set mine up so that a non-right angle connector puts pins either side of my PCB; my thread includes pictures of this.You seem not to have any input protection at all for your LVDS driver ICs, the data sheet says the absolute max input voltage is 5V so logic that hits 5.2V may cause problems. I would have fed these inputs via 200series resistors.Assuming you fixed the problems with the 50 pin connector, your design will only work at 3.3V and 5V levels.Also, the 50 pin connector has to be a socket, not a plug.Mine is this one.

author: ebclr
author_rank: Super Contributor
timestamp: June 05, 2020, 10:45:51 pm
content: I like the idea to use a one channels IC ( SN65LVD....) , Then I think, what about Put this IC on the other side of the cable just on the tip, and use 4 wire for each channel ( +Vcc GND D+ D- ), On the mainboard will make only a motherboard to connect the cable of the tips boards with some termination if necessary, I believe will have a much better spec because wee will have a differential transmission line.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: June 06, 2020, 10:16:15 am
content: Quote from: ebclr on June 05, 2020, 10:45:51 pmOther than the one-IC-per-channel, that's the approach some guy called Gandalf_Sr (aka moi) took withhis design.First he used a voltage level translator to allow a range of logic input voltages and then, as close as possible to the point of capture, he changed the signals to LVDS. He then fed the LVDS signals up the ribbon cable as a differential transmission line, and then tried (as far as possible) to make the Connector PCB routing correct for differential pair and impedance purposes.The 3.3V version has been tested at 200 MHz, the limit of the MSO5000 input.I know that he still has some spare PCBs if you want a set.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2020, 06:36:26 pm
content: Quote from: Gandalf_Sr on June 05, 2020, 01:25:45 pmHi, Gandalf_Sr!Sir, thank you very much for your participation and help!I planned to use a mirror cable:.A regular cable 1:1 is convenient when the devices are standing on each other, but it is very inconvenient when they are opposite - you need to twist the flat cable, and this is very inconvenient. So i changed the pins mirrored.But you are quite right: i turned over the pins, but i did not turn over the rows. This is a mistake, I will fix it.But different polarities of lines in the same row - this is news to me. Are you sure that the positive and negative inputs are mixed? I could not check it, i found a pinout here in the forum and there is a negative polarity on all lines on one side, and a positive completely on the other. Maybe this was later discussed and fixed, i grabbed the wrong option? Or is Rigol such that its polarity doesn't matter?Bypass capacitors for each IC, it seemed unnecessary to me. These chips consume very little current, their noise into power line is very insignificant. Do you think that one capacitor for 4 chips is not enough?Input protection? Yes, i know that the 5V signal can ringing, but the input of these chips is tolerant to 5V, therefore, it is ready to absorb any ringing. Other excess voltages should not be in the circuit under test. At least in the part where you need to pick up the 5V signal. I generally only work with 3.3V logic. I vote for a direct rail-to-rail connection. But, still, in the new version, I will add 100om resistors - those who do not like them will be able to simply short them.Yes, i designed this device specifically for CMOS/TTL, when you need to take a lot of signals inside the circuit and check, for example, time shifts. For other levels, you can use analog inputs to inspect data on transmission lines. Isn't it?Thank you again for participating, for a detailed explanation.I will be very happy if you give your opinion on this message.And sorry for my English.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2020, 06:54:57 pm
content: Quote from: ebclr on June 05, 2020, 10:45:51 pmHi, ebclr!Yes, these chips are tiny and can be placed directly in the test clip body, connect each 4 wires. It's convenient, i agree. But then each test clip should get its own GND tail and this is inconvenient. It is not possible to take one GND from the board for all because you will get a loop on the GND. I think it will be bad.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: June 06, 2020, 08:49:38 pm
content: The mirror cable solves part of my concern. What I can tell you is that the pinout for the MSO5000 connector that I posted above is tested and correct.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2020, 09:05:09 pm
content: QuoteI lost the message where I found pinout. A lot of messages in the topic. You followed and participated in the discussion. How did you find pinot?

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: June 06, 2020, 10:09:17 pm
content: Quote from: S. Petrukhin on June 06, 2020, 09:05:09 pmI got the pinout from this threadhttps://www.eevblog.com/forum/testgear/rpl1116-active-logic-probe-pod-for-1000z-series-teardown/There was an early version in that thread that had some of the + & - LVDS pins swapped but I promise you mine above is correct.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2020, 11:04:21 pm
content: Quote from: Gandalf_Sr on June 06, 2020, 10:09:17 pmThank you very much, sir!I get pinout from message number 3 at the beginning of the thread. But I looked at the topic more carefully, saw a photo of the original board, where we can see clearly the different polarity of the pins of some channels. Later in the discussion, people talked about the reverse polarity of some channels on the scope screen. And then the correct pinout appeared. You even asked about it. Well, I lost 10 bucks and will throw out the PCB that is already in delivery or solder the cable without a connector, taking into account the permutations.Thank you very much!

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 06, 2020, 11:13:23 pm
content: Chinese comrades are having a blast...However, I lived in the USSR and understand a little how the system works...

author: nctnico
author_rank: Super Contributor
timestamp: June 07, 2020, 12:41:03 am
content: I strongly recommend to design for the regular cable and not use tricks like mirroring. It will get messy at some point. You can mount the connectors on different sides of the flat cable without changing the order of the pins to achieve the same.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 07, 2020, 07:48:57 am
content: Quote from: nctnico on June 07, 2020, 12:41:03 amOK, I'll change the angle connector to the regular and make the design for the regular cable.Using a angle connector with a regular cable is very inconvenient.Give me a few hours for a new design.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 07, 2020, 07:16:40 pm
content: OK, friends!The new design is complete.It is in the same project as version 2.0.Thank you all for your help and participation.

author: nctnico
author_rank: Super Contributor
timestamp: June 08, 2020, 12:30:02 am
content: I took a look at your schematics. Why are there 100 Ohm resistors between the LVDS signals at the driver side? These shouldn't be there. LVDS is terminated at the receiver. LVDS is a current sourcing/sinking signaling system and adding extra load is reducing the swing at the receiver.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 08, 2020, 07:01:27 am
content: Quote from: nctnico on June 08, 2020, 12:30:02 amI'm not sure exactly about LVDS, but the terminating resistor is placed on both sides of a symmetrical line, isn't it?Correct me if I'm wrong.In any case, you can not install these resistors at will.

author: ebclr
author_rank: Super Contributor
timestamp: June 08, 2020, 10:14:38 am
content: Your English is just fine, Don't worry about

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: June 08, 2020, 02:40:50 pm
content: Quote from: nctnico on June 08, 2020, 12:30:02 amI asked about thishere. The answer was that the guts of the MSO5000 don't appear to have any terminating resistors - I think the internal IC inputs are RSPECL. So you have to terminate the LVDS signals (which are current signals) on a 100 or 120 Ohm resistor to convert them to voltages. Keep reading from my link and you'll see a load of discussion on that page.In some respects I was designing a circuit with an output into an unknown input although there are some good breakdown photos. Anyway, I have these LVDS terminating resistors on my design and it works with them and it doesn't work without them.Long story short, I think Sergey is right to include the terminating resistors.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 08, 2020, 03:12:27 pm
content: Quote from: Gandalf_Sr on June 08, 2020, 02:40:50 pmYes, I also looked at the photo - there the connector pins are connected to an array of resistors on the visible layer. There may be tracks on the inner layer for terminating resistors, but you can't see the tracks and resistors. And I looked at how it is done on your disign.But why do you say it's a current line? Maybe I not understand the terminology in English, but this is not a line like 4..20 mA, where the signal is transmitted by current. Aren't these resistors the matching ones for the wave resistance?

