AN650

AN650 S i468 X S CHEMATICS AND L AYOUT G UIDE 1. Introduction This document provides: General Si468x design guidelines, which include schematics, layout, and BOM Si468x FM/FMHD/T-DMB/DAB antenna/matching network design guidelines 2. Si468x WLCSP Schematic and Layout 2.1. Schematic Design and Component Selection This section shows the minimal schematic and layout options required for optimal performance of Si468x in the WLCSP package. Population options are provided to mitigate system noise, to use analog audio output, and to operate the Si468x with crystal. Rev. 0.5 10/13 Copyright © 2013 by Silicon Laboratories AN650 Free Datasheet http://www.datasheet4u.net/ AN650 2.1.1. Schematic Design Figure 1. Si468x WLCSP Schematic Design 2 Rev. 0.5 Free Datasheet http://www.datasheet4u.net/ AN650 2.1.2. Component Selection The L1, L2 and C13 are external components for matching purposes. This configuration is set up for achieving the best conducted sensitivity result. It is shown here for demonstrating best possible layouts. But when designing with a specific antenna, the exact matching network and component values are referred to in each individual antenna selection in “4. Antenna and Matching Network Design and Layout” . L1 and L2 are front-end matching inductors. Inductors L1 and L2 are selected to maximize the voltage gain across the DAB/T-DMB band. L1 and L2 should be selected with a Q of 15 to 20 in the range of 100 MHz to 200 MHz. Place L1 and L2 as close as pos...