hybridfree/eevblog-posts huggingface dataset:
USB Host to USB Device on PCB no connectors - Page 1
Forum section: electronics / projects

author: veryevil
author_rank: Unknown
timestamp: July 05, 2011, 11:47:29 am
content: Hi, Currently working on a project where we are connecting an AT91SAM9G20 to a Sierra Wireless SL8082 UTMS (3G) modem. We wish to use the USB interface as this opens up 4 UART interfaces from the modem.However I was wondering how to design the PCB as they will be connect directly on the same board without any connectors. Does a USB interface need any components between the two if not connector is used?Thanks

author: Decap_dk
author_rank: Newbie
timestamp: July 05, 2011, 08:46:23 pm
content: HelloYes you should be able to route the connection of a USB host directly to a USB device. Only keep in mind that ideally you should route them as differential signals with an impedance of 90 Ohm. If your traces are not to long don't worry to much about this but keep the positive and negative signal together.RegardsDecap_dk
USB HSETT issues  - Page 1
Forum section: electronics / projects

author: PeterF
author_rank: Contributor
timestamp: April 06, 2018, 08:45:09 am
content: Hey guys,Perhaps this is a much too boring and professional-related topic, please let me know if it does not suite this forum.I have two laptops, one is a lenovo and another is a HP elitebook.I am trying to run the USB xHCI HSETT (the usb high speed test tool which is used for USB testing. In my case, I want to put devices in test mode).On my Lenovo, I got it working.But on the HP, I just can't find any controllers..I have found the connected device using usbview and I am pretty sure it is on a xHCI bus.Does anyone have experience with getting this to run, and do you have any tips on what to test? (I have disabled UAC, and am running an admin account)

author: abyrvalg
author_rank: Frequent Contributor
timestamp: April 06, 2018, 05:34:22 pm
content: I had experience with some (don’t remember which exactly, it was several years ago) USB compliance tester from usb.org and it was clearly stated that it will work on some specific host controllers only because of some non-standard mode it was using. It was replacing the hc driver with it’s own at start and reverting back to the original one at the end.I would advice comparing the host controller makers/models (not just xHCI/other) of both PCs.
USB hub I designed keeps failing. Can somebody look at my design please? - Page 1
Forum section: electronics / projects

author: 4flyer
author_rank: Contributor
timestamp: March 14, 2023, 03:00:42 am
content: I recently designed a US hub based around he USB2507. I am having an issue where when I power up the IC with 3.3, it seemingly dies and gets very hot and draws 200mA more than it should. I have even removed my 3.3V LDO and powered the IC directly from a power supply. I think I did a decent job on the board minus some impedance mismatches on the USB lines. Regardless, this issue is present even when all I have powered is the USB IC and its associated capacitors. Do I have something wrong with the schematic? Could bas capacitors cause the IC to fail? Attached is my schematic and datasheet. I am also attaching the demo board schematic provided by the vendor. Thanks for the help!

author: ajb
author_rank: Super Contributor
timestamp: March 14, 2023, 04:05:24 am
content: Just at a quick look, the PRTPWR pins are outputs meant to control power to each downstream port, but you've got them strapped to +3v3. There may be other issues but that could certainly cause the problem you're seeing

author: pcprogrammer
author_rank: Super Contributor
timestamp: March 14, 2023, 07:11:49 am
content: Another thing in your schematic that can give problems is the direct connection between the two host supplies. Not the reason for the board not working. That is more likely due to what ajb wrote.Why the direct connection of the two host supplies can be a problem has to do with USB supplies coming from different computers not being at the same voltage level. By the looks of it you are only using it to detect if a host is connected, I would at least add diodes in series. But since you are using a switch to select which host is being used it would be cleaner to add some logic, that only the supply of the selected host is fed into the detection pin of the USB2507.

author: 4flyer
author_rank: Contributor
timestamp: March 15, 2023, 02:25:50 am
content: Quote from: ajb on March 14, 2023, 04:05:24 amThis was the issue. Thanks for the help! You are a life-saver!
USB Hub IC Schematic Check - Page 1
Forum section: electronics / projects

author: mastermaker7000
author_rank: Newbie
timestamp: July 18, 2025, 03:27:20 pm
content: I am using this USB2514B IC to access two USB devices (Cypress FX2 and FT2232) on my PCB with just one USB C port. I followed the datasheet the best I could but I have never used a usb hub IC and want to make sure I know how this works.For example, I need USB high speed, but for the pin strapping configuration, I must pull the CFG_SEl1 / HS_IND pin low according to the datasheet. Would this not disable high speed since I am pulling HS low?The non_rem and cfg pins are confusing me and I need help to make sure I understand them correctly.Here is the datasheet:https://ww1.microchip.com/downloads/en/DeviceDoc/00001692C.pdfI have attached a picture of my schematic below.
USB ID pin voltage - Page 1
Forum section: electronics / projects

author: gaminn
author_rank: Frequent Contributor
timestamp: August 18, 2019, 06:33:55 pm
content: Hi,I'm designing USB device which will control ID pin to tell USB host (tablet) whether the USB host should supply 5V on the bus (ID pin shorted to ground) or whether there is externally supplied 5 V on the bus so the host can charge itself (ID pin connected via xx kOhm resistor to ground).Is there any specification what voltage will USB host use to sense the ID pin? Is that 5 V or 3V3?