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: June 08, 2020, 03:25:44 pm
content: Quote from: S. Petrukhin on June 08, 2020, 03:12:27 pmIf you look at the first picture atthis link on LVDS, you will see that LVDS, at its heart, is a 3.5 mA constant current supply that is switched via an 'H' bridge circuit so it actually, it IS a current system which is why you need the terminating resistor to get you the the Hi and Lo voltage levels that the RSPECL inputs expect.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 08, 2020, 04:06:47 pm
content: Quote from: Gandalf_Sr on June 08, 2020, 03:25:44 pmUnderstood. Thanks!

author: tv84
author_rank: Super Contributor
timestamp: June 08, 2020, 04:16:04 pm
content: Quote from: Gandalf_Sr on June 08, 2020, 02:40:50 pmNothing beats the experimental method.

author: sbehnke
author_rank: Contributor
timestamp: July 04, 2020, 06:20:46 pm
content: Looking forward to your testing to see if this works as designed. I'd love to order one for myself.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: July 04, 2020, 07:27:52 pm
content: Quote from: sbehnke on July 04, 2020, 06:20:46 pmUnfortunately, delivery is very slow now, I'm still waiting for LVDS drivers. Subscribe to this topic - I will definitely inform here.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 27, 2020, 12:46:35 pm
content: Dear friends, good news!The Probe is assembled and checked, works correctly.Checked from the built-in generator at 15MHz (generator limit).D0-D7 inputs are connectet to first built-in generator at 5MHz.D8-D15 inputs are connected to second buid-in generator at 15MHz (generator limit).CH4 input is connected as D8-D15 inputs.Both generators have settings: Square, MinLevel=0V, MaxLevel=2.5V (generator limit).Trigger from CH4.

author: tv84
author_rank: Super Contributor
timestamp: August 27, 2020, 01:09:41 pm
content: Show us some pics.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 27, 2020, 01:54:32 pm
content: I recommend replacing R17.I used 100 Om, but the led was very bright, replace to 5.1 kOm.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: August 31, 2020, 11:12:38 am
content: Looks good. The 5.1k LED resistor should allow for 3 or 4 mA of LED current which is good. Looking at the datasheet for the SN65LVDS1, it says that the Absolute Max Vin is Vcc+2 volts so, with Vcc at 3.3V, you should be OK for 3.3 or 5V logic signals.I see you have tantalum capacitors on the LDO regulator - I'm not a fan of Tantalums because a) they are expensive and b) they can fail explosively! Make sure you pick a voltage rating that is at least twice what you will be operating them at. If you can replace them with MLCC capacitors, I would make that change - more reliable and cheaper. There are some aluminum polymer capacitors that can replace tantalums but they are only available for low voltages.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 31, 2020, 02:38:17 pm
content: Quote from: Gandalf_Sr on August 31, 2020, 11:12:38 amYes, SN65LVDS1 have tolerant input for 5V. In addition, the logic of 5V TTL never have a logic level" 1 " equal to Vcc, it is always a little less, because this logic is based on bipolar transistors that have a voltage drop at the junction. The ringing of the signal on the fronts is successfully suppressed and dissipated on the input resistors.I use a lot of tantalum capacitors, ever had a problem. Soviet space and military equipment was saturated with these capacitors. In my opinion, they are good. Here I used only 2 very inexpensive capacitors. I think you needn't be afraid of them. However, the project is open, you can clone it and change the board to any capacitors you like. You can make changes as you wish without restrictions.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 31, 2020, 02:43:25 pm
content: Friends, I found that the output voltage of 4.5V to power the circuit supplied from the oscilloscope was weak and dropped to 4V at load. It seems that the LVDS driver consumes a little, but there are 16 of them and the total current consumption was about 86mA. It turned out that the drivers due to the voltage drop on the LDO does not receive 3.3V, only 3.0V. But the scheme works steadily. 3V is the permissible supply voltage of the LVDS driver.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: August 31, 2020, 03:20:00 pm
content: The voltage regulator you used, the LM1117 has a dropout voltage (Vin - Vout) of about 1100 mV at 100 mA supply which would explain your not being able to get to 3.3V out.I used aMC33375ST-3.3T3Gwhich has a WAY lower dropout voltage, around 115 mV at 100 mA and never more than 500 mV, worst case at full load.I chose my LDOs because they needed to have very low dropout voltages - sorry I missed that aspect when looking over your design.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 31, 2020, 08:31:17 pm
content: Quote from: Gandalf_Sr on August 31, 2020, 03:20:00 pmThank you, sir!I changed the design to use MC33375ST-3.3T3G in the new version 2.1 now.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 01, 2020, 12:27:34 am
content: You're welcome.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: September 01, 2020, 11:34:25 am
content: Quote from: Gandalf_Sr on September 01, 2020, 12:27:34 amI started making an amplifier for built-in generators. The amplitude of 2.5V is very small, I think to make the gain by 2 or 10.I sometimes need to emulate the sensor signal in industrial 24V equipment.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 01, 2020, 01:23:33 pm
content: Quote from: S. Petrukhin on September 01, 2020, 11:34:25 amIt's already been done for the MSO5000, on the threads here somewhere. Here it ishttps://www.eevblog.com/forum/projects/function-generator-booster-for-mso5000/msg2958594/#msg2958594

author: S. Petrukhin
author_rank: Super Contributor
timestamp: September 01, 2020, 01:29:58 pm
content: Quote from: Gandalf_Sr on September 01, 2020, 01:23:33 pmUnfortunately, I didn't see it. My idea is to make a board/adapter that simultaneously fits into both the sockets of the built-in generator and the USB connector nearby. You can take power from USB for this device.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 02, 2020, 09:23:54 am
content: I too thought about designing a PCB that plugged into the USB & the 2 BNC connectors but, if you want to use the USB port for more than 1 thing e.g. mouse, USB drive, power for your voltage doubler, your approach will be problematic. I use SMA connectors so I think a better idea is to build a single PCB that has 2 SMA inputs and outputs, plus a 5-12V power input. Then you can use SMA-SMA cables with a SMA-BNC adapter at the scope end and choose where the power comes from, either from the USB (directly or via a small hub, which is what I use), or from a bench power supply.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: September 02, 2020, 11:30:27 am
content: Quote from: Gandalf_Sr on September 02, 2020, 09:23:54 amIt is not a problem to make an end-to-end USB channel from the oscilloscope's USB connector to the USB connector on the amplifier's PCB.Along the way we can take away a bit of power for the amplifier. I don't like free-standing boxes.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 02, 2020, 12:55:05 pm
content: Quote from: S. Petrukhin on September 02, 2020, 11:30:27 amYes, that is a good idea. One question is to make sure that the 5V supply from the USB connection doesn't bring noise into the amplifiers.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: September 02, 2020, 01:31:19 pm
content: Quote from: Gandalf_Sr on September 02, 2020, 12:55:05 pmWill need to take care of filtering the power supply for the amplifier.

