New answers tagged

0

Another option you may consider is control+drag the component away from the nets you have it connected to. Pressing control will cause it to not drag the nets with it. Once you have the component by itself, press Y to flip it on the Y-axis. Then drag it back to the original location. This assumes symmetry in the component so that once flipped it will still ...


3

You'll have to rewire the component from the schematic if you want to uncross the wires. If you want to rotate the part then use 'space'. You can also use 'X', but that probably won't do what you want either.


2

Asking pros and cons of Bare dice vs packaged parts is like asking the pros and cons of buying a house versus flying an airplane... The circumstances where a bare die is appropriate are very different from PCB design. This is really a design project for a certified Professional Engineer, not an internet Q&A. There are legal and ethical obligations as ...


2

I believe you just need to make sure all your polygons are overlapping (to make sure they are connected) and then drop down a small pad anywhere within the polygon. Is this what you're looking for? https://www.altium.com/documentation/altium-designer/working-with-custom-pad-shapes-ad?version=18.1


1

Samtec has the LSXX parts, other vendors have similar horizontal connectors. You should take into account all the creative ways your users can connect the boards.


0

While the alternatives you're considering will affect the performance slightly, the differences will be small. On the signal splitter, there's not a lot you can do about that triple pad in the middle, it's probably as good as it can be without proper design as it's shown. You could probably improve the performance slightly with some detailed modelling and ...


2

Vio is the supply for external interfaces of a chip. It may be separate from the core supplymerely for electrical integrity purposes related to having enough supply pins near the load. But often it is separate because the I/O bank will or could run at a signalling different voltage from the core. If you intend to communicate via 3v3 signalling, something ...


15

Hermaphroditic connectors. Most I see are vertically hermaphroditic though and you seem to want horizontally hermaphroditic. Note you can turn the board upside down and plug it in the wrong way, though you can do that in your original image too. With regards to reducing BOM count, most hermaphroditic connectors seem to be vertically hermaproditic (like ...


1

Beside what is already said in comments, BGA has the disadvantage, its hard to replace the IC by hand (but possible) Advantage is, HF Signals like High speed busses can be guided directly from under the pin by special vias into the inner layers, which from impedance is much better than with QFN. Its a good Idea to do a raw routing concept for both and see if ...


0

It looks like the terminology is not yet settled. In this article the groove cutting by a laser refers to the "positive and negative depth control method". I think that your slot method based on gluing the finished flex layer to rigid layers. And your window method based on pressing layers all together, followed by contour milling and window ...


0

I am under the impression that a lot is going wrong in this design... The guard ring impedance was already mentionned by @sbell. It has to be at the same potential as the signal that you are protecting AND it must be sufficiantly low impedance to catch any current coming from outside the guard ring. The output of your opamp is not at the same voltage syou ...


1

Draw a proper circuit diagram. Sketch out an appropriately sized board (one that will hold all of your parts and leave enough room for connectors and traces.) Place parts on the PCB and arrange them so as to minimize crossed traces. Make sure the parts will physically fit around each other as you have placed them. Route traces to connect your parts and ...


-1

EasyEDA is a free, web-based service for circuit design that is oriented towards beginners that want to design a circuit board without necessarily having a lot of design experience or understanding of traditional EDA tools: https://easyeda.com/ They also partner with board houses, which simplifies ordering if you are not familiar with the process. While I ...


-1

PCB design is extremely broad topic. Just transferring connection from a breadboard to PCB is easy but Stackup selection, signal integrity, Design for testing, design for manufacturing and certification is completely different thing. There is no one book to cover all of those aspects. Only answer anybody can give you here is which options you have for tools. ...


1

The guard needs to be a low-impedance potential in order to protect what it is surrounding. Using a capacitive-divider like you have is ... not great. To generate a low-impedance mid-scale reference, use a resistor-divider between +VCC and -VCC, and then bypass that with a capacitor to -VCC to filter out noise, and buffer that with a low-noise op amp: ...


6

In your image, FIDU is the symbol's name for fiducial. Fiducials are used by optical equipment (a pick and place machine) to visually see and locate the board's origin relative to the machine's origin. A small fiducial is probably a 1 mm diameter footprint. Typically, I would place 3 on the top-side of the PCB near the corners and 3 for the bottom-side. I ...


