USBUF01P6 IPAD™ EMI filter and line termination for USB upstream ports Features ■ Monolithic device with recommended line termination for USB upstream ports ■ Integrated Rt series termination and Ct bypassing capacitors. ■ Integrated ESD protection ■ Small package size SOT-666IP Figure 1. Functional diagram (top view) 3.3 V Benefits Rt ■ EMI / RFI noise suppression ■ Required line termination for USB upstream ports ■ ESD protection exceeding IEC 61000-4-2 level 4 ■ High flexibility in the design of high density boards ■ ■ GND IEC 61000-4-2 level4: – 15 kV (air discharge) – 8 kV (contact discharge) Rt Applications EMI Filter and line termination for USB upstream ports on: ■ PC peripherals D3 Ct Description The USB specification requires upstream ports to be terminated with pull-up resistors from the D+ and D- lines to Vbus. For the implementation of USB systems, the radiated and conducted EMI should be kept within the required levels as stated by the FCC regulations. In addition to the requirements of termination and EMC compatibility, the computing devices are required to be tested for ESD susceptibility. MIL STD 883E-Method 3015-7: – Class 3, C = 100 pF, R = 1500 Ω – 3 positive strikes, 3 negative strikes (F = 1 Hz) USB Hubs 3.3 V D2 Tailored to meet USB 2.0 standard (low speed and full speed data transmission) ■ D4 Ct Complies with the following standards: ■ Rp D1 The USBUF01P6 provides the recommended line termination while implementing a low pass filter to limit EMI levels and providing ESD protection which exceeds IEC 61000-4-2 level 4 standard. The device is packaged in a SOT-666, which is the smallest available lead-frame package (45% smaller than the standard SOT323). TM: IPAD is a trademeark of STMicroelectronics February 2010 Doc ID 9883 Rev 7 1/9 www.st.com 9 Characteristics 1 USBUF01P6 Characteristics Table 1. Absolute maximum rating (Tamb = 25 °C) Symbol Parameter ± 16 ±9 ± 25 kV 150 °C -55 to +150 °C 260 °C -40 to + 85 °C Junction temperature Tj Storage temperature range Tstg TL Maximum lead temperature for soldering during 10 s at 5 mm for case Top Operating temperature range Table 2. Electrical characteristics (Tamb = 25 °C) Symbol Parameter VRM Stand-off voltage VBR Breakdown voltage VCL Clamping voltage IRM Leakage current I IF VF VCL VBR VRM V IRM IPP Peak pulse current αT Voltage temperature coefficient VF Forward voltage drop Rd Dynamic resistance Symbol 2/9 Unit IEC 61000-4-2 air discharge IEC 61000-4-2 contact discharge MIL STD 883E - Method 3015-7 ESD discharge VPP Value Slope = 1/Rd Test conditions Min. Typ. IPP Max. Unit 10 V 500 nA VBR IR = 1 mA IRM VRM = 3.3 V per line Rt Tolerance ± 10% 33 Ω Rp Tolerance ± 10% 1.5 kΩ Ct Tolerance ± 20% 47 pF 6 Doc ID 9883 Rev 7 USBUF01P6 2 Technical information Technical information Figure 2. USB standard requirements 3.3V 1.5k Rt Full-speed or Low-speed USB Transceiver D+ Twisted pair shielded Rt Zo = 90ohms 5m max D15k Ct Host or Hub port Rt D+ Ct 15k Ct Full-speed USB Transceiver Ct Hub 0 or Full-speed function Ct Low-speed USB Transceiver Ct Hub 0 or Low-speed function Rt D- FULL SPEED CONNECTION 3.3V 1.5k Ct Untwisted unshielded Rt 3m max DHost or Hub port 15k Ct Rt D+ D+ Rt Full-speed or Low-speed USB Transceiver Rt D- 15k LOW SPEED CONNECTION Application example Implementation of ST solutions for USB ports USBUF01P6 USBDF01W5 D2 Rt D+ D+ in Ct Rd D+ out D+ GND D+ Ct Ct Rt 3.3 V Rt Gnd DD- in Rt D+ CABLE Gnd Ct Rd Upstream port D1 Peripheral transceiver Downstream port Host/Hub USB por transceivert D- D- Rp D- out D3 3.3V D4 D- FULL SPEED CONNECTION Downstream port USBUF01P6 USBDF01W5 D2 Rt D+ D+ in Ct Rd D+ out D+ GND D+ Ct Ct Rt 3.3 V Rt Gnd DD- in Rt D- D1 CABLE Gnd Ct Rd Upstream port D+ Peripheral transceiver Figure 3. Host/Hub USB por transceivert 2.1 D- D- out Rp D3 