Introduction
I love the Microsoft Surface product line – so when I hear about a new docking accessory, I have to buy it. The SPD82 by X-SPD is an innovative product concept. In a tiny form factor, it allows charging your Surface through the Microsoft proprietary 40-pin connector via USB-C power delivery while also providing a USB 5Gb/s data port. This is especially helpful if you have an older Surface Book with a broken keyboard base.
There are two models: a Pro version [alternate link] [ebay affiliate link] with red PCB enables data (not video) on both the USB-C and USB 3.x ports, and a non-pro version [alternate link] [ebay affiliate link] with black PCB that enables data on the USB 3.x port but only power on the USB-C port. I tested the non-pro version.
Physical Characteristics
The magnets in the SPD82 are about half the strength of the official Surface connector so it doesn’t get sucked into the port as firmly but they are strong enough to keep it connected. Unlike the zero-insertion force like the original Surface connector, the SPD82 requires a little effort to insert. This is due to the sharp PCB edges. Initially, I was concerned that the sharp edges could wear the pins down or snag and bend a pin, but after using it, I think this is unlikely.
Analysis & Conclusion
Overall, I love the concept. The form factor is perfect and it has a simple feature set of enabling USB-C PD charging at up to 45W and delivering USB 3.x 5Gb/s. Having the PCB edge chamfered at 20° with a depth of 0.5mm would allow for easier ingress to the Surface receptacle. A nice-to-have feature addition would be a small li-ion battery or super capacitor so that the USB port could be used without a power supply for a short time. Even more helpful would be to breakout DisplayPort alt-mode on the USB-C port (other vendors have successfully reverse-engineered the specific resistor values to turn on the DP pins) but this would add considerable complexity & cost to the SPD82.
Similar to many dongle style Surface Connect -> USB-C power adapters, the SPD82 doesn’t make use of the detection pins to switch power on after a device is connected. The presence of +15V on the pins at all times presents a risk of short circuits and arcs which could damage the SPD82, the USB-C power supply, or the Surface.
Given this risk, I cannot recommend the SPD82 for regular use. Once this issue is addressed, I would probably recommend it. To mitigate the risks, don’t hot plug the SPD82. Instead, always start by unplugging the USB-C power supply from AC/Mains before connecting or disconnecting anything else. If you adhere to these guidelines, I think it is probably OK to use.
To Connect:
- Disconnect USB-C charger from AC/mains
- Connect USB 3.x device to SPD82
- Connect USB-C charger to SPD82
- Connect SPD82 to Surface
- Plug USB-C charger into A/C mains
To Disconnect:
- Disconnect USB-C charger from AC/mains
- Disconnect SPD82 from Surface
- Disconnect USB devices from SPD82