STF202-22 & STF202-30 USB Upstream Port Filter & 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 22 or 30 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 1.5k 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+ & 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 ! ! ! ! ! ! ! with integrated ESD protection ESD protection for USB power (VBUS) and data lines (D+ & D-) to IEC 61000-4-2 Level 4 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 ! ! ! ! EIAJ SOT23-6L package Molding compound flammability rating: UL 94V-0 Marking : Marking Code Packaging : Tape and Reel per EIA 481 Applications ! ! ! ! ! ! Circuit Diagram USB Hubs Portable electronics Cellular Handsets Modems Peripherals Servers, Desktop, Notebook, and Handheld Computers Schematic & PIN Configuration . S0T23-6L (Top View) Revision 4/19/01 1 www.semtech.com STF202-22 & STF202-30 PROTECTION PRODUCTS Absolute Maximum Rating R ating Symbol Value Units Steady-State Power Pp k 100 mW ESD Air Discharge per IEC 61000-4-2 V PP 16 kV ESD Contact Discharge per IEC 61000-4-2 VFP 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=25C Between VBUS pin and Ground 5 A T VS Reverse Leakage Current IR VRWM = 3.3V, T=25C Between any data (D+, D-) pin and Ground. 1 A 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 Series Resistance (STF202-30) RS Each Line 27 30 33 Pull Up Resistance RUP Each Line 1.35 1.5 1.65 k C Each Line 47 pF CTOT Between Input or Output and Ground and VBUS grounded VR = 0V, f = 1MHz 60 pF Capacitor Total Capacitance 2001 Semtech Corp. 2 6 V 10 pF www.semtech.com STF202-22 & 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 2001 Semtech Corp. 2.0GHz 0.030 MHz 3 1 GHz www.semtech.com STF202-22 & 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 & 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 & 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. 15k pull-down resistors are used to identify a downstream port while an upstream port is identified with a 1.5K 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 (VBUS). A power distribution switch and voltage regulator provide the power management functions of the port. Board Placement & Layout Guidelines. 2001 Semtech Corp. 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: " " " " " 4 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 www.semtech.com STF202-22 & STF202-30 PROTECTION PRODUCTS Applications Information Figure 3 - USB Port Components Figure 4 - Typical USB Hub Design 2001 Semtech Corp. 5 www.semtech.com STF202-22 & STF202-30 PROTECTION PRODUCTS Outline Drawing - SOT23-6L Land Pattern - SOT23-6L 2001 Semtech Corp. 6 www.semtech.com STF202-22 & STF202-30 PROTECTION PRODUCTS Marking Codes Part Number Marking Code STF202-22 222 STF202-30 230 Ordering Information Part Number Series R esister Qty per R eel R eel Size STF202-22.TC 22 3,000 7 Inch STF202-30.TC 30 3,000 7 Inch Contact Information Semtech Corporation Protection Products Division 652 Mitchell Rd., Newbury Park, CA 91320 Phone: (805)498-2111 FAX (805)498-3804 2001 Semtech Corp. 7 www.semtech.com