1. Power Line Network

2. 2 Confidential and Proprietary to Littelfuse, Inc. © 2006 Littelfuse, Inc. All rights reserved. POWER LINE NETWORK Power Line Network Application Guide Ethernet Power connection AC mains I/O Interface USB 1.1/2.0

3. 3 Confidential and Proprietary to Littelfuse, Inc. © 2006 Littelfuse, Inc. All rights reserved. POWER LINE NETWORK Block Diagram of Power Line Adapter Ethernet PHY µProcessor Power Management Ethernet AC power/data splitter Flash Memory MLV, Diode array Fuse, MOV Circuits highlighted in GREEN may experience electrical overstress (overcurrent, ESD, surge) and may require protection components to meet Regulatory standards or to ensure Reliable performance. USB PHY USB 2.0 MLV, PTC, PulseGuard Data Management (filter)

4. 4 Confidential and Proprietary to Littelfuse, Inc. © 2006 Littelfuse, Inc. All rights reserved. POWER LINE NETWORK Circuit Protection of AC Mains - Desktop Design Notes: Protection Application: Products that are directly connected to the AC mains (120 to 250VACrms) will be exposed to much more severe surge transients (lightning, load switching, etc.) and short circuit/overload conditions than on DC inputs. Because of this, the protection devices need to be more robust. Solution Description: As shown at the left (top), a cartridge or leaded fuse (Pico, 5x20mm, 2AG, 3AG, TE5/TR5) can be used for short circuit and overload current conditions. For surge protection, an MOV should be used. The MOV should be selected based on the expected severity (energy, voltage and peak pulse current) of the transient surge. The specific family (C-III, UltraMOV or LA) can be determined after the surge severity is understood. Companion Solutions: TVS diodes may also be considered for surge protection; selection will be based on peak pulse current and peak pulse power ratings.. Regulatory Issues: Standards will vary depending on the product to be protected. Examples include: IEC 61000-4-5 UL1414 UL1449 Unique Features: Does not apply. Application Warnings: When selecting the fuse, be sure to consider the expected temperature in the area around the fuse, as well as the in-rush currents. Failure to take these factors into account may result in premature or nuisance tripping of the fuse.

5. 5 Confidential and Proprietary to Littelfuse, Inc. © 2006 Littelfuse, Inc. All rights reserved. POWER LINE NETWORK Circuit Protection of USB 1.1 Design Notes: Protection Application: The data signals used in a USB 1.1 port vary between -0.5V to +0.5V, with a maximum data rate of 12Mbps. At this data rate, the capacitance of the suppressor needs to be taken into account. The signal lines to be protected from ESD include D+ and D-. The 5VDC power bus should be protected against ESD and overcurrent events. Solution Description: As shown at the left, a multilayer varistor is used on the power bus for ESD protect, and a PTC is used for resettable overcurrent protection. For the data lines, discrete multilayer varistors can be used for board layout flexibility, or to reduce part count, a single Diode array can be used. Companion Solutions: Other solutions within the LF portfolio exist in addition to these recommendations. For example, if the operating current on the power bus is higher or lower, an appropriately rated PTC can be chosen. Regulatory Issues: The IEC 61000-4-2 will be the most appropriate standard that applies for this port. It supplies a test method for verifying that the end product is not susceptible to ESD events. Unique Features: Does not apply. Application Warnings: Does not apply.

6. 6 Confidential and Proprietary to Littelfuse, Inc. © 2006 Littelfuse, Inc. All rights reserved. POWER LINE NETWORK Circuit Protection of USB 2.0 Design Notes: Protection Application: The data signals used in a USB 2.0 port vary between -0.5V to +0.5V, with a maximum data rate of 480Mbps. At this data rate, the capacitance of the suppressor needs to be minimized. The signal lines to be protected from ESD include D+ and D-. The 5VDC power bus should be protected against ESD and overcurrent events. Solution Description: As shown at the left, a multilayer varistor is used on the power bus for ESD protect, and a PTC is used for resettable overcurrent protection. For the data lines, discrete PulseGuard ® suppressors can be used for board layout flexibility, or to reduce part count, a single PulseGuard array can be used. Companion Solutions: Other solutions within the LF portfolio exist in addition to these recommendations. For example, if the operating current on the power bus is higher or lower, an appropriately rated PTC can be chosen. Regulatory Issues: The IEC 61000-4-2 will be the most appropriate standard that applies for this port. It supplies a test method for verifying that the end product is not susceptible to ESD events. Unique Features: Does not apply. Application Warnings: Does not apply.

7. 7 Confidential and Proprietary to Littelfuse, Inc. © 2006 Littelfuse, Inc. All rights reserved. POWER LINE NETWORK Circuit Protection of Ethernet Port Design Notes: Protection Application: The data signals used in an Ethernet port vary between 1.0V (100 and 1,000 BaseT) to 2.5V (10BaseT), with maximum data rates of 125Mbps and 12.5Mbps, respectively. At these data rates, the capacitance of the suppressor needs to be taken into account. The signal lines to be protected from ESD include T+/- and R+/-. Solution Description: As shown at the left, discrete multilayer varistors can be used for board layout flexibility, or to reduce part count, a single rail clamp array can be used. Companion Solutions: Other solutions within the LF portfolio exist in addition to these recommendations. For example, if the design engineer knows that no additional capacitance can be added to the system, the PulseGuard ® suppressor family can be consulted. Regulatory Issues: The IEC 61000-4-2 will be the most appropriate standard that applies for this port. It supplies a test method for verifying that the end product is not susceptible to ESD events. Unique Features: Does not apply. Application Warnings: This protection scheme is only for Ethernet ports that connect to a LAN. If the Ethernet network will include access to the outside of the building, then more stringent standards apply to take into account lightning surges. Please consult Littelfuse recommendations for Ethernet and Intrabuilding surge protection.