author: Sharp
author_rank: Contributor
timestamp: September 12, 2020, 04:22:36 pm
content: Very good work Petrukhin and the ones supporting youWhat is the next step concerning production ? Do you have a cheap Chinese company looking into doing the production ?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: September 12, 2020, 04:27:10 pm
content: Quote from: Sharp on September 12, 2020, 04:22:36 pmHave not production. This is made for personal use.

author: Michael960
author_rank: Newbie
timestamp: September 28, 2020, 05:00:54 am
content: Hi!First, thank you very much for this idea!I need 13.5 V inputs for car diagnostics. So I'm thinking of extend the circuit to arbitrary higher voltages by putting 5V zener diodes in parallel to the inputs and putting 1MOhm resistors in series to this combination of inputs and zener diodes?Do you see any disadvantages of this?Best regardsMichael

author: S. Petrukhin
author_rank: Super Contributor
timestamp: September 28, 2020, 05:23:27 pm
content: Quote from: Michael960 on September 28, 2020, 05:00:54 amHi, Michael!I think 1mOm is a lot. This is not a good idea at all. The logical zero voltage in the 13.5V line may be the logical high voltage in the 3.3V line.And keep in mind that the voltage of the vehicle's on-board network can reach 14.6V.it is better to use a voltage divider on two resistors.And even better use a more advanced and inexpensive also probe from sir Gandalf_Srhttps://www.eevblog.com/forum/testgear/ms05000-budget-logic-analyzer-probe-set-design/This probe can use external threshold voltage.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: September 29, 2020, 07:18:36 pm
content: Thanks for the plugSir Gandalf_Sr! I've been knighted and I never knew!

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 17, 2020, 03:01:07 pm
content: Friends, did someone use a board of my design? Please write a review if you don't mind.

author: hydrabus
author_rank: Contributor
timestamp: October 21, 2020, 11:42:19 am
content: Thanks for your workI have converted it from EasyEDA to KiCad 5.1.7-1 and done a cleanup and rerouting with match length for the signal D0 to 15 (I have done the schematic from scratch too)The good news is now all is available on KiCad for a version which should work up to 1GSPS (the limit of the MSO5000 LA/TI SN65LVDS1DBVRG4+cables/probes ...).I have changed some parts also to better parts.The big plus is I provide also the JLCPCB SMT script to convert the KiCad BOM/POS to JLCPCB SMT BOM & CPL (see JLCPCB_PCBA directory)

author: TurboTom
author_rank: Super Contributor
timestamp: October 21, 2020, 12:22:10 pm
content: Sorry for my ignorance, but I think it would be sufficient to keep the length of the sum of the individual input and output trace of each comparator equal, which would reduce the amount of wiggles and thus possible EMI and "pulse smearing" considerably.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 21, 2020, 05:03:02 pm
content: Quote from: hydrabus on October 21, 2020, 11:42:19 amYou almost completely redesigne the trace, it was a lot of work to put so many wigglings.I also equalized the length of the output LVDS lines in the first version, but after I saw the photo of the scope board, I realized that this would not give privileges. The Chinese comrades did not even install a load resistor on the LVDS receiver side, let alone equalization differential lines.I'm not much of a high-frequency expert, but it seem like so much wiggling gives parasitic capacitance and inductance. I checked my version at 50 MHz later. The rectangular signal did not give jitter, the image is frozen. But the triangular signal showed a small jitter, probably a slight deviation in the switching level of the LVDS shapers inputs.It will be good if you create a project with your version on EasyEDA - it will be convenient for other people to make your version for themselves, which is important for high frequencies.

author: hydrabus
author_rank: Contributor
timestamp: October 21, 2020, 08:19:14 pm
content: I do not plan to do the work on EasyEDA as I do not know how it work and because everyone shall switch to a real EDA like KiCad as EasyEDA is clearly not good for advanced PCB and match length / high speed circuits...For information the match length is here to avoid Clock skew with design v2.1 seehttps://en.wikipedia.org/wiki/Clock_skewfor more detailsThe rule of thumb for High Speed differential signal (for 480MHz) is each member of a High-Speed differential pair should be no more than 1.25 mm (50 mil) longer than the other member.If you check original design there was huge gap on match length see my document Signal_Length.ods:1) Tuning Match Len Diff Signal DX+/- => Minimal trace was 11.18mm and max was 27.38mm so a delta of more than 16.2mm so it clearly violate the rule (>12 times) to do not exceed 1.25mm delta.2) Tuning Match Len Signal DIX => Minimal trace was 14.16mm and Maximum trace was 75.98mm so a delta of more than 60mmSee referencehttps://blog.zuken.com/how-to-calculate-trace-length-from-time-delay-value-for-high-speed-signals/If you do the computation for a 400MHz it is just 3 times less than the example 1.2GHz so the signal you obtain a clock period of 2500ps with for striplines, the maximum skew should be less than +/-367.5 mil = 9.3345mm and here we have 60mm (>6 times more) ...If you do the computation for a 200MHz it is just 6 times less than the example 1.2GHz so the signal you obtain a clock period of 5000ps with for striplines, the maximum skew should be less than +/-735 mil = 18.669mm and here we have 60mm (>3 times more) ...If you do the computation for a 100MHz it is just 12 times less than the example 1.2GHz so the signal you obtain a clock period of 10000ps with for striplines, the maximum skew should be less than +/-1470 mil = 37.338mm and here we have 60mm (>1.6 times more) ...If you do the computation for a 50MHz it is just 24 times less than the example 1.2GHz so the signal you obtain a clock period of 20000ps with for striplines, the maximum skew should be less than +/-2940 mil = 74.676mm and here we have 60mm so it is ok but not with a big margin ...An improvement to have less EMI/EMC and better differential routing... will be to use 4 Layers (1_Top, 2_GND, 3_PWR, 4_Bot).About the questions:QuoteIt is mandatory to do match length on single ended and differential traces separately.About possible EMI and "pulse smearing" see the paper "Differential Lines Paired with Serpentine as PotentialEMI Aggressors in Mobile Electronic Devices"https://sci-hub.se/https://ieeexplore.ieee.org/document/8114328We clearly see in this paper EMI/EMC are a potential problem on multi GHz (but not for signal < 500MHz) which is not the case here as we cannot exceed 500MHz anyway with 1GSPS and in fact when you have added all limitations of hardware it will be probably limited to max 200 or 250MHz but the improvements with match length / serpentine + multi via to GND (to reduce EMI/EMC ...) remove the limitation of the original PCB which is limited to less than 100MHz signal and shall allow to capture up to 250MHz(or even up to 500MHz in theory) signal without clock skew issues.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 22, 2020, 09:24:12 pm
content: Quote from: hydrabus on October 21, 2020, 08:19:14 pmI have some knowledge in the alignment of the length of the lines. But all efforts are still leveled by the scope itself, where the length of the lines was not thought of. In addition, the bandwidth of the logic analyzer is limited and it does not reach the value you mentioned. I made a simple, very cheap option. This is by no means an accurate or calibration device. Most people don't need to take measurements at high frequencies. I don't have more than 50 MHz anywhere.You've done some serious research. Your option is worthy of special attention for special cases for cool professionals, but they have a lot of money to buy an expensive scope and logic analyzer.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: October 23, 2020, 12:43:23 am
content: I'm pretty sure that the LA probe on the MSO5000 series samples at 1 GHz so the absolute maximum frequency that could be sampled is reasonably about 400 MHz. At 400 MHz, the wavelength in copper is around 700 mm. Worrying about less than 2 mm trace length matching is pointless IMHO.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 23, 2020, 12:56:23 am
content: Quote from: Gandalf_Sr on October 23, 2020, 12:43:23 amThe Rigol MSO5074 specification states that the maximum LA frequency is 200 MHz.