author: Renate
author_rank: Super Contributor
timestamp: August 18, 2019, 06:54:32 pm
content: It's generally presumed that what is presented to the ID pin is a pure resistance, in the simplest case open or shorted to ground.I've seen OTG hosts that use a simple 3.3V GPIO input pin with the SOC pullup resistor.I've seen OTG hosts that use an ADC and a current source or pullup.I think that some of those are always on and some of them are pulsed and polled.Support for random values of ID resistances is varied.Support for OTG peripherals powering the host is variable too.
USB Isolation/Protection - Page 1
Forum section: electronics / projects

author: aiq25
author_rank: Regular Contributor
timestamp: February 25, 2015, 04:51:15 am
content: Hello. I was looking to built a USBtin device (it's a USB-to-CAN device) and looking at the schematic there is no isolation between the USB and the micro-controller (PIC18F14K50). I also don't see any type of transient protection on the USB or the CAN. I have designed a circuit before with a CAN transceiver and we put in a common mode choke, capacitors and ESD diodes.I plan on modifying the circuit for the USBtin to include a common mode choke, capacitors, and ESD diodes for the CAN bus. But I was wondering what type of circuitry should I (or can I) put to protect the USB port. I was thinking of maybe using something like the TI ISO7221C chip but I don't know if complete isolation is really necessary. Ultimately it would be nice to power the board through USB. Would ESD diodes and capacitors be enough protection for the USB port to be protected?Any help suggestion/feedback is greatly appreciated.

author: aiq25
author_rank: Regular Contributor
timestamp: February 25, 2015, 05:46:56 am
content: Okay just read through some application notes for USB protection. Looks like I should have some ESD protection diodes, along with capacitors/diodes for transient and possibly a common mode choke for EMI suppression. Since I'm planning on making this thing using a breadboard might be tricky to find ESD protection devices as through hole component (not sure though, will look in the morning).

author: mathias
author_rank: Regular Contributor
timestamp: February 25, 2015, 06:40:04 am
content: Analog Devices makes a USB isolator, ADuM4160 and power isolator ADuM5000.Because you say CAN, I'm thinking automotive or industrial, so perhaps these can provide a nice buffer should something go terribly wrong. Then again, they cost 10 EUR/$ each, so that adds quite the cost to your project.

author: wreeve
author_rank: Unknown
timestamp: February 25, 2015, 06:46:23 am
content: AD also make the ADuM3160 which I have used in many designs; it also does power and allows you to disconnect via software (i.e. pin!).

author: Psi
author_rank: Super Contributor
timestamp: February 25, 2015, 07:02:55 am
content: You are "supposed" to have ESD protection on USB, but lots of people don't bother.I've never put any protection on the USB->IC connections and never had any problems. Just a direct connection between USB socket and FT232RL (they even show it that way in the datasheet and the chip doesn't mention any ESD protection built in)

author: aiq25
author_rank: Regular Contributor
timestamp: February 25, 2015, 02:27:33 pm
content: Quote from: Psi on February 25, 2015, 07:02:55 amLooking at the datasheet (didn't really read it much) for the PIC18F14K50 micro it seems like they don't show any type of protection components, just a direct connection to the USB bus. I guess I won't add any.
USB isolator board for testing (chip) - Page 1
Forum section: electronics / projects

author: KedasProbe
author_rank: Frequent Contributor
timestamp: March 26, 2013, 09:23:46 pm
content: Anyone using this?I ordered myself one for separation and easy testing between Desktop PC and PCBs.(No, I'm not using it to evaluate the chip)http://www.analog.com/en/evaluation/eval-adum4160/eb.htmledit: FYIhttp://www.digikey.com/videos/en/v/ADuM4160-First-Single-Package-USB-Isolation-Solution/2196710147001

author: marshallh
author_rank: Unknown
timestamp: March 26, 2013, 10:45:10 pm
content: Full speed only. Won't support 480mbps

author: Circuitous
author_rank: Unknown
timestamp: March 26, 2013, 11:01:18 pm
content: I've built an isolator using the cheaper ADuM3160 (lower isolation rating). It's easy to build, and works just fine... but not for high-speed, only 1.5 and 12 Mbps. That's fine for most of my stuff.The main issue I found was providing high enough current to some USB powered devices. The matching ADuM5000 only provides 100ma (I think), so you may want to use a separate wall-wart to power such devices.

author: KedasProbe
author_rank: Frequent Contributor
timestamp: March 27, 2013, 07:52:50 am
content: I don't mind no 480Mbps support because I can't debug that anyway, my to be used MCU doesn't even support 480Mbps.Yes power needs to be added but I didn't expect to use it otherwise, the board seems to be easy to setup whatever you want. (except 480Mbps)

author: penfold
author_rank: Frequent Contributor
timestamp: March 27, 2013, 08:25:25 am
content: I've not used it, but given the comparative cost of most other isolated usb hubs and adapters can't be too far wrong.The speed is a bit unfortunate, but as a quick and dirty isolator I'll be getting myself one, let me know how it goes and thanks for the tip

author: mazurov
author_rank: Frequent Contributor
timestamp: March 27, 2013, 06:36:09 pm
content: I've been making one based on the same IC for ~3.5 years ->https://www.circuitsathome.com/measurements/usb-isolator. Take a look at the articles/comments for insight.

