As I'm not really happy with the response to my previous query:
So I thought I would investigate the issue further.
I've configured a USB-C breakout board with a 3.3ohm load (1.5A at 5v) and two ~5Kohm configuration channel pull down resistors.
On connecting this to either NUC thunderbolt port (either directly or via my cable) all I see is a 10ms attempt to raise the voltage to 4v every second or so. It looks like the NUC is preventing the power delivery.
On connecting same 'device' to my ASUS PN-1 thunderbolt ports I get a steady 4.8v
According to the Specifications the thunderbolt ports should be able to provide 3amps. They are failing with my modest requirement of 1.5A.
SSU output log attached.
Link Copied
Hello comsci,
If you refer to our documentation, see TPS, page #15 the Thunderbolt ports should provide 15W and 7.5W
https://www.intel.com/content/dam/support/us/en/documents/intel-nuc/NUC11TN_TechProdSpec.pdf
From your previous report, are you connecting this camera: https://docs.microsoft.com/en-gb/azure/Kinect-dk/hardware-specification#power-device ,and are you using the following cables: https://www.ebuyer.com/822466-startech-com-usb-c-to-usb-c-cable-m-m-1-m-usb315cc1m?
What happens when the camera is connected?
Regards,
Ronny G
Hi Ronny,
Yes so 7.5W at 5v equates to 1.5amps which is what teh cameras claim to draw at what my pseudo device attempts to draw.
Upping the resistor to 6ohms (0.833A draw) and it works OK (I get 5V accross the resistor), so I think whatever protection circuitry is employed is shutting the output off prematurely when the load is 3.3ohms.
When I plug a camera in, I get a flashing amber LED on the camera that indicates insufficient power. On hooking my scope up to the Vcc line at the NUC end of the cable I get:
It looks like 5V is supplied, but 20ms after plugging in the camera the voltage drops to about 4v so presumably the camera disables itself and signals insufficient power.
Best regards,
David
