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.

Table 19. Power Limit Table Entries for affected Launchpads¶
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

CC1312PSIP FCC Module Certification¶

In order to re-use the FCC RF Module certification of CC1312PSIP on Sub 1GHz channels, an application using TI 15.4 stack (in Frequency Hopping mode) or TI Wi-SUN FAN stack needs to limit the transmit power to the following values. If you set the transmit power to more than the values stated in the following tables, you need to re-certify the product and will likely pass only with duty cycling.

Table 20. Power Limits for TI 15.4 stack on 20 dBm PA¶
Stack	Tx Power	Additional Condition
TI 15.4 Stack	19 dBm	If you only use channels between 908.2-927MHz
TI 15.4 Stack	16 dBm	If you include any channel between 902.2-908MHz

Table 21. Power Limits for TI Wi-SUN FAN Stack on 20 dBm PA¶
Stack	Tx Power	Additional Condition
TI Wi-SUN FAN Stack	19 dBm	If you duty cycle with 60ms out of 100ms in TX
TI Wi-SUN FAN Stack	17 dBm	Without duty cycling

If you are using other certified PHYs, you will find the limits in the following tables.

Table 22. Power limits for WB-DSSS PHYs on 20 dBm PA¶
Phy	Tx Power	Additional Condition
WB-DSSS All Phys	15 dBm	Under all conditions

Table 23. Power limits for MIOTY PHYs on 20 dBm PA¶
Phy	Tx Power	Additional Condition
MIOTY	20 dBm	If you duty cycle with 60ms out of 100ms in TX
MIOTY	19 dBm	Without duty cycling

If you are using the 14 dBm port, the following table provides the maximum TX power that you can set during transmission in order to re-use the FCC RF Module certification of CC1312PSIP on Sub 1GHz channels. It is not necessary to use duty cycling or modify channel plans in this case.

Table 24. Power limits for all certified PHYs on 14 dBm PA¶
Phy/Stack	Tx Power
TI 15.4 Stack	12.5 dBm
TI Wi-SUN FAN Stack	12.5 dBm
WB-DSSS PHYs	12.5 dBm
MIOTY PHYs	12.5 dBm