author: KedasProbe
author_rank: Frequent Contributor
timestamp: March 31, 2013, 06:40:43 pm
content: Seems I already blown my board, not sure what went wrong.Everything worked, then I wanted to use the earth/mass connection of my probe to reduce noise. So I connected it to the mass of the board (mass of my 5V power supply)It was OK, I wanted to reconnect it for a better connection and then it 'shorted' out somehow.Now it only measures 1.67 ohm over C4.The other (identical) side of the chip is still measuring fine.Maybe connecting the ground of my power supply to my scope earth generated unexpected spikes....Luckily it won't cost much to replace the chip. (if that is the problem, and C4 isn't broken)
USB joystick project for PC/PS3 - Page 1
Forum section: electronics / projects

author: terriea
author_rank: Contributor
timestamp: January 23, 2011, 06:40:45 pm
content: Hi eevblog folks,I'd like to share with you this little project i'm working on. It's my first electonic project, and my first video (a lot of first times here). The project is not finished yet, but it's almost working. I managed to get there with the help from the people from eevblog forums so i'd like to thank them a lot.I did my best for the quality of the video with what i had in hands, but when you combine some bad english, with a camera that does not auto-focus and a microphone that looses the sound then you move by a few cm (and someone who heavily breathes in it). Can't really expect wondersAt last, i hope it will entertain you a little.S3YyYpkN1TM

author: sonicj
author_rank: Frequent Contributor
timestamp: January 26, 2011, 10:08:43 am
content: congrats! thats quite an accomplishment for a first project! good luck getting the joystick working right, its probably something simple...-sj
USB layout in top or middle layer - Page 1
Forum section: electronics / projects

author: tiraxinas
author_rank: Newbie
timestamp: April 28, 2022, 12:25:52 pm
content: Hi,High-speed signals routed in the internal layers with GND planes in the adjacent layers have better signal integrity.1. The USB signals from the top layer to the internal layer using vias. How can be sure that the vias don't create EMI reflections?2. When is better to route USB signals in external layers instead of internal layers?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 28, 2022, 04:57:59 pm
content: Which USB version are you targeting?USB1.0/1.1+ "Full Speed" is basically LVCMOS logic level, signal quality is almost irrelevant. It's differential mainly for benefit of poor quality cables; note that no USB is fully differential, on account of the start/stop symbols, so these still need to come through with adequate fidelity.USB 2.0+ "High Speed" is more stringent, but also not terrifically fast (480Mbps) so can tolerate mismatched impedances, stub lengths, etc. up to a modest margin (some cm, say). Easiest: put the PHY right beside the connector, no problem. If a longer route is required, then consideration of signal quality is worthwhile: matched length traces, characteristic impedance, minimize sharp corners and vias.USB 3.2+ "SuperSpeed" (5Gbps or more) requires much more care. Although, are they also doing convenient line coding tricks to help out with that (line or loss compensation, echo cancellation, etc.)? I don't know, I haven't been keeping up with it. This will require matched impedances even for short lengths, keeping stubs to a minimum, etc.In all cases, I think the stub length of a single via is not enough to cause concern. Impedance tolerances likely aren't tight enough to require special fab.But yeh, it's all in the standard, freely available, check it out. You don't need to take our word for it, get it from the source.As for the shielding effect of inner routing (stripline), this isn't necessary to meet most commercial EMI requirements. It may be required for more stringent, medical related?, or say aerospace or MIL standards, or say, the use of a conductive (shielded) enclosure and appropriate grounding measures.Tim

author: tiraxinas
author_rank: Newbie
timestamp: April 29, 2022, 07:30:50 am
content: Hi,Thanks Tim for the answer.We are using USB 2.0 (high speed).If I use the top layer to route the USB communication and the adjacent layer is the GND plane most of the energy is between traces and GND and the rest will be around the signal. Then this signal is not shielded so can the radiation from outside disturb the signals?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 29, 2022, 11:24:12 am
content: What level of immunity are you targeting? I think I would start to be concerned for levels above 10 V/m.Tim
USB Light - Page 1
Forum section: electronics / projects

author: mys_721tx
author_rank: Contributor
timestamp: May 30, 2016, 09:21:07 pm
content: Hello folks!I am working on an USB light. Since I majored in biology in college, my knowledge of electronics is very limited (not much more than basic physics). So, please kindly point out if anything I did wrong.After watching's review on an USB light, I decided to design one as a practice.Because currently I do not know how to make a I decided to use a MAX1555 charger off the shelf. Perits data sheet, when VBATis 3.3V and VUSB5V, the charging current is between 80mA to 100mA. Therefore I choseMLBAWT-A1-0000-000WDTsince its forward voltage is 3.3V and is rated to work between 80mA and 100mA. All the decoupling capacitors are within 1cm of their corresponding pins per data sheet requirement.

author: ebclr
author_rank: Super Contributor
timestamp: June 01, 2016, 05:56:11 pm
content: If you don't like to reinvent the wheel, done for less than a dollarhttp://www.aliexpress.com/item/Portable-Hot-Sale1Pcs-Mini-White-USB-Power-5V-LED-Night-Light-Pocket-Card-Lamp/32659684154.html?spm=2114.30010308.3.135.ouO0wX&ws_ab_test=searchweb201556_8,searchweb201602_4_10037_507_10032_10020_10017_10021_10022_401_10009_10008_10018_101_10019,searchweb201603_3&btsid=8a355870-852c-4acb-88cd-75944e08c790

author: mys_721tx
author_rank: Contributor
timestamp: June 01, 2016, 06:06:29 pm
content: Thanks for the head up, ebclr!The purpose of the project is to reinvent the wheel. As you pointed out, the market is probably saturated with similar products. It would be hard to make this particular design with a competitive budget. Hence the project itself is strictly on paper.

