USB Upstream Port Filter and TVS
For EMI Filtering and ESD Protection
PROTECTION PRODUCTS
Description
The STF203 is a combination EMI filter and line
termination device with integrated TVS diodes for use
on upstream USB ports. It is constructed using a
proprietary technology that allows passive components
and TVS diodes to be integrated in the same package.
Each device will provide termination, filtering, and ESD
protection for one upstream USB port. The STF203 is
an easily implemented solution for meeting the
requirements of revision 1.1 of the Universal Serial Bus
specification.
Line termination is achieved with series resistors on
both the D+ and D- USB lines. The value of series
resistance added to the output impedance of the USB
driver must be as close to possible to the 45
Ω
characteristic impedance of the cable (90
Ω
balanced)
to minimize transmission line reflections. They are
available with resistor values of 15
Ω
(STF203-15),
22
Ω
(STF203-22), and 33
Ω
(STF203-33). The 1.5k
Ω
pull-up resistor is required by the USB specification to
identify the equipment as either a full-speed
(connected to D+ line) or low-speed (connected to D-
line) device. The 47pF capacitors are required to
bypass high frequency energy to ground and to control
the edge rate of the USB signals. The TVS diodes
provide ESD protection of both (D+ and D-) data lines
and the voltage bus (V
BUS
). The TVS diodes on the
input/output pins provide suppression of ESD voltages
in excess of ±15kV (air discharge) and ±8kV (contact
discharge) per IEC 61000-4-2, level 4. The TVS diode
on the V
BUS
pin will suppress ESD discharges in excess
of 25kV per IEC 61000-4-2.
STF203-15 THRU STF203-33
Features
Bidirectional EMI/RFI filtering and line termination
with integrated ESD protection
ESD protection for USB power (V
BUS
) and data lines
(D+ and D-) to
IEC 61000-4-2 (ESD) ±15kV (air), ±8kV (contact)
IEC 61000-4-4 (EFT) 40A (5/50ns)
Filtering and termination for one USB port
Series resistors: 15Ω, 22Ω, and 33Ω
Low TVS operating voltage (5.25V)
Low leakage current
Small SC70-6L package
Solid-state technology
Mechanical Characteristics
EIAJ SC70-6L package
RoHS/WEEE Compliant
Molding compound flammability rating: UL 94V-0
Marking : Marking Code
Packaging : Tape and Reel per EIA 481
Applications
USB Ports
Cellular Handsets
PDAs
Pagers
Digital Cameras
PC Peripherals
MP3 Players
Circuit Diagram
6
.
Schematic and PIN Configuration
1
D In/Out
D In/Out
2
5
4
3
D In/Out
D In/Out
SC70-6L (Top View)
Revision 03/22/2006
1
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