SLAA462A May   2010  – April 2019

 

  1.   EM430F6137RF900 Reference Design Guide
    1.     Trademarks
    2. 1 Impedance Matching and Filter Design Principles
      1. 1.1 Filter and Balun Layout Best Practices
    3. 2 EM430F6137RF900 RF Front End
      1. 2.1 Changing the RF Front End For 315 MHz
      2. 2.2 Changing the RF Front End For 434 MHz
    4. 3 EM430F6137RF900 Schematic Tips and Tricks
      1. 3.1 Achieving Successful BSL Communication
      2. 3.2 Communicating in Spy-Bi-Wire (SBW) Mode
    5. 4 ETSI Compliance
      1. 4.1 Capacitors on TMS, TDI, and TDO Pins
    6. 5 References
  2.   Revision History

4 ETSI Compliance

Wire wound inductors perform better than multilayer inductors at high frequencies because the self-resonant frequency is higher. By using wire-wound instead of multilayer in the balun, it is possible to achieve better suppression of harmonic emission. Multilayer inductors are less expensive that wire-wound inductors. For an example of measurements based on the two different types of inductors, see DN017 - CC11xx 868/915 MHz RF Matching.

ETSI

ETSI EN 300 220 requires spurious emission above 1 GHz to be below –30 dBm. When using multilayer inductors, the highest PA setting that ensures compliance with ETSI is 0xC2. Using 0xC0, which is the CC430 PA setting resulting in maximum output power, results in a level of second harmonic which is at the ETSI limit. It is therefore recommended to use wire-wound inductors in the balun to achieve highest possible output power when seeking compliance with ETSI EN 300 220.