author: NiHaoMike
author_rank: Super Contributor
timestamp: June 02, 2016, 02:56:50 am
content: If you want a challenge, look up "V-USB" and make it controllable from software! Using the charger chip as a LED driver is way overkill - USB is regulated well enough for a simple resistor to work well. PWM it with a transistor if you choose to make it controllable from software.

author: TheDirty
author_rank: Frequent Contributor
timestamp: June 02, 2016, 03:36:20 pm
content: I'm assuming C2 is a decoupling cap. It should be between the IC pin and the power source. Having it branch off and put further up the pcb reduces its effectiveness.

author: edavid
author_rank: Super Contributor
timestamp: June 02, 2016, 04:08:25 pm
content: What would you do with it? It would be much too bright to look at, so I don't see how you could use it if it were plugged straight into a USB port. Wouldn't it make more sense to put a female connector on it?Also, the IC and LED would be hot, so you would want some kind of handle.
USB Logic Tool Kit - Page 1
Forum section: electronics / projects

author: gcp6ca
author_rank: Contributor
timestamp: August 12, 2012, 01:59:28 pm
content: I made this kit and I thought I would share since others may find it useful and maybe improve it further (there are functions I want to add but not really had the time to do):http://www.libstock.com/projects/view/320/usb-logic-tool-pic18f14k50-in-mikrobasic-mikroc-mplab-c18The device is meant to be a prototyping aid and designed to work well by minimizing breadboard space used, interaction through a visual interface, easy setup and low cost. The low cost allows it to be built at home or a PCB can be purchased for a low price. It is also reprogrammable through USB so other functions can easily be loaded (such as a Virtual COM Port) or a custom one (variable switching mode power supply).If you try it out then let me know how useful you find it. I also have a bunch of extra working prototypes if anyone feels they want to buy them instead of making it themselves.
USB memory recovery - Page 1
Forum section: electronics / projects

author: eripaha
author_rank: Contributor
timestamp: January 02, 2014, 06:24:52 pm
content: I am learning to repair badly damaged USB memory sticks. So far i have replaced damaged USB connectors and been able to read data off even USB sticks with pcb broken.As long as the NAND chip is not damaged is it possible to lift the NAND chip with rework heat gun and place it into to another identical donor memory stick?Can you identify the smaller chip in these pictures?I plan to try this out with two of my Kingston DataTraveler 100 G2 8gb sticks if there is no fundamental problem in this.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: January 02, 2014, 06:35:01 pm
content: Should work unless the control chip has some of the bad-block map stored in it.

author: marshallh
author_rank: Unknown
timestamp: January 02, 2014, 07:35:11 pm
content: Like you say it should work in theory but I've attempted that twice with exactly identical pcbs/controller chips with no luck. Might be more to this than I know.

author: codeboy2k
author_rank: Super Contributor
timestamp: January 02, 2014, 07:47:33 pm
content: I have no specific knowledge, but I would think that the bad block map is stored on the flash memory itself, but the controller only stores the block number (or page) of the bad block map (which is determined at first power-on). This allows identical firmware to be flashed into the controller, and it can scan the NAND flash that was assembled into the board and find a reliable area to store the bad block map itself.Then the firmware can report back if it found 1G, 2G, 4G or 8G of good memory.However, in this scheme, after first power-on, the NAND and the controller are now married.

author: homebrew
author_rank: Frequent Contributor
timestamp: January 02, 2014, 09:49:10 pm
content: Yes, it can work.I have done exactly that procedure with a broken USB stick. It worked perfectly!I didn't even had a rework station, I had to use an ordinary heat gun and a temperature probe ...The guy who gave me that stick wanted to get the data back but refused to invest a lot of money into a professional service.Whether or not you should try such procedures depends on the value of the data ...Cheers,Peter

author: amyk
author_rank: Super Contributor
timestamp: January 03, 2014, 10:21:39 am
content: Quote from: eripaha on January 02, 2014, 06:24:52 pmSSS 6696http://www.usbdev.ru/files/sss/http://www.3system.com.tw/en-global/product/productDetail/60#There isn't much info on it, but for some reason the Russians seem particularly interested in playing around with USB drives... as you'll see if you Google "SSS 6696". The controller does have internal flash and firmware so it might not be as easy as a chip swap.
USB operation - Page 1
Forum section: electronics / projects

author: Lambros
author_rank: Newbie
timestamp: March 12, 2013, 05:05:13 pm
content: Hey, there everyone.Can anyone give a link to a thread that explains the function thoroughly of a USB memory drive when it communicates with a PC?Thanks

author: ve7xen
author_rank: Super Contributor
timestamp: March 12, 2013, 05:21:17 pm
content: The USB spec is freely available here:http://www.usb.org/developers/docs/usb_20_110512.zipIt's highly non-trivial, especially if you want to think about partitioning, filesystems and any other layers on top of USB - but even USB itself is a pretty complicated system.USB in a nutshellis the best overview of the bus I've seen, but it barely scratches the surface of how an actual device functions.