3

"Fidu" is short for fiducial marker. They are used on printed circuit boards (PCB) to assist in lining up the various layers.


1

I would guess it refers to Fiducial Marks, measuring points on PCBs for positioning.


2

If that is what I think it is, it is a Fiducial. They are used for the board manufacturer as a reference so that they know where everything is located on the board coordinate-wise. If you want to learn more about them, there is plenty of information online if you look up ‘Fiducial’.


0

In applications where there is risk of noise from the SPI CLK - I have used a multi in/out MUX IC for attaching multiple devices to the same bus. The MUX will act like a pass transistor. At higher SPI frequencies this may be harder to achieve due to impedance matching.


1

Could you help check any mistakes in my PCB layout and routing? No, can't check that none of the parts on the red side are labeled. but you should keep everything away from the antenna area, ideally even the board. Some parts seem to have too few connections. some of the joins between traces are too sharp Other than that it's hard to say.


1

I would move the component with the light-green arrow and in dark-green I have added my take on cleaner routing. Set a rule to have thermal reliefs of atleast 10mil, altough I use 20mil when possible. Add teardrops (Tools->Add teardrops). You also need to add a Polygon and connect that to GND. For best practice, add the polygon on the top and bottom. ...


1

Try with small current up to 3 - 5 mA for two polarization. Such current not destroy your LD but this allow you to see weak lighting of the diode for one of the polarization wchich is correct.


0

What you need is freezer spray... you get it at every better shop for electronics stuff like https://www.conrad.com/p/toolcraft-tc-kc400c-tc-kc400c-freezer-spray-non-flammable-400-ml-887253


0

Yes, the is an aerosol spray made for this purpose. Google “circuit chiller” or search your favorite distributor like Digikey or Mouser under the chemicals category.


0

Beyond the obvious advantage of having a dedicated ground plane and power plane (The two additional layers are used mainly for that purpose), it makes routing traces much easier. Practically you don't need routing for ground and power. Only signals have to be traced. If the device is not high frequency or ultra sensitive, you can use the power plane and to a ...


2

I would like to jump to 4 layers pcbs, but everytime that I've looking in Google information, it's much complex than 2 layers. Impedance tracks, resistance of the tracks, decoupling capacitors for some impedance, EMIS, and the stack of course. I know this concepts separately, but when I'm designing I don't really know much more than the datasheet can tell me....


0

From my experience, for rf circuits, use layer 2 as ground plane and layer 3 as supply plane assume rf components are placed on layer 1.


2

If you have the board in your hand, it's too late. Even before or without simulation, you will have prototyped the riskiest parts of the circuit and know how they work and what to test. The less risky parts are less risky because you already know how to test them. Therefore you already have a test plan that enables you to test that the board matches the ...


0

Summary: For typical heatsink profiles that are not used at the extreme of device failure mounting on an edge is non-ideal but will work acceptably well. This is commonly done commercially. For heatsinks with long thin thermal paths applying heat at the geometric centre will produce significantly better results - but, the design is in any case sub-optimum. ...


2

So you went through weeks of schematic design and PCB layout design and Sent files over to fab house. Now, you got the PCB from FAB house. Basically you learn from your mistake. That mistake is: don't ship any design out to a PCB manufacturer without simulating the circuit to death and re-fixing the schematic/PCB as you find design/performance/functionality ...


-3

A high-frequency Printed Circuit Board can meet your needs when incorporating a special signal requirement into your electronic components and products. It offers a frequency range of 500MHz - 2GHz, making it ideally suited for high-speed designs, as well as radio frequency (RF), microwave and mobile applications. These higher transmission frequencies can ...


1

When I do a probe of the voltage with a scope across C1 the voltage read out is 5v instantly That might be a problem if you are using an earthed scope and your signal generator is also earthed on its return wire. Instead, try probing the drain of Q1 and the top of C1 with two probes and subtract the voltages. $$\boxed{\text{OR}}$$ C1 could charge instantly (...


0

I suggest you use a bridge rectifier for reverse voltage protection and a zener clamp circuit to protect from over-voltage.


3

So, Orcad files are, to my knowledge¹ not text files, but binaries. That makes it harder for typical source versioning software to track changes. However, having a version history of your files is still better than having to manually make copies – as long as you know which files need tracking. Git does all that – I'd recommend looking through section 1.3 (...