author: Sharp
author_rank: Contributor
timestamp: November 10, 2020, 03:45:08 pm
content: @hydrabus and @PetrukhinThank you for your excellent work - very appreciatedAre we now looking into two deterrent designs and two deferent tests ? or are you working together on this project ?

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: November 12, 2020, 12:20:47 pm
content: Quote from: S. Petrukhin on October 23, 2020, 12:56:23 amYes, they are saying that they don't spec forlogic clock frequencieshigher than 200 MHz but you need at least double this as the sampling rate; again, I am pretty sure that the MSO5000samplesthe LA pins at 1 GHz, that's why there's a 1 nS jitter when you're looking at 200 MHz waveforms.

author: Gandalf_Sr
author_rank: Super Contributor
timestamp: November 12, 2020, 12:28:24 pm
content: Quote from: Sharp on November 10, 2020, 03:45:08 pmThe 2 projects are both LA probe leads that plug into the Rigol MSO5000 series scopes but they are completely different designs.Mine came first. I have looked at S.Petrukhin's design and offered him my advice and what I believe is constructive criticism. I am not running a business (at least not one selling LA probe PCBs) and I don't feel like I'm in competition here. I now realize that you were asking about Hydrabus' design vs S.Petrukhin's. I have a completelyunrelated design here.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 15, 2020, 11:40:07 am
content: Quote from: Sharp on November 10, 2020, 03:45:08 pmI quickly made a simple version myself which is easy to repeat by ordering PCB and accessories in a couple of clicks.. I was really helped by the guys in this forum, who studied and gave information about the standard device. @Gandalf_Sr especially helped-he found errors and suggested them to me. @hydrabus upgraded the board and made an independent version.

author: simogi
author_rank: Newbie
timestamp: November 26, 2020, 10:33:31 pm
content: Good evening,I just bought a rigol mso5000.I came across this blog.I went to the Chinese site:https://easyeda.com/f33net/digital-probe-rigol-mso5000I saw an opportunity to purchase components.But I don't see an opportunity to buy the board.I know it's a simple question but can you help me?Simogi

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 26, 2020, 11:59:07 pm
content: Quote from: simogi on November 26, 2020, 10:33:31 pmHi!I answered you on that site: you need to open the PCB in the Editor (see this name button) and select [Fabrication / PCB Fabrication file (PCB)] from the menu there. Then choose when ordering 5 pieces - they will cost $2 plus shipping.

author: simogi
author_rank: Newbie
timestamp: November 27, 2020, 06:01:25 pm
content: Thanks so much for the reply.Now I have succeeded.I saw in the BOM (components list) that the connectors and flat cable between rigol and board are missing. Do you know them or do you know where I can get a pre-made cable?Thanks againSimone G. O.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 27, 2020, 06:30:20 pm
content: Quote from: simogi on November 27, 2020, 06:01:25 pmUse it for your fun.I had connectors for the wire and the wire itself, I bought them in advance. These are simple items that you can buy at a local store. I didn't search for them on LCSC. Here are the links to Aliexpress that I used to buy:Pogo pin P100-F1:https://aliexpress.com/item/4001365760976.htmlDupon socet for pins:https://aliexpress.com/item/32717763865.htmlSingle cable 28 AWG 5 meters for pins:https://aliexpress.com/item/4000009001537.htmlTest clips:https://aliexpress.com/item/4000550690107.htmlTest clips:https://aliexpress.com/item/4000340698351.htmlFlat cable 50 wire:https://aliexpress.com/item/32946950330.htmlSocet for flat cabble 50 pin:https://aliexpress.com/item/4000114961257.html

author: simogi
author_rank: Newbie
timestamp: November 27, 2020, 08:13:29 pm
content: I took it all,Now I have everything to start.ThanksSimone G. O.

author: calippo
author_rank: Newbie
timestamp: November 28, 2020, 10:43:42 pm
content: Any feedbacks?As Kicad user, I was planning to pursue the JLCPCB option too.Quote

author: nullik
author_rank: Contributor
timestamp: December 28, 2020, 12:12:38 am
content: Quote from: calippo on November 28, 2020, 10:43:42 pmI checked design in KiCad and think all fine. Also I got my PCBs with this design.Now I waiting electronic componets for checking device.After I get the EC and check device, I will write the results here.The design is not perfect and can still optimize pcb.I will check the delay in differential pairs, if i found mistakes then I make my own PCB.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 28, 2020, 12:46:48 am
content: Quote from: nullik on December 28, 2020, 12:12:38 amIt looks like you used the hydrabus design. As discussed here, and according to the results of my tests, its changes will not interfere with the work, but for the bandwidth of LA MSO5074 they are not it does not matter.

author: nullik
author_rank: Contributor
timestamp: December 28, 2020, 02:53:14 am
content: Quote from: S. Petrukhin on December 28, 2020, 12:46:48 amYes, I use his design. Perhaps you are right. But I know strict requirements high freq designs like USB bus.Differential pairs work only if they have the same delay. And they become very easily ineffective if this rule is violated.A simple example of a USB bus, with bad cable it can work ustable, losesynchronization, data transfer speed drops.The correct way is not to align the length of the lines, the correct is to align their delays.Also for a better high freq design and low noise, you need to have at least a 4-layer PCB.At high frequencies, we are very dependent on reactive capacitances and inductances.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: December 28, 2020, 03:29:42 am
content: Quote from: nullik on December 28, 2020, 02:53:14 amThis has already been discussed. Rigol engineers did not even bother to install load resistors on the receiver side and did not turn them on inside the FPGA, and you will worry about leveling a couple of centimeters of the track. It's like covering up the gold of the thatched roofs.You create more inductance and capacitance by looping the track.