author: Lambros
author_rank: Newbie
timestamp: March 12, 2013, 05:23:19 pm
content: Thanks

author: Smokey
author_rank: Super Contributor
timestamp: March 12, 2013, 07:59:22 pm
content: Check out Travis Goodspeed's projects. His current one is emulating flash drives in software using a sort of USB spoofing device he built. His stuff is really interesting. The youtube videos of his conference talks are great too.http://travisgoodspeed.blogspot.com/

author: Icarus
author_rank: Regular Contributor
timestamp: March 12, 2013, 08:26:32 pm
content: http://www.amazon.com/USB-Mass-Storage-Designing-Programming/dp/1931448043You can also find pdf of that book.
USB oscilloscope projects - Page 1
Forum section: electronics / projects

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: August 09, 2018, 02:53:59 am
content: I used the USB project fromwww.waitingforfriday.comas the basis for a USB low frequency oscilloscope.It managed 460,000 samples per second and was good for about 20KHz.My next project was 1,000,000 sampler per second scope but I found the op amps I used struggled with anything over 20KHz.The op amp gain/bandwidth was 3MHz and input bias current was 1pA so it should have been fine.The problem turned out to be a 1 meg input resistor in conjunction with the op amp input capacitance giving a loss of 50% at 20KHz.The input capacitance was 8pf so I put a 10pf in parallel with my 1 meg resistor and this compensated for the losses.
USB over WiFi - Page 1
Forum section: electronics / projects

author: Alex
author_rank: Regular Contributor
timestamp: May 25, 2017, 10:11:45 am
content: Hello, I have a high-level technical question.There is an NI DAQ with USB 2.0 interface, relatively low bandwidth, that I need to talk to over WiFi.I have read that a USB host server is what is needed to effectively do USB over IP (Ethernet). Then, a wireless bridge can communicate with the data acquisition PC.What is your view on this? Is there a better way to go about it?Many thanks,Alex

author: Cliff Matthews
author_rank: Unknown
timestamp: May 27, 2017, 12:28:31 am
content: WiFi is a means of transport like Ethernet. Google "USB over IP" and you'll findstuff like this(and others).

author: Alex
author_rank: Regular Contributor
timestamp: May 27, 2017, 12:48:51 pm
content: Thanks Cliff, I am gravitating towards somethinglike this, a USB device server. I could use the ethernet version with an external bridge or the version with the built-in wifi.Alex

author: Cliff Matthews
author_rank: Unknown
timestamp: May 27, 2017, 07:10:46 pm
content: Yeah, that project seemed to go off the rails by 2012. On the off chance the original SF project went commercial, I saw results (you follow if req'd)here. One thread seemed to discuss other optionshere. Good luck!*Edit the 510 model ($92.00) has someQ&A and some user feedbackon Amazon. (shouldn't be that different with devices than the 520 wireless unit).
Usb PD soldering station - Page 1
Forum section: electronics / projects

author: bryanh2
author_rank: Newbie
timestamp: January 13, 2021, 06:34:25 pm
content: Hi Guys,I've just started designing a soldering station for by Usb PD powered TS80 Soldering Iron.The iron is powered by 12v 2.5a via USB PD. What is the best way to power both the soldering iron and a 12v 0.3a dc fan from the same power source?I would preferably like to have a female usb type c port at the front of the station. Would the diagram attached work or is there a better way to do this?Thanks,Bryan

author: poorchava
author_rank: Super Contributor
timestamp: January 13, 2021, 07:37:44 pm
content: You have a front panel usb 3.0 type A on your picture.You want a host or device connector on the front?I mean u can get it to work either way. It should work as long as ground is the same and USB voltages are what they should (ie 5V on USB type a, not 12)

author: Distinctly Average
author_rank: Contributor
timestamp: January 13, 2021, 07:54:10 pm
content: If you look closely at the picture, the adapter had a USB C port at the bottom as well and it mentions PD. So it should be fine.

author: bryanh2
author_rank: Newbie
timestamp: January 13, 2021, 11:52:32 pm
content: Quote from: poorchava on January 13, 2021, 07:37:44 pmSorry yes its meant to be a female usb c port to deliver the 12v. Thanks

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 14, 2021, 02:35:07 pm
content: Buy a cheap USB-C extension cable (you only need one that extends power and the basic signals, the high speed data is not necessary) and splice the fan into the power and ground wires.

author: tooki
author_rank: Super Contributor
timestamp: January 14, 2021, 02:52:49 pm
content: Or get a power supply with the USB-C PD for the iron plus a regular USB A which you use with a 5V fan instead of 12V.

author: bryanh2
author_rank: Newbie
timestamp: January 14, 2021, 04:15:23 pm
content: Yes I think this way will be easier. Thanks!
USB-PD source module/IC - Page 1
Forum section: electronics / projects

author: mtwieg
author_rank: Frequent Contributor
timestamp: August 24, 2024, 03:12:49 pm
content: For a device I'm developing, one of the requested features is that the device be capable of providing power to charge tablets/smartphones. In particular they want USB-PD, capable of 20W of power. Data transfer is not required (beyond supporting the power negotiation stuff). Device already has a 36V DC supply (could step this down to 12-24V if necessary).I'm not familiar with modern USB specs at all, so I was hoping to find a breakout board/module solution. Not a product in a plastic housing, but a board I can solder onto another PCB assembly. It seems like there are lots of options for triggers on the sink side, but very little on the source side. Closest I can findis this thing, but the fact that Vin has to be wired into screw terminals is a pain.Is there anything else I'm missing? I can't choose anything from Amazon/ebay/aliexpress/etc, needs to be sold through a "trustworthy" distributor (not sure if Mikroe meets that criteria). I'm surprised TI/STM/Cypress don't offer some options here.

