stf203 Semtech Corporation, stf203 Datasheet - Page 4

• Manufacturer Part Number: stf203
• Description: Stf203 Usb Upstream Port Filter & Tvs For Emi Filtering And Esd Protection
• Manufacturer: Semtech Corporation

1 . 1 .
1 . 1 . Full-Speed Devices: For full-speed devices the
2 . 2 .
2 . 2 . Low-Speed Devices: : : : : For low speed devices the
Device Connection
The STF203 is designed to provide termination, EMI
filtering and ESD protection for one USB port. The
device is connected as follows:
1 .
2 .
USB Port Design Considerations
The Universal Serial Bus (USB) specification requires
termination and filtering components for proper opera-
tion. In addition, an open USB socket is vulnerable to
hazardous ESD discharges in excess of 15kV. These
discharges can occur on the data lines or the voltage
bus. The STF203 is an easily implemented solution
that is designed to meet the termination and EMI filter
requirements of the USB specification revision 1.1. It
also provides ESD protection to IEC 61000-4-2,
level 4.
USB line termination is achieved with series resistors
on both the D+ and D- lines. These resistors preserve
signal integrity by matching the cable impedance to
that of the differential driver. A 1.5k
is used to identify an upstream port on either the D+
(full speed devices) or the D- (low speed devices) data
line. Capacitors are used for EMI suppression. TVS
diodes provide ESD protection of both (D+ and D-)
data lines and the voltage bus (V
integrates all of these components in a small SC-70
package. This integrated solution simplifies design and
requires minimal board space.
PROTECTION PRODUCTS
Applications Information
2006 Semtech Corp.
pull-up resistor is connected to the D+ line. Route
the D+ line from the connector to pin 1 of the
STF203. Pin 6 is connected to the D+ line of the
IC. Route the D- line from the connector to pin 3.
Pin 4 is connected to the D- line of the IC. Pin 5 is
connected to the voltage supply line (V
connected to ground. Note that the input and
output connections may be reversed if necessary
(See Figure 3).
pull-up resistor is connected to the D- line. Route
the D- line from the connector to pin 1 of the
STF203. Pin 6 is connected to the D- line of the IC.
Route the D+ line from the connector to pin 3. Pin
4 is connected to the D+ line of the IC. Pin 5 is
connected to the voltage supply line (V
connected to ground. Note that the input and
output connections may be reversed if necessary
(See Figure 4).
BUS
). The STF203
pull-up resistor
BUS
BUS
). Pin 2 is
). Pin 2 is
4
STF203-15 THRU STF203-33
From Connector
From Connector
Figure 1 - Preferred Connection Diagram
Figure 2 - Preferred Connection Diagram
Figure 3 - Alternate Connection Diagram
Figure 4 - Alternate Connection Diagram
(Low Speed Devices)
(Low Speed Devices)
(Full Speed Devices)
(Full Speed Devices)
1
2
3
1
2
3
STF203
STF203
1
2
3
1
2
3
STF203
STF203
6
5
4
6
5
4
6
5
4
6
5
4
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From Connector
From Connector