3.3V D4 D- LOW SPEED CONNECTION Doc ID 9883 Rev 7 3/9 Technical information 2.1.1 USBUF01P6 EMI filtering Current FCC regulations require that class B computing devices meet specified maximum levels for both radiated and conducted EMI. ● Radiated EMI covers the frequency range from 30 MHz to 1 GHz. ● Conducted EMI covers the 450 kHz to 30 MHz range. For the types of device compliant with the USB standard, the most difficult test to pass is usually the radiated EMI test. For this reason the USBUF01P6 device aims to minimize radiated EMI. The differential signal (D+ and D-) of USB devices does not contribute significantly to radiated or conducted EMI because the magnetic field of each conductor cancels out the other. The inside of a PC product is very noisy and designers must minimize noise coupling from the different sources. D+ and D- must not be routed near high speed lines (clock spikes). Induced common mode noise can be minimized by running pairs of USB signals parallel to each other and running grounded guard trace on each side of the signal pair from the USB controller to the USBUF device. If possible, locate the USBUF device physically near the USB connectors. Distance between the USB controller and the USB connector must be minimized. The 47 pF (Ct) capacitors are used to divert high frequency energy to ground and for edge control, and are placed between the driver chip and the series termination resistors (Rt). Both Ct and Rt should be placed as close to the driver chip as is practicable. The USBUF01P6 ensures a filtering protection against electro-magnetic and radio frequency Interference thanks to its low-pass filter structure. This filter is characterized by the following parameters: ● Cut-off frequency ● Insertion loss ● High frequency rejection. Figure 4. USBUF01P6 typical attenuation curve Figure 5. Measurement configuration 0.00 dB --2.50 --5.00 --7.50 50Ω TEST BOARD UUx --10.00 --12.50 Vg --15.00 --17.50 --20.00 --22.50 --25.00 1.0M 3.0M 10.0M 30.0M 100.0M 300.0M 1.0G 3.0G f/Hz 4/9 Doc ID 9883 Rev 7 50Ω USBUF01P6 2.1.2 Technical information ESD protection In addition to the requirements of termination and EMC compatibility, computing devices are required to be tested for ESD susceptibility. This test is described in IEC 61000-4-2 and is already in place in Europe. This test requires that a device tolerates ESD events and remains operational without user intervention. The USBUF01P6 is particularly optimized to perform ESD protection. ESD protection is based on the use of device which clamps at: V CL = V BR + R d ⋅ I PP This protection function is split into 2 stages. As shown in Figure 6. The ESD strikes are clamped by the first stage S1 and then its remaining overvoltage is applied to the second stage through the resistor Rt. Such a configuration makes the output voltage very low. Figure 6. USBUF01P6 ESD clamping behavior Rg S1 Rd VPP Rd Vinput Rload Voutput VBR VBR Device to be protected USBUF01P6 ESD Surge Figure 7. S2 Rt Measurement board ESD SURGE Vin U 15kV Air Discharge TEST BOARD Vout To have a good approximation of the remaining voltages at both Vinput and Voutput stages, we give the typical dynamical resistance value Rd. Taking into account the following hypothesis: Rt>Rd, Rg>Rd and Rload>Rd, gives these formulas: R g ⋅ V BR + R d ⋅ V g Vinput = ---------------------------------------------Rg R t ⋅ V BR + R d ⋅ Vinput Voutput = --------------------------------------------------------Rt The calculation done for Vg = 8 kV, Rg = 330 Ω (IEC 61000-4-2 standard), VBR = 7 V (typ.) and Rd = 2 Ω (typ.) gives: Vinput = 55.48 V Voutput = 10.36 V Doc ID 9883 Rev 7 5/9 Technical information USBUF01P6 This confirms the very low remaining voltage across the device to be protected. It is also important to note that in this approximation