72
Figure 19
: USB 2.0 Good Downstream Power Connection
2.7.2.3 USB 2.0 Common Mode Chokes
Testing has shown that common mode chokes can provide required noise attenuation. A design should
include a common mode choke footprint to provide a stuffing option in the event the choke is needed to
pass EMI testing. Below figure shows the schematic of a typical common mode choke and ESD
suppression components. Place the choke as close as possible to the USB connector signal pins.
Figure 20
: USB 2.0 A Common Mode Choke