author: radiolistener
author_rank: Super Contributor
timestamp: August 24, 2024, 03:21:41 pm
content: This module is pretty good for their price. Supports almost all PD/QC modes up to 100W. Almost no voltage drop even at 100 Watt power consumption.https://www.aliexpress.com/item/1005005281312049.htmlWithout metal shell it will cost about 50 cents less, so I suggest to buy it with metal shell.For 20W you can feed it with 12V 2-3 Amps.Voltage doesn't matter, it supports up to 28V, but in order to get 20W you needs to provide at least 12V and enough current, the rest things will be done with module.Optimal feed voltage to get max efficiency (minimum heating) at 100W output is 22-23 V. So you can feed it with 24V, it will be almost the same good.

author: mtwieg
author_rank: Frequent Contributor
timestamp: August 25, 2024, 01:02:49 pm
content: Quote from: radiolistener on August 24, 2024, 03:21:41 pmThanks... even if this thing is functional, I can't make use of it due to reasons I mentioned in my first post (can't use aliexpress as vendor, and would be very difficult to integrate this thing in the product).If a chip vendor (TI/cypress/STM) made a suitable breakout board for $50 then I would absolutely choose that. That's less than a drop in a bucket compared to the cost of the overall product.
USB-PD Trigger + PPS with potentiometer - Page 1
Forum section: electronics / projects

author: centylab
author_rank: Newbie
timestamp: January 17, 2024, 09:14:37 pm
content: Due to my work with USB PD, it has not been easy to re-program the open-sourcePicoPDboard when I need a different voltage. Most of the USB-PD trigger boards with PPS utilize a button to select between voltages. Some boards also don't save PPS settings so you have to set up again at every bootup. So I have designed this PPS board to change the PPS voltage with just a potentiometer. PPS stands for Programmable Power Supply, it is an add-on to USB-PD 3.0 standard that allows you to request 3.3V to 21V from a charger/power bank, sometimes up to 5A (PD3.1) in the whole range.It is a good enough "portable power supply" if you have a power bank that also supports USB-PD PPS. Imagine I can just show up in class and whip out my adjustable voltage supply. Check out the project atPPSTriggerTheory of operationThe device utilizes the AP33772_CPP library. Using the awesome USB-PD standard, the PPS mode can provide equal or more current than the fixed PDO within its voltage range (3.3V-11V or 3.3V-21V) except for 20V for some chargers. The device will always try to negotiate using the PPS profile first. If the charger is missing PPS capability or the PPS voltage range is under the selected voltage, a fixed PDO will be used.There is no current limit, you can use up to the rated current on the charger. Higher than spec current draw will cause the charger to reset and re-connect after a couple of seconds. This is a standard safety in USB-PD charger.
USB PD when load requires more than 5V/15W at startup - Page 1
Forum section: electronics / projects

author: theoldwizard1
author_rank: Regular Contributor
timestamp: May 30, 2023, 01:07:32 pm
content: I know enough about USB PD 3.X to know that the voltages and currents what can be delivered. I also know, that the default voltage is 5.0V (3.0A?). But what do you do if the device requires more than 15W to boot up and request/negotiate for more power ? Do they make an buck converter IC that can negotiate this (based on a pin) and not supply voltage to the rest of the circuit until the power is delivered.Also, are there any buck converter ICs that can handle a nominal 15V input and produce a 3.3V or 5V output at <500ma WITHOUT an additional drive FET or coil ?

author: ajb
author_rank: Super Contributor
timestamp: May 30, 2023, 02:54:08 pm
content: There are ICs designed to handle USB PD negotiation, some can be configured for operation independent of an MCU or processor, and there's often some sort of 'power good' signal. You could use one of those to negotiate for you, then enable whatever downstream converters/other circuitry you need for the main device to start up. I'm not sure how that would work if the device needs to enumerate after the bootup process, but I imagine there are provisions for that in the USB/PD specs.Quote from: theoldwizard1 on May 30, 2023, 01:07:32 pmWithout an external FET, yes. Without an external coil, no, because the coil is kind of mandatory. There are DC-DC converter modules that have the coil built in, though, including some that look like ICs and can be soldered like ICs, which you can find at your favorite distributor under 'board mount DC-DC converters' or similar.
USB PD/QC Trigger IC - anybody know what these A/Exp modules use? - Page 1
Forum section: electronics / projects

author: sleemanj
author_rank: Super Contributor
timestamp: June 04, 2022, 12:44:11 pm
content: Simple question, these dip-switch-selectable modules you find on Aliexpress etc...ExampleAnybody know what IC they might use?

author: sleemanj
author_rank: Super Contributor
timestamp: June 04, 2022, 01:47:14 pm
content: Answering my own question, I think they areXSP06and I also found another oneFastSOC FS312English Datasheet(from here, I've saved a copy locally if this goes away)I couldn't find either of these at LCSC, indeed only one Taobao seller. The Fastsoc one looks pretty nice actually with really wide voltage tolerance on DP/M and CC1/2 so basically no external protection or regulation required. Thatseller seems to specialise in these USB trigger/decoy/protocol type chipsThere is this similar sort of thing available at LCSCLDR6328but it will just negotiate the highest available I think (with a max of 12v or 9v depending on if you pull pin 2 down or not).Here is anotherIP2721no stock at LCSC but looks like it has been in the past, might be out of production as not mentioned on the manufacturer's site. Has been used in anopen source projectpreviously.

