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CableDeconn A0206-Z USB-C Gen2 Bi-directional Switch with PD teardown

Writer: goldenstateservicesj
goldenstateservicesj
Jul 5, 2021
3 min read

[Special thanks to /u/hubsdocks for providing the two PCB photos]

[Updated April 2023 with more alternate brands]

Overview

This CableDeconn USB-C Gen2 capable bi-directional switch allows sharing a USB-C monitor, dock, or hub between two PCs with full video (4K60 or 8K30), data (10Gb/s), and power delivery (PD100) switching support. Or it allows a single PC to switch between two high bandwidth/high-power USB-C devices. The device has two USB-C receptacles and a soldered ~0.8m long USB-C cable. Curiously, the unit needs 5VDC supplied by a separate microUSB receptacle. (Why not USB-C?) Other than that, it has a selection switch and 2 LEDs indicating which port is active. As of 2021/07/01 this is the only product in the ~$50-60 USD price class that provides this functionality. Below I’ll dive into the unboxing, physical characteristics, and PCB analysis.

Unboxing & Physical Characteristics

Simple and effective: bag, warranty card, user manual, switch, and microUSB power cable.
The switch with integrated USB-C cable weighs ~85g.
The microUSB power cable weighs ~23g.
The switch is 52mm x 70mm x 13mm
~0.8m integrated USB-C cable
The cable is 5mm thick.

PCB Analysis

The PCB appears to be a 3 or 4 layer design. The top and bottom layers are mostly ground planes and the middle layer is a positive power plane separated into a +3.3V segment and a USB-C power delivery segment (5-20V).

Top PCB photo provided by /u/hubsanddocks
Bottom PCB photo provided by /u/hubsanddocks

Key components on top of PCB from top left (clockwise):

  • •(U7) Nanjing Qinheng Micro (WHC) CH552G microcontroller in a SOIC-16 package (USB-C master/slave detection, USB 2.0, 16KB of built-in flash etc). Close by is an unpopulated 3-pin header labelled RX/TX/GND probably for debugging or programming the MCU flash memory.

  • •(U6, U9, U10, U11, U13) 5x SOP-10 chips labeled with “4227”, “102TC”, and a large “B” logo. Possibly low-speed differential pair switches intended for the USB 2.0, CC1/CC2, and SBU1/SBU2 pins. Presumably, a sixth chip can be added (U12) to support an additional differential pair. For some reason, the capacitor C18 is populated even without U12.

  • •(U3) Unknown TQFN-42 IC probably a PCIe switch by Maxim-Integrated or Diodes-Inc with the markings lasered off to inhibit reverse-engineering efforts.

  • •(U8) SOP-5 IC marked with “AS1108”. This IC appears to regulate 5VDC from the MicroUSB receptacle down to 3.3VDC and delivers it to the middle layer of the board so other ICs can pick it up. Surrounding this are various power filtering components.

  • •(Q1, Q2) SOP-8 with markings “4953C”, “435M”, and “026665” with a logo that looks like a stylized M resembling a waveform. These are probably dual P-channel mosfets handling power delivery to the USB-C receptacles

  • •(Q3, Q4) mosfet labeled “702K”

  • •(Q4, Q5) mosfet labeled “AtsHB”

  • The two USB-C receptacles are labelled U1 and U4 which implies there is some sort of IC under the metal shield. If present, it would either be a signal re-driver/re-timer or ESD protection. Or the PCB layout software just didn’t have these components in the correct “J” category like the microUSB connector (J1)

The bottom of the PCB shows another ground plane, hand soldering of the remaining wires, and the through-hole components including the two LEDs and a single momentary microswitch. A multitude a vias connect the front ground plane to the rear and there are a vias to route differential pair signals between the main switch IC and the USB-C receptacles. There are also rectangular solder pads under the main high speed switch chip and the voltage regulator and inductor (L1) for the microUSB port. These solder pads could be used to attach heatsinks, but adhering thermal pads to transfer heat to the chassis works too.

Final thoughts

Similar products with DisplayPort or HDMI 2.1 receptacles are available. With the viability of such devices at the $30-100 USD price point, I’m hoping to see reasonably priced and full-featured USB-C / USB4 Docks with built-in KVM functionality come to market next year.

There are three distinct designs of these switches sold under a few dozen brand names. the insides are very similar

  • EleCable / Vbestlife / BeWinner / Anndue / Fupei / Ashata Sxhlseller / Pusokei / Zunate

    • powered by USB-C cable

  • CableDeconn / MLeeda / Yiwentec / Chenlenic / CableCC / ConnBull / NFHK / Xiwai

    • powered by microUSB cable

  • KCeve / Aoocoo

    • powered by microUSB cable

    • has buttoin on main chassis and secondary remote button that plugs in via microUSB

$50-$150 USB-C KVM switches

Further reading

 
 
 

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