4.1.1.3 Tips to Connect JTAG USB Cable

High-voltage boards can generate high EMI due to switching action. Even though the JTAG is isolated, some coupling can still occur due to radiated EMI. This coupling can result in a loss of JTAG frequently. To avoid this from happening, perform the following steps:

1. Wind the USB cable around a ferrite bead as shown in Figure 17.
Figure 17. USB Cable Around Ferrite Bead
2. Make sure the USB cable does not cross directly over the high-voltage section. This setup can be ensured on this design by the following connection of the USB cable.
Figure 18. USB Connection on Board