LPD-SOM-EU-SHIELD

DM3730/AM3703 Torpedo + Wireless SOM EU Emissions Shield Cover Application Note 616 Logic PD // Products Published: February 2016 This document contains valuable proprietary and confidential information and the attached file contains source code, ideas, and techniques that are owned by Logic PD, Inc. (collectively “Logic PD’s Proprietary Information”). Logic PD’s Proprietary Information may not be used by or disclosed to any third party except under written license from Logic PD, Inc. Logic PD, Inc. makes no representation or warranties of any nature or kind regarding Logic PD’s Proprietary Information or any products offered by Logic PD, Inc. Logic PD’s Proprietary Information is disclosed herein pursuant and subject to the terms and conditions of a duly executed license or agreement to purchase or lease equipment. The only warranties made by Logic PD, Inc., if any, with respect to any products described in this document are set forth in such license or agreement. Logic PD, Inc. shall have no liability of any kind, express or implied, arising out of the use of the Information in this document, including direct, indirect, special or consequential damages. Logic PD, Inc. may have patents, patent applications, trademarks, copyrights, trade secrets, or other intellectual property rights pertaining to Logic PD’s Proprietary Information and products described in this document (collectively “Logic PD’s Intellectual Property”). Except as expressly provided in any written license or agreement from Logic PD, Inc., this document and the information contained therein does not create any license to Logic PD’s Intellectual Property. The Information contained herein is subject to change without notice. Revisions may be issued regarding changes and/or additions. © Copyright 2016, Logic PD, Inc. All Rights Reserved. PN 1028149A Logic PD, Inc. All Rights Reserved. i AN616 DM3730/AM3703 Torpedo + Wireless SOM EU Emissions Shield Cover Revision History REV EDITOR DESCRIPTION APPROVAL DATE A JMC -Initial Release JMC, AF, BSB 2/17/16 PN 1028149A Logic PD, Inc. All Rights Reserved. ii AN616 DM3730/AM3703 Torpedo + Wireless SOM EU Emissions Shield Cover Table of Contents 1 2 3 4 5 6 7 Introduction .................................................................................................................... 1 Scope .............................................................................................................................. 1 How to Identify Your SOM ............................................................................................... 1 EU Spurious Emissions Results ........................................................................................ 1 Shield Cover Description and Ordering Information ........................................................ 2 Shield Cover Installation ................................................................................................. 2 Summary ......................................................................................................................... 3 PN 1028149A Logic PD, Inc. All Rights Reserved. iii AN616 DM3730/AM3703 Torpedo + Wireless SOM EU Emissions Shield Cover 1 Introduction This application note describes the application and installation of a mechanical electromagnetic emissions shield cover for the -32 model Torpedo + Wireless SOM. This shield cover is necessary in order for the SOM to comply with the European Union (EU) standards for spurious emissions. 2 Scope This document, and the shield cover described herein, only apply to the -32 model of the DM3703/AM3703 Torpedo + Wireless (T+W) SOM. Further, this shield cover is only necessary when using the -32 model T+W SOM in regions covered by EU standard EN 301 893 v1.8.1:2015. This shield cover is not required for products deployed with the -32 model T+W SOM in the USA or Canada. 3 How to Identify Your SOM You can determine which SOM you have by referencing the model number on the label of the SOM. Figure 1 shows the beginning of the model number in the 4th line of the label. The SOM seen in this example is a -30 T+W SOM. A -32 T+W SOM will include “-32” as the final characters on this 4th line. Additional information on the model number can be found in the Logic PD Model Number Explanation & Decoder White Paper 2931. Figure 1: DM37x Torpedo + Wireless SOM Label 4 EU Spurious Emissions Results During EU standards testing of the -32 model T+W SOM, it was found that the SOM did not comply with the receiver spurious emissions limit specified in section 4.6 of standard EN 301 893 v1.8.1:2015. This testing was performed on WiFi channel 48 where a spectral peak at approximately 13.1GHz was measured above the allowable spectral limit. Further testing verified that the out of spec spurious emission was emanating from the case of the radio module on the SOM. The spurious emission was not found on the antenna ports of the SOM. The shield cover described in section 5 was designed as a custom cover to be fitted over the radio module on the SOM to suppress the offending spurious emission. 1 https://support.logicpd.com/downloads/601/ PN 1028149A Logic PD, Inc. All Rights Reserved. 1 AN616 DM3730/AM3703 Torpedo + Wireless SOM EU Emissions Shield Cover 5 Shield Cover Description and Ordering Information The shield cover is a single piece metal cap that snaps in place over the metal case of the radio module that resides on the T+W SOM assembly. An outline drawing of this shield cover is shown below in Figure 2. The shield cover is an accessory part that can be ordered from Logic PD’s authorized distributors (Digi-Key ). The part number assigned to this shield cover is LPD-SOM-EU-SHIELD. Figure 2: Shield Cover Outline Drawing 6 Shield Cover Installation The shield cover is installed by snapping it in place over the radio module on the T+W SOM assembly as shown in Figure 3. The correct orientation of the shield cover is important to ensure proper shielding of the emissions coming from the radio module. As shown in Figure 3, the side of the shield cover that contains the two latching dimples needs to be positioned on the outside edge of the SOM assembly. To install the shield cover, position it squarely over the metal case of the radio module and press down evenly on the shield. When the shield is fully seated you’ll hear the three latching dimples snap into place as the cover attaches to the radio module metal case. Figure 3: Shield Cover Installation and Orientation PN 1028149A Logic PD, Inc. All Rights Reserved. 2 AN616 DM3730/AM3703 Torpedo + Wireless SOM EU Emissions Shield Cover 7 Summary Information in this application note has been provided to assist customers using the -32 model Torpedo + Wireless SOM in regions covered by the European Union electromagnetic emissions standards. For customers needing additional information about this EU emissions shield cover application, please submit a post to the Logic PD Technical Discussion Group2 forum. 2 https://support.logicpd.com/TDGForum.aspx PN 1028149A Logic PD, Inc. All Rights Reserved. 3