Upstream USB Port Terminator
PACUSB-U1/U2/U3
©2010 SCILLC. All rights reserved. Publication Order Number:
June 2010 – Rev. 2 PACUSB-U1/U2/U3/D
Features
• One upstream USB port terminator, EMI filter and
transient overvoltage protector in a single
surface-mount package
• Compact SC70 or SOT23 package saves board
space and lowers manufacturing costs compared
to discrete solutions
• ESD protection to ±30kV contact discharge per
MIL-STD-883D, method 3015
• ESD protection to ±15kV contact discharge per
IEC 61000-4-2 international standard
• Lead-free version available
Applications
• ESD protection and termination of USB port
• All USB peripherals (PC printers, scanners,
zip drives, etc.)
• PDAs / handheld PCs
• Digital cameras
• Wireless Handets
• MP3 Players
• Cable Modems
Product Description
The PACUSB-U1, PACUSB-U2, and PACUSB-U3
are single-channel USB upstream-port termination
networks.
The PACUSB-U1/U2/U3 integrate EMI/RFI filter
components R1 and C1, as recommended by the
USB specification. Because these are upstream USB
devices, they are terminated with a single 1.5kW pull-
up resistor to V
3.3
(R2).
There are three options for the value of the series
resistor R1:
• For PACUSB-U1, R1=15Ω
• For PACUSB-U2, R1=33Ω
• For PACUSB-U3, R1=22Ω
This series resistance plus the USB driver output
resistance must be close to the USB cable’s
characteristic impedance of 45Ω (90Ω balanced) to
minimize transmission line reflections.
In addition, these parts provide a very high level of
protection for sensitive electronic components that
may be subjected to electrostatic discharge (ESD).
The input and output pins are designed and
characterized to dissipate ESD strikes of ±15kV
safely, a level well beyond the maximum
requirements of the IEC 61000-4-2 international
standard.
Using the MIL-STD-883D (Method 3015)
specification for Human Body Model (HBM) ESD, all
pins are protected for contact discharges to greater
than ±30kV.
The PACUSB-U1/U2/U3 is housed in either a 6-pin
SC70 or 6-pin SOT23 package and is available with
optional lead-free finishing.