author: nullik
author_rank: Contributor
timestamp: January 13, 2021, 06:02:01 am
content: I checked KiCad logic probe. All works fine.I gave my pcb to people. I will be making the next version of the probe with a different plug on the output so that I can use high frequency shielded wires from dslogic.https://www.dreamsourcelab.com/shop/accessories/shielded-fly-wires/

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 13, 2021, 07:12:01 am
content: Quote from: nullik on January 13, 2021, 06:02:01 amShielded doesn't mean high-frequency.High-frequency lines must be matched.And for shielded wires, you can use double female pin, because each input has its own personal Gnd pin in an existing connector.Get a savings of 23 bucks.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 13, 2021, 07:16:03 am
content: By the way, the LVDS chip is very small. For complex environments where there are requirements for protection against interference, it is possible to embed this chip directly into the tip of the probe and transmit a stable LVDS signal directly from the spot.

author: yelworc
author_rank: Newbie
timestamp: March 01, 2021, 11:25:11 am
content: I was on the hunt for nice probes to go with this,Dream source seems to be a good bet.https://www.dreamsourcelab.com/shop/accessories/shielded-fly-wires/I'll let you know about the compatibilityThere's also these if you want dirt cheaphttps://www.aliexpress.com/item/33060152163.html?spm=a2g0o.productlist.0.0.350bd45aRmKXPk&algo_pvid=6ace0999-564b-4c96-a24d-4ea97aea9a24&algo_expid=6ace0999-564b-4c96-a24d-4ea97aea9a24-26&btsid=0bb0624116145943214698372e4b06&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

author: S. Petrukhin
author_rank: Super Contributor
timestamp: March 01, 2021, 11:38:10 am
content: Quote from: yelworc on March 01, 2021, 11:25:11 amHere published a list of the materials I used:https://www.eevblog.com/forum/testgear/low-cost-logic-analyzer-probe-for-rigol-mso5000-easyeda-project/msg3344750/#msg3344750I made myself tails for the probes from thin silicone wires very soft. The probes you found on Aliexpress use an ordinary PVC wire that is very hard.

author: justanothername
author_rank: Regular Contributor
timestamp: March 09, 2021, 05:57:04 pm
content: I ordered the PCBS of this they came today. Thank you for this.Two remarks:Firstly the groundplane is only on bottom and hatched. There is no technical reason to make it hatched. Better use a solid plane on both sides.Secondly, and this is way more relevant, the plane is not connected to the probe ground. It is floating. That is not a good idea in my opinion. Better connect it to GND or do not use a plane at all.This weekend is assembly time and testing.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: March 10, 2021, 07:12:18 am
content: This is a two-layer board, there is no free layer for solid fill.Using a grid in a polygon is just as good for shielding and removing static electricity as a solid fill, but the grid has many times less capacity to the tracks.However, it is not a shielding layer and it is not connected directly to the Gnd, but neen connext to PE, because its task is to remove static charges, it is connected via the resistor R18 and the capacitor C5.I chose bad nominals just to avoid creating new positions in BOOM, But this is not essential. It is best to use a 1MOm resistor and a 100pF high-voltage capacitor there.If you wish, you can close R18 and get a grid rigidly attached to Gnd.

author: bbandi
author_rank: Newbie
timestamp: March 20, 2021, 08:19:29 am
content: Hi,This design should work with the 1074z, right? I mean, with a custom 68pin-50pin converter of course.Thanks,Andras

author: S. Petrukhin
author_rank: Super Contributor
timestamp: March 20, 2021, 01:31:48 pm
content: Yes.

author: justanothername
author_rank: Regular Contributor
timestamp: March 22, 2021, 07:37:53 pm
content: Ok, I built this and it seems to work. The negative edges are omewhat jittery at 5 MHz (with the DG1022 as source). Can't tell why. I tried connecting the plane to gnd with solder jumper and I installed more decoupling capacitors.Does not have any effect. Could be a display thing, or something with my generator or it could be caused by ringing (my guess). Since I do not have the original probe, I can't say if it behaves differently, better or worse...Anyway for normal usage it is satisfactory so I wont dig any more into this. Thanks again for the design.

author: ebclr
author_rank: Super Contributor
timestamp: March 26, 2021, 12:47:51 am
content: On the Output of MC33375ST-3.3t3g on schematics show 4v, The correct value isn't 3.3V? Or do you use another regulator?

author: normi
author_rank: Regular Contributor
timestamp: May 04, 2021, 06:38:56 pm
content: Quote from: ebclr on March 26, 2021, 12:47:51 am4V is the voltage supplied by the scope, and is regulated down to 3.3V.

author: normi
author_rank: Regular Contributor
timestamp: May 04, 2021, 06:50:14 pm
content: Got this built and was able to use it up 160MHz, there was jitter, but I have not worked out whether this could be improved with probing technique. Also I only had a few Dupont cables pieced together to use as probes. I used an FPGA which generated a 160MHZ clock then broke this into 4 bits which would count to 16, (0-F). The parallel decoder was used for this.See attached screen shot.

author: normi
author_rank: Regular Contributor
timestamp: May 04, 2021, 06:54:30 pm
content: Thanks to all who contributed to the design.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 05, 2021, 11:49:52 am
content: Quote from: gurong60 on March 22, 2021, 01:49:26 pmIt makes no sense to make 4 layers, fill two of them with a power bus and create parasitic capacities.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 05, 2021, 12:02:45 pm
content: I didn't use any stabilization tools for jitter. LVDS chips have a good slope of the output edge, and are quite good at determining the level at the input. But the probe lines introduce their own distortions. At a frequency of 160 MHz, this is already noticeable.However, the observation by the logic probe of periodic signals in continuous mode (then where the jitter is observed) not really necessary. You can use analog channels for such purposes. I think digital inputs are more reasonable to use in packet capture mode with a sweep trigger in normal mode or a single shot.

author: moelski
author_rank: Newbie
timestamp: August 09, 2021, 08:47:56 am
content: Hi !Any chance to use this probe with my Rigol MSO1104Z ?Dominik

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 09, 2021, 12:34:48 pm
content: Quote from: moelski on August 09, 2021, 08:47:56 amYes, but need made inteface cabble for MSO1104Z plug.

author: Peter_the_diver
author_rank: Newbie
timestamp: September 26, 2021, 01:54:13 pm
content: Hallo guys and thank you for that graet stuff here! I have ordered a PCB for a logic probe as described here. Unfortunately the fucking SN65LVDS1DBVRG4 is currently not availlable. The market is swept empty - worldwide, one year delivery time! Thus I have decided to make a new board on the basis of Sergeis circuit, with the same PCB format. I have called it version 3.0. However I have used theSN65LVDS391D. This seems to be the the same LVDS driver but in a 4 channel housing. With the SIOC16 housing the routing can be structured verry well. All LVDS-lines have almost the same length now. And the best - these parts are availlable for a fair price (Mouser. DigiKey, Farnell...). Please find attached the design documents here. By the way - it is not yet tested! Feel free to use it - but on your own risk.regards Peter

author: S. Petrukhin
author_rank: Super Contributor
timestamp: September 26, 2021, 02:46:26 pm
content: A good solution, Peter!But it seems to me that we should not worry about the length of LVDS lines in real life.I was checking my version, where the lines have a big difference in length, on the 36 MHz SPI bus.Didn't detect any interference or jitter.

