PROTECTION PRODUCTS

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PROTECTION PRODUCTS

STF201-22 & STF201-30

USB Downstream Port Filter & TVS

For EMI Filtering and ESD Protection

Description

Features

Schematic & Pin Configuration

Revision 9/2000

The STF201 is a combination EMI filter and line termi-

nation device with integrated TVS diodes for use on

downstream 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 downstream USB port. The STF201

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 22W or

30W 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 15kW

pull-down resistors complete the termination circuit on

each line. They are required by the USB specification

to identify the line as a downstream connection. The

47pF capacitors are used to bypass high frequency

energy to ground and for edge rate control of the USB

signals. Finally, the STF201 contains TVS diodes for

ESD protection of both (D+ & D-) data lines and the

voltage bus (V

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 STF201

minimizes required board space and increases system

reliability. The pin-out of the device allows easy imple-

mentation. The STF201 is suitable for use in USB

hubs, computers, peripherals, and portable devices.

Applications

Mechanical Characteristics

with integrated ESD protection

(D+ & D-) to IEC 61000-4-2 Level 4

S0T23-6L (Top View)

Circuit Diagram