author: hbozyq
author_rank: Contributor
timestamp: September 08, 2022, 04:56:02 am
content: I guess its CH224K.Its used to request fixed voltage(5/9/12/15/20V) from smart phone charger.Supported protocol include PD/QC/BC2.1 etc.

author: thm_w
author_rank: Super Contributor
timestamp: September 08, 2022, 10:12:14 pm
content: If its for hobby use, its often easier and likely even cheaper to just buy these boards and then solder them on to your design.Looks like the CH224K mentioned above is available for ~50c though:https://www.lcsc.com/product-detail/USB-ICs_WCH-Jiangsu-Qin-Heng-CH224K_C970725.htmlOr possibly less from Ali:https://www.aliexpress.com/item/1005004305959345.html

author: sleemanj
author_rank: Super Contributor
timestamp: September 09, 2022, 02:44:53 am
content: FWIW, I used the FS312it does what it says on the tin. Voltage change works on the fly as well.I don't know if the 5.1k resistors are required or are handled internally, but there's space for them on my PCB just in case, my supplies all worked without them.
USB Port Reverse Current - Page 1
Forum section: electronics / projects

author: electosleepy
author_rank: Contributor
timestamp: September 02, 2016, 01:16:58 pm
content: Hi,I'm currently making my own PCB and I want my project to be powered by a 5V header or a USB power supply. If someone was to connect 5V to the header and accidentally plug in the USB cable to the host device while the host was off, how can I prevent current from flowing through the unpowered USB port?

author: tszaboo
author_rank: Super Contributor
timestamp: September 02, 2016, 01:23:17 pm
content: Connect a logic level PFET in series with the USB VBUS, intrinsic diode the obvious way, connect gate to ground.

author: Fungus
author_rank: Super Contributor
timestamp: September 02, 2016, 01:31:27 pm
content: Quote from: electosleepy on September 02, 2016, 01:16:58 pmNormally you'd use one of the incoming voltages to operate a P-channel MOSFET. The MOSFET controls power coming from the other input and switches off when there's there's a voltage on the first input.eg. In the Arduino Uno the USB power is disconnected when 5V is present on the Vin line. The Uno schematic is easy to find...
USB Power Buffer - Page 1
Forum section: electronics / projects

author: kkbb
author_rank: Contributor
timestamp: July 26, 2018, 08:42:28 pm
content: Hello All,A usb-powered device I am designing draws 650 ma for 30 milliseconds, and then settles down to draw less than 500 ma.I understand that most computer USB ports can safety provide 500 ma @ 5V.Without resorting to an external power supply, what are my options for powering this device from a computer's USB port?Some ideas I had was to have a small li-ion battery, supercap, etc. But not sure on how to go about it.Thanks

author: jbb
author_rank: Super Contributor
timestamp: July 27, 2018, 03:26:33 am
content: So, the USB standard is often abused. Many people would just suck down the 650mA anyaway.Options:- just do it and see what happens. It’s probably fine if you’re only making a couple.- require a USB3 port (900mA)- modify design to say within 500 mA (e.g. efficiency improvements, change operation sequence). Can you turn off parts of the circuit during the leak load (e.g. put sensors and processor to sleep)?- add capacitor storage (note, there are rumours that supercaps may leak)- add battery storageI would recommend against batteries for any production devices because they are really hard to ship these days (basically, sea freight only), need chargers, protection etc.

author: RoadRunner
author_rank: Frequent Contributor
timestamp: July 27, 2018, 07:53:08 am
content: i belive 650 mA should be okey for quick time, PTC need some time to blow up and also have trip current higher than hold current,Before USB3.0 when i use to have USB 2.0 Hard Drive they all use to supply a wierd USB cable which connects to two ports and can supply extra power from the two ports. my Hard Drive use to work in most PCs but some time when you have some stupid machine and front panel usb port then you need to connect extra power cable.you can try it in most PCB it will work with just one USB port , if does not user may need to supply extra power.
USB power monitor - Page 1
Forum section: electronics / projects

author: Phaedrus
author_rank: Frequent Contributor
timestamp: January 22, 2014, 05:21:45 pm
content: I'm looking into a simple project to measure voltage and current on USB. Something that would fit between a charger and a tablet, for instance, and report V/A/W to the tablet screen (some software there of course). Just a simple MCU plus a 0.1% shunt resistor and some passives.What's a good MCU with at least two >8-bit ADCs that would be suitable for this? I've been looking at the TI MSP430, but was wondering if there might be better options.

author: kripton2035
author_rank: Super Contributor
timestamp: January 22, 2014, 05:31:32 pm
content: easier and cheaper ... I did not say more precise ...http://dx.com/p/3-3-led-4-digit-red-display-0-10v-0-5a-usb-power-charger-current-voltage-tester-blue-silver-284467#.UuAAUI1KFFU

author: Phaedrus
author_rank: Frequent Contributor
timestamp: January 22, 2014, 05:45:55 pm
content: Looking for a project, not an off the shelf one.

author: kripton2035
author_rank: Super Contributor
timestamp: January 22, 2014, 06:18:19 pm
content: usb can pass 2 amps of current, if you want to measure the milliamp, you need a >11 bits for the adcpart from that, any mcu can do the job.

author: mariush
author_rank: Super Contributor
timestamp: January 22, 2014, 06:38:29 pm
content: Well, go do it then... grab a pic or atmega and a couple of adcs and you can basically do it on a breadboard.Even 16-18 bit i2c ADCs are a few dollars, and those will give you enough precision to measure up to 2-3 amps with no problems at all.

