License: CERN-OHL-S v2
DPSwitch is a simple KVM-style device that allows you to switch Display Port & USB2.0 between two source devices (eg. a Laptop and a PC):
It is built around the HD3SS215 DP/HDMI mux chip by Texas Instruments, and has a simple flip-flop circuit and two physical buttons to select the input to route to the output. No firmware is required!
I abuse the HD3SS215's HDMI DDC lines to switch USB2.0 signals, and while the datasheet doesn't specify a maximum bandwidth for these lines, it appears to work fine. This avoids the need for a separate mux to switch USB.
| Qty | Description | Part Number |
|---|---|---|
| 1 | DP/HDMI 2:1 Mux 6Gbps | HD3SS215RTQT |
| 1 | Dual NAND Gate | 74LVC2G00DC,125 |
| 1 | 0603 Side look LED (Blue) | KPA-1606QBC-D |
| 2 | 0603 SMD LED (Green) | |
| 2 | Button (SMD) | PTS645* |
| 1 | USB Type-A Conn (TH) | SS-52100-001 |
| 2 | Micro USB Conn (SMD) | 609-5379-2-ND |
| 2 | Diode | BAT54GWJ |
| 3 | DisplayPort Conn | MOLEX 47272-0001 |
Plus various 0603 resistors & capacitors. See schematic.
Since DP operates in the GHz range, the PCB must be impedance controlled, and utilizes a 4 layer stackup. I used JLCPCB's 4-layer 'JLC7628' PCB with a dielectric constant of 4.6, and a black solder mask.