Schematic review - Page 1
Forum section: electronics / beginners

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 07:36:55 am
content: would this be correct for a C-6pin male port for a dock that i can then copy paste 10 times? trying to make a 10 Plug dock

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 01:35:53 pm
content: You can't simply supply 5V on VBUS without role negotiation. 5.1 kOhm resistors indicated the device port, which should not supply any voltage. Hosts use pull-up resistors and resulting divider indicates what is plugged in into the connector,

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 01:47:59 pm
content: so i do this instead then correct?

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 01:56:19 pm
content: No, on the host side you need to do active sensing and only enable VBUS if a device is detected (pull-downs on either of CCx). Connecting two hosts together is a valid configuration in USB-C, neither of the hosts should supply the power in that case.

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 02:00:07 pm
content: yeah that's what im trying to do this is the host im trying to make a 10 port usb-C Male plug charge board basically, i put the resistors from the CC pins to the 5V rail now on the plugs is that the correct configuration in that way then?

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 02:07:04 pm
content: There is no sensing. See what happens if you take two of those docks and plug into arch other's ports. You will get 5V from both boards connected together.You need to have comparators from CCx pins and a logic that controls the EN pin based in the sensed voltage.Otherwise this is equivalent to just connecting VBUS to 5 V, TPS2552 is not doing anything here.

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 02:12:04 pm
content: I'm so confused so I'm just trying to make a dumb board with 10 ports that supply power when something is plugged in (in my case an nRF 52840 Nice!Nano development board ) so what else do i need to make it work then? The 10 port board is all powered by a barrel jack

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 02:30:48 pm
content: According to what I've read i only need sensing if i want to comply with strict safety stuff but I'm just trying to make a dumb board that has max current in each port of 0.5A ( as that's all i need ) and charges a little nRF device

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 03:03:00 pm
content: For a dumb board you don't need anything, just connect 5V to VBUS pins. TPS2552 in this configuration is basically equivalent to a wire, it does nothing.This will not be compliant with USB spec, so make sure to not plug anything into those ports other than charged devices.

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 03:10:25 pm
content: shouldn't the TPS2552 limit the current to 0.5A in this config?

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 03:22:34 pm
content: Sure, if you really need the current limit, then keep it. But for a simple power station it does not seem necessary.

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 04:01:37 pm
content: ok went and did this since it seems better in the long run what you said to be honestso is this then correct for being able to negotiate with the device for a max output of what the IC is rated for so 1.5A ( since i don't want to have to make the entire thing too bulky if it's able to draw a lot of power )

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 04:08:34 pm
content: I have not worked with those specific ICs, but on a quick look this seems fine.

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 04:21:42 pm
content: ok so i added the VBUS_DISCH stuff now so i think this is correct and even to spec for USB-C? max output of 1.5A, 5V?now i just copy paste this 10 times and wire it together... which will take time and be a pain,i also need to switch my input fuse now and my bulk cap to a higher spec as at Max this thing should then be able to draw 15A i think?soo thicker traces and all that too

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 04:29:14 pm
content: Your discharge configuration does not match the datasheet. The transistor type is incorrect and discharge resistor must have a low value (820 Ohm in the reference design). With 700 kOhm discharge will take a very long time.

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 04:37:29 pm
content: soooooo this is then correct, right?

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 04:40:02 pm
content: You again have 820 kOhm instead of 820 Ohm. Just copy the reference schematic.

author: Yunadex
author_rank: Contributor
timestamp: June 02, 2025, 04:44:30 pm
content: ok fixed that everything else was correct right?

author: ataradov
author_rank: Super Contributor
timestamp: June 02, 2025, 04:48:17 pm
content: It looks fine. I personally would prototype this before ordering big boards.

author: temperance
author_rank: Super Contributor
timestamp: June 02, 2025, 05:43:39 pm
content: Same topic here:https://www.eevblog.com/forum/beginners/id-love-a-little-grilling-tell-me-everythng-i-did-wrong-please/msg5934884/?topicseen#msg5934884