The STF203 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 STF203 is an easily implemented solution for meeting the requirements of revision 1.1 of the Universal Serial Bus specification. Line termination is achieved with series resistors on both the D+ and D- USB lines. The value of series resistance added to the output impedance of the USB driver must be as close to possible to the 45Ω characteristic impedance of the cable (90Ω balanced) to minimize transmission line reflections. They are available with resistor values of 15Ω (STF203-15), 22Ω (STF203-22), and 33Ω (STF203-33). The 1.5kΩ pull-up 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 D- line) device. The 47pF capacitors are required to bypass high frequency energy to ground and to control the edge rate of the USB signals. The TVS diodes provide ESD protection of both (D+ & D-) data lines and the voltage bus (VBUS)
The STF203 is a combination EMI filter and line termination device featuring integrated TVS diodes designed for use on upstream USB ports. It utilizes proprietary technology to integrate passive components and TVS diodes into a single SC70-6L package, providing termination, filtering, and ESD protection for one port in compliance with USB specification revision 1.1.
The device offers bidirectional EMI/RFI filtering and line termination with integrated ESD protection rated up to IEC 61000-4-2 Level 4 (15kV air discharge, 8kV contact discharge). It is available in three variants based on series resistance values: STF203-15 (15Ω), STF203-22 (22Ω), and STF203-33 (33Ω).
| Package Type | SC70-6L |
|---|---|
| ESD Protection (Air Discharge) | 15kV |
| Operating Temperature Range | -40 to +125 °C |
| TVS Reverse Stand-Off Voltage (Typical) | 5.25 V |
| Series Resistance STF203-15 | 15 Ω |
| Series Resistance STF203-33 | 33 Ω |
The device provides ESD protection of both D+ and D- data lines to IEC 61000-4-2 Level 4.
The series includes models with series resistors of 15Ω, 22Ω, and 33Ω.