1

Someone once told me that anyone can build a bridge that stands. But it is much harder to build a bridge that "barely" stands. Engineering is all about trade offs and making something that is good enough. As the surface area shrinks it can lead to more issues with signaling. Most designers will spend more time on part placement to try to minimize ...


1

As other answers mentioned the light parts are usually not a problem. For heavy parts there is special heat curable adhesive that will ensure that those stay in place. Adhesive can be placed either under the component if there is no bottom pad or can be placed at the corners (for BGA components). Good SMA house will have machine that dispenses adhesive. For ...


0

It may also have a lot to do with Rev 1 vs Rev 2. Your example BFU730 (2010) vs Rev 2 BFU730F (2012), which I'd guess as 6 actual internal revision. Until it has been prototyped and tested, engineers will err on the side of caution to combat issues the other answers have described. As they identify, simulate and correct issues the design will change. From ...


2

Many assembly houses can do this and have different methods. A cheap and dirty way to do this at home would be to use different solder materials with different melt points.


1

The PWM frequency might be 5.6MHz but that doesn't mean it will actually turn ON and OFF LEDs at 5.6 MHz. Also, PWM having a PWM frequency that high in your application is also very unlikely. Basically your PWM will get converted to average DC value and that will drive your LEDs. Coming to your question about placing extra layers on top and bottom of PCB, ...


1

We used to do reflow on top and then wave on the bottom. On the bottom side, the pick and place machine would stick the components down with glue. The solder wave would do both the SMT and the PTH. I don't remember the specifics but when we moved to double-sided reflow (to support BGA devices) there was some sort of upgrade that went on in the factory.


2

The correct answer is to check with whomever is doing your SMT assembly and ask them. Double-sided boards are very common. But your own vendor has to be setup to do it.


9

No, it’s generally not a problem. You can solder the light parts first and then flip it and solder the rest. The surface tension of the solder will hold small parts onto the board. In the unusual case where you might have a heavy part or two on the bottom on the second cycle you can add adhesive or solder it later by hand. 'Heavy' relates to the relationship ...


2

It is done as you mentioned using adhesive tape on already soldered side. Also, components should be selected carefully and heavy component should be put on 2nd side if possible. [EDIT] : My mistake only some low cost operations do the tap on bottom side to support heavy parts. Typically reflow profiles is carefully curated and SMT JIG is used after one side ...


11

It appears that there is no soldermask on that board at all, and the opening you are referring is in the copper. When it comes to RF or other high-frequency signals, surrounding objects play a large role in the impedance of the line. If you have copper surrounding the microstrip trace(s), the impedance will be affected. Besides this, signals travelling on ...


4

Hm, couple of things: "reference design" == "best performance" isn't usually what you need. You need adequate performance, and that might be achievable using smaller layouts. Also, you might have been looking simply at different ICs for other markets than highly integrated designs. I find that nowadays, IC manufacturers put a lot of ...


3

Unreliable traces are usually a problem with the PCB itself, not caused by soldering. So, review your PCB production data (Gerber files) and make sure the copper of that traces continues under the ring of the via. Look at the ring of a board that's not soldered with a strong magnification (microscope?) to see whether there's anything suspicious. Also, look ...


9

Because at RF, solder mask behaves differently than air; especially, it has higher losses. Also, yes, even if it was lossless, the materials below and above the microstrip affect the wave impedance. However, one would be able to counter that by changing geometry of the line. Does it have something to do with avoiding to change the characteristic impedance ...


5

Those large foil layers become magnetic shields for frequencies faster than about 1MHz (just a few dB reduction), with 4MHz getting 9dB (1 neper), 40 MHz getting 27 dB (3 nepers), 160MHz (typical MCU edge speed or VDD ringing) getting 50--60dB attenuation, and 400MHz (sub_nanosecond edges) getting 80--90 dB attenuation (10 nepers or 90dB). One way to cause ...


1

So it did turn out to be a power supply issue. I used 2 18650 batteries instead of 1 in a parallel holder. Dont worry, I made sure to balance them before putting them on. I connected the charging board to the circuitry of the original coupler. I set the incoming voltage to 3.7 for the coupler. And it outputs 8v to the dummy. It turns on for the most part and ...


Top 50 recent answers are included