Datasheet STF202-30TC, STF202-22TC Datasheet (Semtech)

USB Upstream Port Filter & TVS
For EMI Filtering and ESD Protection

STF202-22

&

STF202-30

Objective - March 03, 2000

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DESCRIPTION

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

ESD protection

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 full­speed (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
contains TVS diodes for ESD protection of both (D+ &
D-) data lines and the voltage bus (V
diodes provide effective suppression of ESD voltages
in excess of 15kV (air discharge) and 8kV (contact
discharge) per IEC 1000-4-2, 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.

for one upstream USB port. The

termination, filtering

). The TVS

BUS

, and

FEATURES

•

Bidirectional EMI/RFI filtering and line termination
with integrated ESD protection

•

ESD protection for USB power (V
lines (D+ & D-) to

•

Filtering and termination for two USB data lines

•

Different series resistors for impedance matching

•

Low TVS operating voltage (5.25V)

•

Low leakage current

•

Small SOT-23 6L package

•

Solid-state technology

IEC 1000-4-2 Level 4

) and data

BUS

MECHANICAL CHARACTERISTICS

•

EIAJ SOT-23 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

•

Peripherals

•

Servers, Desktop, Notebook, and Handheld
Computers

ORDERING INFORMATION

Part Number Series

Resistor

STF202-22.TC 22

Ω

Qty per

Reel

3,000 7”

Reel Size

STF202-30.TC 30

COMPONENT VALUES

Series

Resistor

)

(R

S

STF202-22 22
STF202-30 30

Tolerance ±10% ±10% ±20%

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

Ω
Ω

Pull Up

Resistor

(RPU)

1.5k

1.5k

Ω
Ω

Termination

Capacitor

(C)

47
47

SCHEMATIC & PIN CONFIGURATION

SOT-23 6L (Top View)

Ω

3,000 7”

STF202-22

USB Upstream Port Filter & TVS
For EMI Filtering and ESD Protection

Objective - March 03, 2000

STF202-30

MAXIMUM RATINGS

Rating Symbol Value Unit

Steady-State Power P 100 mW

&

ESD Air Discharge per IEC 1000-4-2 V
ESD Contact Discharge per IEC 1000-4-2 V
Lead Soldering Temperature (10 seconds) T
Operating Temperature T
Storage Temperature T

PP

PP

L

stg

j

16 kV
10 kV

260 °C

-40 to +125 °C

-55 to +150 °C

ELECTRICAL CHARACTERISTICS (T = 25ºC Unless Otherwise Noted)

STF202-xx

Parameter Symbol Conditions Minimum Nominal Maximum Units

TVS Reverse Stand-Off Voltage V
TVS Reverse Breakdown Voltage V
TVS Reverse Leakage Current I

RWM

BR

R

It = 1mA 6 V

V

= 5.25V, T=25°C

RWM

Between V

pin and

BUS

ground

TVS Reverse Leakage Current I

R

V

= 3.3V, T=25°C

RWM

Between any data

(D+, D-) pin and ground

Total TVS Junction Capacitance C

j

Between I/O pins and

10 pF

Gnd, each device

V

= 0V, f = 1MHz

R

Series Resistor
Series Resistor

(STF202-22)
(STF202-30)

Pull Up Resistor R

R

S

R

S

UP

Each Line 20 22 24
Each Line 27 30 33
Each Line 1.35 1.5 1.65

Capacitor C Each Line 47 pF

5.25 V

5µA

1µA

Ω
Ω

k

Ω

Total Capacitance C

TOT

Between I/O pins and

60 pF

Gnd, each line

V

= 0V, f = 1MHz

R

MARKING CODES

Part Number Marking Code

STF202-22 222
STF202-30 230

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

Objective - March 03, 2000

TYPICAL CHARACTERISTICS

USB Upstream Port Filter & TVS
For EMI Filtering and ESD Protection

ESD Clamping (15kV Air)ESD Clamping (8kV Contact)

STF202-22

&

STF202-30

Insertion Loss Characteristics Analog Crosstalk (D+ to D-)

0 dB

-10 dB

-20 dB

0.030MHz 2.0GHz

0 dB

-20 dB

-60 dB

0.030 MHz 1 GHz

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

USB Upstream Port Filter & TVS
For EMI Filtering and ESD Protection

Objective - March 03, 2000

APPLICATIONS INFORMATION

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:

pull-up resistor is connected to the D+ line. Pin 1
is connected to the voltage supply line (V
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.

•

Low-Speed Devices:

pull-up resistor is connected to the D- line. Pins 1
is connected to the voltage supply line (V
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.

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
& EMI filter requirements of the USB specification
revision 1.1. It also provides ESD protection to IEC
61000-4-2, level 4.

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+ & D-) data lines and the voltage bus (V
power distribution switch and voltage regulator provide
the power management functions of the port.

Semtech provides a complete solution to simplify USB
port design (Figure 4). The STF201 & STF202

For full-speed devices the

). The

BUS

For low speed devices the

). The

BUS

BUS

). A

STF202-22

&

STF202-30

Figure 1 - STF202 Circuit DiagramDevice Connection

.

Figure 2 - STF202 Connection Diagram

(Full Speed Devices)

1

2

34

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.

Board Placement & Layout Guidelines.

Designing a USB hub to meet EMI & ESD immunity
requirements requires a combination of optimum
component placement, trace routing, and good circuit
design practices. Some general guidelines are given
below:

•

Avoid running D+ & 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

6

5

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

Objective - March 03, 2000

APPLICATIONS INFORMATION

USB Upstream Port Filter & TVS
For EMI Filtering and ESD Protection

STF202-22

&

STF202-30

Figure 3 - USB Port Components

Figure 4 - Typical USB Hub Design

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320

Objective - March 03, 2000

OUTLINE DRAWING SOT23-6L

USB Upstream Port Filter & TVS
For EMI Filtering and ESD Protection

STF202-22

&

STF202-30

LAND PATTERN SOT23-6L

© 2000 SEMTECH CORP. 652 MITCHELL ROAD NEWBURY PARK CA 91320