USBUFXXW6 Datasheet, PDF (1/9 Pages) STMicroelectronics – EMI FILTER AND LINE TERMINATION FOR USB UPSTREAM PORTS

®
A.S.D.™
USBUFxxW6
EMI FILTER AND LINE TERMINATION
FOR USB UPSTREAM PORTS
APPLICATIONS
EMI Filter and line termination for USB upstream
ports on:
- USB Hubs
- PC peripherals
FEATURES
s Monolithic device with recommended line termi-
nation for USB upstream ports
s Integrated Rt series termination and Ct bypass-
ing capacitors.
s Integrated ESD protection
s Small package size
DESCRIPTION
The USB specification requires upstream ports
to be terminated with pull-up resistors from the
D+ and D- lines to Vbus. On the
implementation of USB systems, the radiated
and conducted EMI should be kept within the
required levels as stated by the FCC
regulations. In addition to the requirements of
termination and EMC compatibility, the
computing devices are required to be tested for
ESD susceptibility.
The USBUFxxW6 provides the recommended line
termination while implementing a low pass filter to
limit EMI levels and providing ESD protection
which exceeds IEC61000-4-2 level 4 standard.
The device is packaged in a SOT323-6L which is
the smallest available lead frame package (50%
smaller than the standard SOT23).
BENEFITS
s EMI / RFI noise suppression
s Required line termination for USB upstream
ports
s ESD protection exceeding IEC61000-4-2 level 4
s High flexibility in the design of high density
boards
s Tailored to meet USB 1.1 standard
TM: ASD and TRANSIL are a trademarks of STMicroelectronics.
March 2002 - Ed: 3A
SOT323-6L
FUNCTIONAL DIAGRAM
3.3 V
Rt
Rp
D1
Ct
Grd
Rt
D2
Ct
D4
3.3 V
D3
CODE 01
CODE 02
Tolerance
Rt
33Ω
22Ω
±10%
Rp
1.5kΩ
1.5kΩ
±10%
Ct
47pF
47pF
±20%
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