author: Peter_the_diver
author_rank: Newbie
timestamp: September 26, 2021, 03:11:00 pm
content: you are right Sergei - last but not least you have to consider thetotallengt of the lines (driver output - ribbon cable - LVDS-input). So small differences on the little bord are negligible. However, the use of the SOIC made it pretty easy to realise this evenly routing.Peter

author: S. Petrukhin
author_rank: Super Contributor
timestamp: September 26, 2021, 03:51:53 pm
content: Yes, if we look at the photos of the oscilloscope board (good people published them in this forum), the Chinese guys do not bother with this question at all.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 18, 2021, 08:03:45 am
content: It showed up on ebay.https://www.ebay.com/itm/224648789536

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 18, 2021, 08:37:34 am
content: Quote from: MegaVolt on October 18, 2021, 08:03:45 amIt's funny to see a modification of my device in the commercial sector on ebay.

author: MegaVolt
author_rank: Frequent Contributor
timestamp: October 18, 2021, 08:40:09 am
content: Quote from: S. Petrukhin on October 18, 2021, 08:37:34 amYes. And the seller is not from China.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 18, 2021, 08:54:02 am
content: Quote from: MegaVolt on October 18, 2021, 08:40:09 amIt is ok. I have not expressed any restrictions for use, including commercial.The seller has a good rating, good reviews - probably a good person.In addition, only 5 pcs. - probably, this is the sale of extra copies.If you wish to produce these probes for sale, you can safely do it without any restrictions.

author: Landvogt
author_rank: Newbie
timestamp: January 21, 2022, 08:40:10 pm
content: Hi folks, I'm new here. It's incredible how you guys work together constructively. I was really enjoying reading through this thread. Unfortunately, the SN65LVDS1DBVRG4 is still not available. Has anyone tried Peter's workaround yet? Did it function correctly?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 21, 2022, 09:31:56 pm
content: Quote from: Landvogt on January 21, 2022, 08:40:10 pmLVDS drivers are quite a lot from different manufacturers, both -1-channel and multi-channel. You can get them even from a broken monitor. They are all standard, differ only in bandwidth mainly. Very often they are even completely interchangeable, including by the location of the pins.I haven't checked thoroughly, do it yourself, but I think that this CHIP can completely replace it - just install it. It is available on LCSC:https://lcsc.com/product-detail/span-style-background-color-ff0-LVDS-span-ICs_Texas-Instruments-DS90LV011AQMFE-NOPB_C130172.htmlBut this CHIP is intolerant for 5V TTL input, 3.3V only.I chose the most inexpensive and affordable at that time on LC SC in large quantities. Nevertheless, they work perfectly at a frequency of 36 MHz - I worked at this frequency with the SPI bus and everything was fine.Unfortunately, the crooks have severely disrupted the semiconductor market.

author: giorgiofox
author_rank: Newbie
timestamp: February 20, 2022, 07:51:33 pm
content: Hello,now it seem very difficult to get all the components (at last, in Europe)can anyone can help me with supplier or components?Thanks in advanceGiorgio

author: S. Petrukhin
author_rank: Super Contributor
timestamp: February 20, 2022, 07:58:05 pm
content: Quote from: giorgiofox on February 20, 2022, 07:51:33 pmhttps://lcsc.com/product-detail/span-style-background-color-ff0-LVDS-span-ICs_Texas-Instruments-DS90LV011AQMFE-NOPB_C130172.html

author: crgarcia
author_rank: Regular Contributor
timestamp: March 06, 2022, 06:14:28 pm
content: Quote from: S. Petrukhin on February 20, 2022, 07:58:05 pm0 In Stock

author: S. Petrukhin
author_rank: Super Contributor
timestamp: March 07, 2022, 07:34:29 pm
content: Quote from: crgarcia on March 06, 2022, 06:14:28 pmUnfortunately, the CHIP crisis problem has not been solved. I think it will be even worse, the world is changing a lot.

author: crgarcia
author_rank: Regular Contributor
timestamp: March 10, 2022, 09:11:59 pm
content: yes, I guess I have no option but to buy the 400usd original component. Anyways, thanks a lot for posting and sharing this project. It's super useful!

author: Peter_the_diver
author_rank: Newbie
timestamp: March 19, 2022, 08:25:07 am
content: Hello Guys,I have built and tested a few couples of samples of my design 3.0. Everything works fine. Find attached some pictures

author: Peter_the_diver
author_rank: Newbie
timestamp: March 19, 2022, 08:30:13 am
content: and here some more..

author: Factotum
author_rank: Contributor
timestamp: May 17, 2022, 07:56:50 am
content: Is there a link for the v3.0 PCB and BoM?Cheers!

author: ebclr
author_rank: Super Contributor
timestamp: May 17, 2022, 10:14:49 am
content: I just bought the original chip, From China , let wait to arrive

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 17, 2022, 12:30:23 pm
content: Quote from: ebclr on May 17, 2022, 10:14:49 amOriginal CHIP or Rigol probe for $400?If there is a probe, then you will have beautiful wires.I was offended to buy it for half the price of an oscilloscope, and I also regretted the money.

author: ebclr
author_rank: Super Contributor
timestamp: May 18, 2022, 10:18:50 am
content: I'm talking about the Ti Chip

author: raminrajabi
author_rank: Contributor
timestamp: June 25, 2022, 06:40:01 am
content: Hi,Can I use it for my ds1104z plus oscilloscope?I think my oscilloscope and yours using the same deviceThanks

author: S. Petrukhin
author_rank: Super Contributor
timestamp: June 25, 2022, 07:17:48 am
content: Quote from: raminrajabi on June 25, 2022, 06:40:01 amYes, but you need to take care of the connecting wire to the other connector.

author: raminrajabi
author_rank: Contributor
timestamp: July 20, 2022, 05:29:26 am
content: I think both oscilloscope using the same module, so same connection? Right?

author: vermin123
author_rank: Newbie
timestamp: July 23, 2022, 07:49:04 am
content: For those who are looking for sn65lvds1dbvr -https://aliexpress.com/wholesale?SearchText=sn65lvds1dbvrBut I already bough 6 x sn65lvds391, so will make my board with it...

author: S. Petrukhin
author_rank: Super Contributor
timestamp: July 23, 2022, 07:58:40 am
content: Quote from: raminrajabi on July 20, 2022, 05:29:26 amAnd not only oscilloscopes.This is a common LVDS interface, widely used.

author: JCS666
author_rank: Contributor
timestamp: August 24, 2022, 11:39:48 am
content: I am interested in this kit, does anyone sell it?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 24, 2022, 12:39:39 pm
content: Quote from: JCS666 on August 24, 2022, 11:39:48 amPerconally I can't help you - all logistics from Russia to Europe has been destroyed.But you can order PCB and assembly on JLCPCB or PCBWay, for example. It's not difficult.

