Conformity - November 2008 - (Page 32) opening and a metallic shield. It connects to the PCB only at the USB connector via a gasket. There is no connection of the shield on the left side, at which the LCD connects to the PCB. Thus, a relatively large voltage can be induced. This voltage would be partially coupling into the LCD connection wires, making the measurement of this voltage a relevant target for verifying the ESD generator model. The metallic and lossy blocks were used for the full wave model shown in Figure 9. The discrete blocks are the battery, connecting cables, the main PCB, the LCD display, a shield and the USB connector. The shield forms a resonator, as it is only connected on the USB connector side. The voltage between the shield and the PCB has been selected as measurerand. A microscope view reveals the details of the coax cable connections in Figure 10 and Figure 11. The outer conductor of the coax cable is attached to the PCB, and the inner conductor is attached to the metal shield of the Figure 6: Comparison of simulated and measured spectra of the induced loop voltage Figure 9: Model of the handheld device structure Figure 7: Small handheld device having a cable attached Frequency [GHz] Figure 10: Side view of the hand held device showing the entry of the coax cable into the player Figure 8: Measured and simulated current in the attached cable 32 Conformity november 2008 Figure 11: Details of the coax cable connection
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