PRTR5V0U2F_PRTR5V0U2K_2 © NXP B.V. 2009. All rights reserved.
Product data sheet Rev. 02 — 19 February 2009 7 of 12
NXP Semiconductors
PRTR5V0U2F; PRTR5V0U2K
Ultra low capacitance double rail-to-rail ESD protection
7. Application information
Handling data rates up to 480 Mbit/s, USB 2.0 interfaces require ESD protection devices
with an extremely low line capacitance in order to avoid signal distortion.
With a capacitance of only 1 pF, the PRTR5V0U2F and the PRTR5V0U2K offer
IEC 61000-4-2, level 4 compliant ESD protection.
PRTR5V0U2F and PRTR5V0U2K integrate two pairs of ultra low capacitance rail-to-rail
ESD protection channels and one additional ESD protection diode each.
The additional ESD protection diode connected between ground and V
CC
prevents
charging of the supply.
Circuit board layout and protection device placement
Circuit board layout is critical for the suppression of ESD, Electrical Fast Transient (EFT)
and surge transients. The following guidelines are recommended:
1. Place the PRTR5V0U2F and the PRTR5V0U2K as close to the input terminal or
connector as possible.
2. The path length between the PRTR5V0U2F or the PRTR5V0U2K and the protected
line should be minimized.
3. Keep parallel signal paths to a minimum.
4. Avoid running protected conductors in parallel with unprotected conductors.
5. Minimize all Printed-Circuit Board (PCB) conductive loops including power and
ground loops.
6. Minimize the length of the transient return path to ground.
7. Avoid using shared transient return paths to a common ground point.
8. Ground planes should be used whenever possible. For multilayer PCBs, use ground
vias.
Fig 5. Application diagram: USB 2.0
006aaa485
D+
D−
D+
D−
GND
USB controller
common mode
choke
protected IC/device
V
BUS
V
BUS