the parasitic inductance effect was not taken into account. This could be a few tenths of volts during a few ns at the Vinput side. This parasitic effect is not present at the Voutput side due the low current involved after the resistance Rt. The measurements done hereafter show very clearly (Figure 8 and Figure 9) the high efficiency of the ESD protection: ● No influence of the parasitic inductances on Voutput stage ● Voutput clamping voltage very close to VBR (breakdown voltage) in the positive way and -VF (forward voltage) in the negative way Figure 8. Remaining voltage at both stages S1 (Vinput) and S2 (Voutput) during positive ESD surge Note: The USBUF01P6 acts not only for positive ESD surges but also for negative ones. For these kinds of disturbances it clamps close to ground voltage as shown in Figure 9. 6/9 Figure 9. Doc ID 9883 Rev 7 Remaining voltage at both stages S1 (Vinput) and S2 (Voutput) during negative ESD surge USBUF01P6 3 Package information Package information ● Epoxy meets UL94, V0 ● Lead-free package In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK® packages, depending on their level of environmental compliance. ECOPACK® specifications, grade definitions and product status are available at: www.st.com. ECOPACK® is an ST trademark. Table 3. SOT-666IP dimensions Dimensions Ref. b1 Typ. Max. Typ. Max. A 0.53 0.57 0.60 0.021 0.22 0.024 A3 0.13 0.17 0.18 0.005 0.007 0.007 b 0.17 L4 b Pin 1 D Inches Min. L1 L3 Millimeters b1 Min. 0.25 0.007 0.27 0.34 0.009 0.011 0.013 E1 D 1.50 1.66 1.70 0.059 0.065 0.067 E 1.50 1.65 1.70 0.059 0.065 0.067 E1 1.10 1.20 1.30 0.043 0.047 0.051 angle A L2 E A3 e e 0.50 0.020 L1 0.11 0.19 0.26 0.004 0.007 0.010 L2 0.10 0.23 0.30 0.004 0.009 0.012 L3 0.05 0.10 0.002 0.004 0.83 0.033 L4 angle° 8 10 12 8 10 12 Figure 10. SOT-666IP footprint (dimensions in mm) 0.50 0.30 0.99 0.21 0.62 2.60 1.40 0.20 Doc ID 9883 Rev 7 7/9 Ordering information 3.1 4 Mechanical specifications Lead plating Mat tin Lead plating thickness 7 µm min, 20 µm max Lead coplanarity 10 µm max Body material Molded epoxy Flammability UL94, V0 Ordering information Table 4. 5 USBUF01P6 Ordering information Order code Marking Package Weight Base qty Delivery mode USBUF01P6 U SOT-666IP 2.9 mg 3000 Tape and reel Revision history Table 5. Document revision history Date Revision September-2003 1 First issue. 01-Jun-2004 2 SOT-666 Internal Pad version package change. 08-Jun-2005 3 Minor format changes; no content changed. 10-Mar-2006 4 Footprint and dimension graphic improved in packaging information. Ecopack statement added. Reformatted to current standard. 16-Aug-2006 5 Updated SOT-666IP package dimensions in Table 3. 29-Aug-2006 6 Typing error in table 2 on page 2: change W and kW unit to Ω and kΩ unit. 7 Updated GND pin annotation in Figures 1 and 3. Added pin numbering indication to illustration and updated dimension values in Table 3. Updated mechanical specifications in Section 3.1. 18-Feb-2010 8/9 Changes Doc ID 9883 Rev 7 USBUF01P6 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such third party products or services or any intellectual property contained therein. UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT. UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY, DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK. Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any liability of ST. ST and the ST logo are trademarks or registered trademarks of ST in various countries. Information in this document supersedes and replaces all information previously supplied. The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners. © 2010 STMicroelectronics - All rights reserved STMicroelectronics group of companies Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America www.st.com Doc ID 9883 Rev 7 9/9