author: imolnar
author_rank: Newbie
timestamp: October 05, 2022, 01:22:36 pm
content: Hey guys,I built a version of this DIY LA.My scope doesn't recognize, when I plug it in.The outputs of the DS90.. are fine, but the scope indicates a constant low level.Any advice?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 05, 2022, 04:49:33 pm
content: Quote from: imolnar on October 05, 2022, 01:22:36 pmHow did you check the LVDS outputs? This is a differential signal, it does not need to be measured relative to gnd, it is the voltage between pins 3 and 4 that is needed. It should change when applying 1 to pin 5.If this does not happen, the power supply may not be supplied or the chips are faulty.And it is absolutely necessary to check the flat cable - whether it is properly compressed (it should be 1:1, pin to pin, the keys on both connectors should be in the same position), there is contact on all wires.Did you remember to turn on LA in the oscilloscope?This is a very simple circuit, I'm sure you'll find the fault.

author: mrpea
author_rank: Newbie
timestamp: November 08, 2022, 02:52:37 am
content: S.P,just a quick question, how did you generate the board view for this project? i have been using altium to generate PCB files and have not seen a board view quite like that.. very handy for loading a board manually. i searched easyeda's wiki and didn't see anything..

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 08, 2022, 07:43:31 am
content: Quote from: mrpea on November 08, 2022, 02:52:37 amTo get BoardView and a few other very nice features in EasyEDA, you need to install pragins.Start browsing here:https://easyeda.com/forum/topic/Extension-User-Extensions-for-EasyEDA-Summary-9e065b68316f4491a3911dc6204be31eAltium is too expensive and cumbersome thing, I don't use it.

author: mrpea
author_rank: Newbie
timestamp: November 08, 2022, 10:12:43 pm
content: Thanks for that.. I have been using Altium for the past 15 years, i have tried to use EasyEDA and KiKad, but i keep trying to use the fast keys for Altium.. i really need to do a full project in either to become more proficient.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: November 09, 2022, 12:54:53 am
content: Quote from: mrpea on November 08, 2022, 10:12:43 pmYou can import a project from Altium into EasyEDA and generate a BoardView.

author: imolnar
author_rank: Newbie
timestamp: January 12, 2023, 10:21:40 am
content: Hi,What voltage should be measured on the unloaded ProbeDet pin?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 12, 2023, 10:57:58 am
content: Quote from: imolnar on January 12, 2023, 10:21:40 amApproximately 3.3-5 volts.

author: imolnar
author_rank: Newbie
timestamp: January 12, 2023, 12:13:16 pm
content: 0.4V by me.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 12, 2023, 12:32:39 pm
content: Quote from: imolnar on January 12, 2023, 12:13:16 pm0.58VIf short this pin to GND, "Probe connected" message will show about 3 seconds.

author: imolnar
author_rank: Newbie
timestamp: January 12, 2023, 12:54:49 pm
content: There are no messages on my scope. I can press the LA button, but there is no change in the digit channels.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 12, 2023, 01:11:11 pm
content: Quote from: imolnar on January 12, 2023, 12:54:49 pmWhat is the model of your oscilloscope?

author: imolnar
author_rank: Newbie
timestamp: January 12, 2023, 01:28:40 pm
content: 5074 with patched firmware

author: S. Petrukhin
author_rank: Super Contributor
timestamp: January 12, 2023, 01:36:12 pm
content: Quote from: imolnar on January 12, 2023, 01:28:40 pmAre you sure about the correct cable connection?Pin 1 "Probe detection" is located on the right side in the upper row when looking at the oscilloscope. Connect the two right pins - probe detection.

author: imolnar
author_rank: Newbie
timestamp: January 12, 2023, 01:53:23 pm
content: I hope so. The other signals are in the right place. (4V, +-2.5V, Refs).

author: Peter_the_diver
author_rank: Newbie
timestamp: January 19, 2023, 04:53:10 pm
content: Hallo everybody!I got certain inquiries regarding technical documents of the analyzerV3in the last time. Please find the complete set of design documents here at my websiteeltguy.de.have fun!

author: Swake
author_rank: Frequent Contributor
timestamp: February 13, 2023, 09:26:54 pm
content: Hi Peter and S. Petrukhin,What size are the resistors, the capacitors and the LED in the V3 design? 0805, 0603?The Onsemi MC33375ST-3.3T3G in SOT-223-3 package is not in stock. A suggestion for an alternative would be very welcome.Thanks all for this nice little project, it has a high approval rate of the wallet manager

author: Swake
author_rank: Frequent Contributor
timestamp: February 13, 2023, 09:54:28 pm
content: Have found the XC6203E332FR-G with Quiescent Current of only 8 µA. I think is needs 3.5V on input minimumMax Input voltage is 8V, is that enough? I remember something about 4V input.Different implementation compared to the MC33375ST (no on/off pin for example) this will require PCB change.Alternative is MCP1755ST-3302E/DB with Quiescent Current of only 68 µA. Needs 3.6V on the input minimum.Max Input voltage goes up to 16V. Also different implementation compared to the MC33375ST, but less change required.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: February 14, 2023, 06:32:11 am
content: Quote from: Swake on February 13, 2023, 09:26:54 pmHi, Swake!Version 3.0 was created by Peter_the_diver. I do not know the details.I think it makes sense for you to take a look at the board and the documentation that Peter kindly published on the siteeltguy.de.

author: Swake
author_rank: Frequent Contributor
timestamp: February 14, 2023, 07:24:06 am
content: I see now there is more than one page in the PDF....

author: gharac
author_rank: Newbie
timestamp: February 14, 2023, 08:02:00 am
content: I have built version 3 with a MCP1754. It works and has enough drop-out and mA. However, the middle pin must be lifted because the MCP1754 has no enable pin. Alternatively cut the trace between pin 1 and 2.https://ww1.microchip.com/downloads/en/DeviceDoc/20002276C.pdf

author: Peter_the_diver
author_rank: Newbie
timestamp: February 14, 2023, 09:12:34 am
content: good morning Swake,as Sergei already mentioned, you find the housings in my documentation. Please take look at the BOM (page2).Regarding LDOgharechas described a valid option.

author: NRS63
author_rank: Newbie
timestamp: May 16, 2023, 08:22:02 am
content: QuoteCould you post the design of the box?

author: S. Petrukhin
author_rank: Super Contributor
timestamp: May 16, 2023, 11:09:45 am
content: Quote from: NRS63 on May 16, 2023, 08:22:02 amIt slightly does not match the holes for the connectors, it needs to be modified with a file.I didn't correct it, I'm sorry. If you can do this, please post the correct version here.

author: NRS63
author_rank: Newbie
timestamp: May 16, 2023, 03:04:11 pm
content: Спасибо ! Я кстати собрал плату по Вашим чертежам и все отлично работает ! Детали с Алиэкспресс . Единственно обманули с микросхемой 3.3 в ,прислали обычную 78l33 с маркировкой

author: NRS63
author_rank: Newbie
timestamp: May 17, 2023, 04:29:21 pm
content: Sergey hi! I changed the holes for connectors in the Compass-3D program, I don't have any programs for printing and AutoCAD, so I couldn't save it in the right format.

