IEI Integration ICE-DB-9S - Manual (Page 70)

Page 57
ICE Module
4.5.3 ESD/EMI
To improve the EMI behavior of the USB interface, a design should include common
mode chokes, which have to be placed as close as possible to the USB connector
signal pins. Common mode chokes can provide required noise attenuation but they
also distort the signal quality of full-speed and high-speed signaling. Therefore,
common mode chokes should be chosen carefully to meet the requirements of the
EMI noise filtering while retaining the integrity of the USB signals on the carrier board
design.
To protect the USB host interface of the module from over-voltage caused by
electrostatic discharge (ESD) and electrical fast transients (EFT), low capacitance
steering diodes and transient voltage suppression diodes have to be implemented on
the carrier board design.
IO_GND
USB0-_R USB1-_R
D10
PACDN006
1
2
3 4
5
6
USB1+_R USB0+_R
+V5_USB01
Figure 4-21: RailClamp SRV05-4 Low Capacitance TVS Diode Array for ESD
USB1-_R
USB1+_R
USB1- 3
USB1+ 3
L17
COMCHOKE_8_USB
1
4
2
3
Figure 4-22: 90 ohm Common Mode Choke at 100MHz for EMI