SEMTECH STF202

STF202-22 and STF202-30
USB Upstream Port Filter and TVS
For EMI Filtering and ESD Protection
PROTECTION PRODUCTS
Description
Features
The STF202 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 STF202 is
an easily implemented solution for meeting the requirements of revision 1.1 of the Universal Serial Bus
specification.
USB line termination is achieved with series 22Ω or
30Ω 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 1.5kΩ
pull-up resistor completes the termination circuit on
each line. This 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 Dline) 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 contains 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.
‹ Bidirectional EMI/RFI filtering and line termination
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with integrated ESD protection
ESD protection for USB power (VBUS) 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 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
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EIAJ SOT23 6L package
Molding compound flammability rating: UL 94V-0
Marking : Marking Code
Packaging : Tape and Reel per EIA 481
Applications
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Circuit Diagram
USB Hubs
Portable electronics
Cellular Handsets
Modems
Peripherals
Servers, Desktop, Notebook, and Handheld
Computers
Schematic and PIN Configuration
.
S0T23-6L (Top View)
Revision 08/11/04
1
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STF202-22 and STF202-30
PROTECTION PRODUCTS
Absolute Maximum Rating
Rating
Symbol
Value
Units
Steady-State Power
Pp k
100
mW
ESD Air Discharge per IEC 61000-4-2
ESD Contact Discharge per IEC 61000-4-2
VESD
16
10
kV
Lead Soldering Temperature
TL
260 (10 sec.)
°C
Operating Temperature
TJ
-40 to +125
°C
TSTG
-55 to +150
°C
Storage Temperature
Electrical Characteristics
STF202-xx
Parameter
Symbol
Conditions
Minimum
Typical
Maximum
Units
5.25
V
T VS Reverse Stand-Off Voltage
VRWM
T VS Reverse Breakdown Voltage
V BR
It = 1mA
T VS Reverse Leakage Current
IR
VRWM = 5.25V, T=25°C
Between VBUS pin and
Ground
5
µA
T VS Reverse Leakage Current
IR
VRWM = 3.3V, T=25°C
Between any data
(D+, D-) pin and Ground.
1
µA
T VS Junction Capacitance
Cj
Between I/O pins and
Ground, each device
VR = 0V, f = 1MHz
Series Resistance (STF202-22)
RS
Each Line
20
22
24
Ω
Series Resistance (STF202-30)
RS
Each Line
27
30
33
Ω
Pull Up Resistance
RUP
Each Line
1.35
1.5
1.65
kΩ
C
Each Line
47
pF
CTOT
Between Input or
Output and Ground and
VBUS grounded
VR = 0V, f = 1MHz
60
pF
Capacitor
Total Capacitance
 2004 Semtech Corp.
2
6
V
10
pF
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STF202-22 and STF202-30
PROTECTION PRODUCTS
Typical Characteristics
ESD Clamping (8kV Contact)
ESD Clamping (15kV Air)
Typical Insertion Loss
Analog Crosstalk (D+ to D-)
0 dB
0 dB
-20 dB
-10 dB
-60 dB
-20 dB
0.030MHz
 2004 Semtech Corp.
2.0GHz
0.030 MHz
3
1 GHz
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STF202-22 and STF202-30
PROTECTION PRODUCTS
Applications Information
Device Connection
Figure 1 - STF202 Circuit Diagram
The STF202 is designed to provide termination, EMI
filtering and ESD protection for two USB I/O lines. The
equivalent circuit diagram is shown in Figure 1. The
device is connected as follows:
.
1 . Full-Speed Devices: For full-speed devices the pullup resistor is connected to the D+ line. Pin 1 is
connected to the voltage supply line (VBUS). The
input of the D+ line is routed into pin 3 and out of
pin 4. The input of the D- line is connected at pin 2
and the output at pin 5. Pin 6 is connected to
ground.
Figure 2 - STF202 Connection Diagram
(Full Speed Devices)
2 . Low-Speed Devices: For low speed devices the
pull-up resistor is connected to the D- line. Pins 1
is connected to the voltage supply line (VBUS). The
input of the D- line is connected at pin 3 with the
output taken at pin 4. The input of the D+ line is
connected to pin 2 and the output is at pin 5. Pin
6 is connected to ground.