author: suarezvictor
author_rank: Newbie
timestamp: June 12, 2023, 11:45:33 pm
content: I think a faster way to couple digital signals is by a XOR gate used as a inverting buffer and another as non-inverting buffer, followed by a resistor networks that adapts levelsI designed such a resistor network for signals of 3V (3.3V is similar or also the same circuit will work)Common mode voltage is 1.25V and expected termination 100ohm, for 3.5-4mA (see simulation)XOR gate can be a fast SN74AUC1G86DCKR (1ns propagation delay)

author: suarezvictor
author_rank: Newbie
timestamp: June 15, 2023, 03:35:57 am
content: I was able to detect 1ns pulses (see red trace) by direct connection to LVDS inputs. So that timing can be reached in a probe board using differential inputs buffered by a faster buffer, like SN65LVDS100 (up to 2gbps)Note that same IC can be used for a CMOS to LVDS translator, the one without a termination resistor is much like an analog comparator with a bit of hysteresis (capable of 0 to 4V inputs)

author: andy_edin
author_rank: Newbie
timestamp: August 27, 2023, 04:21:55 am
content: Hi, This looks great - and a much better option that the Rigol probe for my limited needs.I have the DS1104Z Plus scope with the the 68 pin HPDB LA connector. Has anyone tried this design (or the budget MSO5000 probehttps://www.eevblog.com/forum/testgear/ms05000-budget-logic-analyzer-probe-set-design/?all) on this scope ? Maybe there is even a PCB with a HPDB plug instead of the 40pin IDC for the MSO5000 available somewhere ?

author: Andrey_Ak
author_rank: Regular Contributor
timestamp: September 19, 2023, 08:30:55 pm
content: Good afternoon!Please tell me, did you say to take these drivers SN65LVDS1DBVRG4https://www.lcsc.com/product-detail/LVDS-ICs_Texas-Instruments-SN65LVDS1DBVRG4_C50990.htmlBut these won't fit by any chance? SN65LVDS1DBVRhttps://www.lcsc.com/product-detail/LVDS-ICs_Texas-Instruments-SN65LVDS1DBVR_C465731.html??

author: Nikki Smith
author_rank: Contributor
timestamp: September 19, 2023, 08:45:59 pm
content: Quote from: andy_edin on August 27, 2023, 04:21:55 amI've designed an improved (and cheaper) version of the board in KiCad for the MSO5000 (and new DHO900) series. I'd also like to do a version for the DS1000Z Plus series with that 68-pin connector, but I don't have that scope to test it with. Would you be interested in trying an alpha-test board Andy? Thankshttps://climbers.net/sbc/clone-pla2216-logic-probe-analyzer/

author: Andrey_Ak
author_rank: Regular Contributor
timestamp: September 19, 2023, 09:06:13 pm
content: Quote from: Nikki Smith on September 19, 2023, 08:45:59 pmI like this option. I would try to order the manufacture of boards for myself.Only the drivers are not on salehttps://www.lcsc.com/search?q=SN65LVDS391PWRhttps://www.lcsc.com/search?q=SN65LVDS391D

author: Nikki Smith
author_rank: Contributor
timestamp: September 19, 2023, 09:46:54 pm
content: Quote from: Andrey_Ak on September 19, 2023, 09:06:13 pmNote that I'm still working on the design, and the boardshaven't been tested yet!LCSC are temporarily out of stock (I got some last week), but I've just checked and both chips are in stock at Digikey, Mouser and RS for a similar price to LCSC.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: February 02, 2024, 09:37:56 am
content: The discussion of the oliver probe option has been moved here:https://www.eevblog.com/forum/testgear/another-low-cost-la-probe-for-rigol-mso5000-by-oliv3r

author: oliv3r
author_rank: Frequent Contributor
timestamp: February 03, 2024, 02:44:17 pm
content: Super!! Thanks for whoever did itI think we're all happy now.

author: Peter_the_diver
author_rank: Newbie
timestamp: July 02, 2025, 07:47:45 pm
content: Hallo again guys!As extention to my Logic Probe 3.0 I have designed a 1:3 pre dividor. This enables you to process signal levels of up to 15V with the Logic Probe. If you are interested, please take a look here at my Websitehttps://eltguy.de/selbstbauprojekte-elektronik-technik-hobbytechnologien/logic-probe-ein-digitaler-16-kanal-tastkopf-fuer-oszilloskop/. You can download the relevant design documents there.

author: gentilkiwi
author_rank: Newbie
timestamp: August 16, 2025, 08:53:47 pm
content: When reading all your posts (thank you for them) - just saw that the SN75LVDS driver is for 100 ohms ended.It seems that, on the MSO5000 side, it's already terminated with 33 ohms resistors - see picture ( fromhttps://www.flickr.com/photos/eevblog/44893167835/in/album-72157701904033821)Isn't the best option to NOT populate 100 ohms resistors on PCB side? (to avoid worst result than with 33 ohms)(maybe a newbie mistake, sorry for that)

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 17, 2025, 02:07:23 am
content: Quote from: gentilkiwi on August 16, 2025, 08:53:47 pmIn the MSO5000, 33 Ohm resistors are installed in series.I think it's just a protective function and to suppress EMI.If you remove the 100 Ohm load, the SN75LVDS will be very upset because it tends to maintain current.The termination resistors should have been inside the MSO5000, but they weren't there. However, the terminator also works well on the other end of the line.

author: gentilkiwi
author_rank: Newbie
timestamp: August 17, 2025, 10:50:05 am
content: Quote from: S. Petrukhin on August 17, 2025, 02:07:23 amAs I don't want the LVDS to be upset, I will try to keep them soSorry to made you verify, and what a strange design on the MSO side :')

author: gentilkiwi
author_rank: Newbie
timestamp: August 18, 2025, 08:52:30 am
content: I made 2 variants base on JLCPB capabilities for PCBA (I'm not good for that)>https://oshwlab.com/gentilkiwi/mso5000_lpThe first one is based on the SN75LVDS387, and the second one on 16x SN65LVDS1

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 18, 2025, 11:36:08 am
content: Quote from: gentilkiwi on August 18, 2025, 08:52:30 amThis design looks better than mine, and I think it's preferable.

author: gentilkiwi
author_rank: Newbie
timestamp: August 18, 2025, 12:14:27 pm
content: Ho, I still not respect tracks lenght... just made it because components available and because I prefer the right angle connector for probes (because of Saelogic connectors compatibility) even if it costs more space on the board !May also consider XC6206P332MR-G for the LDO, as it's low ESR & it's 'Basic PCBA'

author: S. Petrukhin
author_rank: Super Contributor
timestamp: August 18, 2025, 08:28:03 pm
content: Quote from: gentilkiwi on August 18, 2025, 12:14:27 pmIt is correct to align the length of the differential lines, but Rigol engineers did not take care of this, and practice has shown that it still works stably. I used this at a frequency of 84 MHz and observed a small jitter that did not interfere with comfortable operation.