FCC Certification Considerations

This section will cover important TI 15.4-Stack application changes which may be required to achieve FCC certification given a specific hardware design.

Power Limiting Table Adjustment

Some LaunchPad designs are known to fail FCC certifications at higher 2.4 GHz channels due to increased second harmonic transmissions. In order to work around this issue, a power limiting table PowerLimitTableIeee has been initialized inside mac_user_config.c to help limit the maximum transmission level for channels which are known to be affected.

/*
* For CC1352P_2_LAUNCHXL, set ch25 to 19dBm and ch26 to 15dBm
*
* For LP_CC2652RSIP, set all ch to 5dBm except for 26, set ch26 to 2dBm
*
* For LP_CC2652PSIP, set ch26 to 2dBm and set other ch to 10dBm
*/
int8_t PowerLimitTableIeee[RF_CONFIG_IEEE_PL_NO_CHANNELS] =
{
    20,    //20dBm max for Channel = 11
    20,    //20dBm max for Channel = 12
    20,    //20dBm max for Channel = 13
    20,    //20dBm max for Channel = 14
    20,    //20dBm max for Channel = 15
    20,    //20dBm max for Channel = 16
    20,    //20dBm max for Channel = 17
    20,    //20dBm max for Channel = 18
    20,    //20dBm max for Channel = 19
    20,    //20dBm max for Channel = 20
    20,    //20dBm max for Channel = 21
    20,    //20dBm max for Channel = 22
    20,    //20dBm max for Channel = 23
    20,    //20dBm max for Channel = 24
    19,    //19dBm max for Channel = 25
    15,    //15dBm max for Channel = 26
};

The example above provides the correct power limit table changes necessary based on existing FCC certification of the LAUNCHXL-CC1352P-2, and a comprehensive list of other affected LaunchPads is provided in the table below. If FCC certification is desired for any of these LaunchPads, their respective mac_user_config.c files’s PowerLimitTableIeee must be modified to compensate.

LaunchPad	Channel	Entry
CC1352P_2_LAUNCHXL	25, 26	19, 15
LP_CC2652RSIP	26	2
LP_CC2652PSIP	11-25, 26	10, 2
LP_CC2651R3SIPA	26	1

Note

Power limitation values will vary slightly for each custom hardware design, thus caution should be taken to identify the optimal values during FCC certification and modify the table accordingly