1
6
2
5
3
4
USB Port Design Considerations
The Universal Serial Bus (USB) specification requires
termination and filtering components for proper operation. In addition, an open USB socket is vulnerable to
hazardous ESD discharges in excess of 15kV. These
discharges can may occur on the data lines or the
voltage bus. The STF202 is an easily implemented
solution 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.
Semtech provides a complete solution to simplify USB
port design (Figure 4). The STF201 and STF202
integrate all of the components necessary for line
termination, bidirectional EMI filtering, and ESD protection on downstream (STF201) or upstream (STF202)
ports. The SC5826 is a dual port power switch that
provides individual or ganged port switching, fault
reporting, and inrush current limiting as required by the
USB specification. The SC5205 ULDO provides a
stable voltage to the USB controller.
A simplified USB port is shown in Figure 3. 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. 15kΩ pull-down resistors are
used to identify a downstream port while an upstream
port is identified with a 1.5KΩ pull up resistor on either
the D+ (full speed devices) or the D- (low speed devices) data line. Capacitors are used to bypass high
frequency energy to ground and for edge rate control
of the USB signals. TVS diodes are added for ESD
protection of both (D+ and D-) data lines and the
voltage bus (VBUS). A power distribution switch and
voltage regulator provide the power management
functions of the port.
Board Placement and Layout Guidelines.
 2004 Semtech Corp.
Designing a USB hub to meet EMI and ESD immunity
requirements requires a combination of optimum
component placement, trace routing, and good circuit
design practices. Some general guidelines are given
below:
z
z
z
z
z
4
Avoid running D+ and D- signal line traces near high
speed clock lines or similar signal lines.
Avoid running critical signal lines near board edges.
Locate the USB controller chip near the USB
connectors.
Place the STF202 near the USB connector to
restrict transient coupling.
Minimize the path length between the USB connector and the STF202
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STF202-22 and STF202-30
PROTECTION PRODUCTS
Applications Information
Figure 3 - USB Port Components
Figure 4 - Typical USB Hub Design
 2004 Semtech Corp.
5
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STF202-22 and STF202-30
PROTECTION PRODUCTS
Outline Drawing - SOT23 6L
A
e1
2X E/2
D
DIM
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2X N/2 TIPS
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PLANE
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A
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aaa
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0.25
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(L1)
B
DETAIL
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SEATING
PLANE
C
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A
DIMENSIONS
INCHES
MILLIMETERS
MIN NOM MAX MIN NOM MAX
.057
.035
.000
.006
.035 .045 .051
.010
.020
.003
.009
.110 .114 .118
.060 .063 .069
.110 BSC
.037 BSC
.075 BSC
.012 .018 .024
(.024)
6
0°
10°
.004
.008
.008
1.45
0.90
0.00
0.15
.90 1.15 1.30
0.25
0.50
0.08
0.22
2.80 2.90 3.00
1.50 1.60 1.75
2.80 BSC
0.95 BSC
1.90 BSC
0.30 0.45 0.60
(0.60)
6
0°
10°
0.10
0.20
0.20
SIDE VIEW
C A-B D
NOTES:
1.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
Land Pattern -SOT23 6L
X
DIM
(C)
G
C
G
P
X
Y
Z
Z
Y
DIMENSIONS
MILLIMETERS
INCHES
(.098)
.055
.037
.024
.043
.141
(2.50)
1.40
0.95
0.60
1.10
3.60
P
NOTES:
1.
 2004 Semtech Corp.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
6
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STF202-22 and STF202-30
PROTECTION PRODUCTS
Marking Codes
Part Number
Marking
Code
STF202-22
222
STF202-30
230
Ordering Information
Part Number
Lead Finish
Qty per
Reel
R eel Size
STF202-22.TC
SnPb
3,000
7 Inch
STF202-30.TC
SnPb
3,000
7 Inch
STF202-22.TCT
Pb free
3,000
7 Inch
STF202-30.TCT
Pb free
3,000
7 Inch
Contact Information
Semtech Corporation
Protection Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
 2004 Semtech Corp.
7
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