author: MLXXXp
author_rank: Frequent Contributor
timestamp: January 22, 2014, 07:35:40 pm
content: Note that for a mini-USB or micro-USB connection, the extra fifth pin, not present on full size USB, may affect current draw. This pin is sometimes used to indicate that the device is a charger and is able to provide higher current. To do this the pin might be tied to ground, or be on a resistor to +5V or ground, or on a resistor divider between +5V and ground. If you want correct current measurement in this case, you may need to bring this pin through from the charger to the device.Cables with connections to this pin are very rare. For a mini-USB breakout board that I built, I ended up cutting into and stripping away the plastic of a moulded mini-USB connector, to add an extra wire to the fifth pin. I then sealed the connector back up with wire, solder and heat-shrink tubing.Attached are some pictures.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: January 22, 2014, 07:41:44 pm
content: Thanks,I'd prefer a single chip solution, but I'll throw a cheap 12-bit ADC in there if I need it. For now I'm looking at the ATmega16U4. It does everything I need, except that it requires a <3.6V supply, which isn't ideal for 5V USB. And throwing an inefficient in LDO in there might affect the voltage output of the charger...

author: notsob
author_rank: Frequent Contributor
timestamp: January 22, 2014, 08:48:20 pm
content: There's this one that dave showed on a mailbaghttp://www.jmedved.com/usbamps/
USB Power supply, 5V or 5.12V ? - Page 1
Forum section: electronics / projects

author: smbaker
author_rank: Regular Contributor
timestamp: December 12, 2018, 12:04:25 am
content: I have a usb power supply project that I'm planning on building. I can trim it out to supply exactly 5V, or I can go a little bit higher, for example 5.12V.Knowing that there's usually a healthy cable voltage drop in even most decent USB cables, let alone your typical crappy cable, I'm thinking that 5.12V seems like the reasonable choice. I also see that there's lots of 5.1V power supplies on the market, and that they're often recommened for, for example, rasbperry pi.This power supply will be used for powering projects, as well as charging iphones and similar devices.Thoughts on 5V vs 5.1V?Scott

author: james_s
author_rank: Super Contributor
timestamp: December 12, 2018, 12:39:52 am
content: You're splitting hairs here. 5.12V is well within the tolerance for USB and won't hurt anything. Given cables will all have some drop, it's probably not a bad idea to err a little on the high side.

author: DaJMasta
author_rank: Super Contributor
timestamp: December 12, 2018, 01:59:10 am
content: 5.1V or so is probably fine, for reasons mentioned. That said, if you want to charge phones and things using higher than normal USB currents, you need the appropriate IC to negotiate that protocol, and often have to supply higher voltages.

author: bson
author_rank: Unknown
timestamp: December 12, 2018, 06:18:02 am
content: Aim a little high; it's common for USB devices to have a Schottky diode on VBUS.

author: TERRA Operative
author_rank: Super Contributor
timestamp: December 12, 2018, 01:26:19 pm
content: The USB spec allows up to 5.25V (5V +/-5%), so 5.12V will be perfectly fine (and help allow for voltage losses through cables and connectors and reverse polarity protection diodes etc).https://en.wikipedia.org/wiki/USBSee the right hand sidebar for details.
USB Powered Arduino and Floating Power Supply - Page 1
Forum section: electronics / projects

author: Charles Creations
author_rank: Contributor
timestamp: December 18, 2014, 12:18:54 am
content: Hi,I am working with an arduino uno that I have hooked up to an analog amplifier that I feed with a 15V supply from by bench supply. I attach the ground lead of the bench supply to the ground of the USB on the arduino uno, and the 15V positive lead to the amplifier voltage rail. The arduino runs perfectly while the 15V supply is off, but when I turn the 15V supply on, the arduino slowly browns out over about 3 seconds (LED grow dimmer, and it reenters setup in the program). It goes into an infinite loop through its setup, so I see the serial terminal sending "Starting up" repeatedly.Anyone have any advice on using a bench supply to supplement a USB supply when you must keep USB intact for serial com?Oddly enough, if I am measuring the voltage of the USB 5V rail with my multimeter or oscilloscope, then the brownout does not occur... I cannot explain it. Strangely reminds me of Heisenberg uncertainty principle because every attempt to measure it causes something else.Thanks,Charlie

author: Fraggie
author_rank: Newbie
timestamp: December 22, 2014, 12:25:42 am
content: Are both power supplies switching power supplies ?Had a weird thing myself , powering a odroid board from a switching laptop supply , no probblems, using a dc-dc converter from 24 to 12v , and the powerled on the odroid starts lighting up and dimming in sequence.. weird. (dc-dc rated 5A)I power a arduino from the pc(usb) and a steppermotor from a 12v laptop psu.. no problems.You do need to tie both the negative wires together from the arduino and the other board.. (even is one is 5v and the other 12v)That might be it.

author: alimirjamali
author_rank: Regular Contributor
timestamp: December 22, 2014, 12:40:01 am
content: Quote from: Charles Creations on December 18, 2014, 12:18:54 amConnect Ground of your bench supply to one of two ground pins and the +15V toVIN. I emphasize again:VIN. There is a NCP1117 regulator and a bunch of diodes and MOSFETs that will take care of both bench supply and USB power.See picture below (1st and 2nd PINs from right; Power header):