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STF202-22_04 Datasheet, PDF (1/7 Pages) Semtech Corporation – USB Upstream Port Filter and TVS | |||
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STF202-22 and STF202-30
USB Upstream Port Filter and TVS
For EMI Filtering and ESD Protection
PROTECTION PRODUCTS
Description
The STF202 is a combination EMI filter and line termi-
nation device with integrated TVS diodes for use on
upstream USB ports. It is constructed using a propri-
etary 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 STF202 is
an easily implemented solution for meeting the require-
ments of revision 1.1 of the Universal Serial Bus
specification.
USB line termination is achieved with series 22⦠or
30⦠resistors on both the D+ and D- USB lines. These
resistors preserve signal integrity by matching the cable
impedance to that of the differential driver. The 1.5kâ¦
pull-up resistor completes the termination circuit on
each line. This resistor is required by the USB specifi-
cation 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 used to bypass
high frequency energy to ground and for edge rate
control of the USB signals. Finally, the STF202 con-
tains TVS diodes for ESD protection of both
(D+ and D-) data lines and the voltage bus (VBUS). The
TVS diodes provide effective suppression of ESD
voltages in excess of ±15kV (air discharge) and ±8kV
(contact discharge) per IEC 61000-4-2, level 4.
The small size and integrated feature of the STF202
minimizes required board space and increases system
reliability. The STF202 is suitable for use in USB hubs,
computers, peripherals, and portable devices.
Features
 Bidirectional EMI/RFI filtering and line termination
with integrated ESD protection
 ESD protection for USB power (V ) and data lines
BUS
(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 two USB data lines
 Different series resistors for impedance matching
 Low TVS operating voltage (5.25V)
 Low leakage current
 Low capacitance
 Solid-state technology
Mechanical Characteristics
 EIAJ SOT23 6L package
 Molding compound flammability rating: UL 94V-0
 Marking : Marking Code
 Packaging : Tape and Reel per EIA 481
Applications
 USB Hubs
 Portable electronics
 Cellular Handsets
 Modems
 Peripherals
 Servers, Desktop, Notebook, and Handheld
Computers
Circuit Diagram
Schematic and PIN Configuration
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Revision 08/11/04
S0T23-6L (Top View)
1
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