9.1 Recommended Thermal Operating Conditions

Table 9-1. Recommended Thermal Operating Conditions
Symbol	Parameter	Min	Max	Unit
T_{J_MPU}	Junction temperature range	-40	105	°C
T_{J_DDR3L}	Junction temperature range	-40	105	°C

Table 9-2. TFBGA427 Package Thermal Characteristics^(1)(2)(3)
Symbol	Parameter	Typ		Unit
R_JA	Junction-to-ambient thermal resistance	21		°C/W

Note:

R_JA = (T_{J_MPU} - T_A) / P_MPU, where T_A is the ambient temperature and P_MPU is the processor power consumption. The DDR3L SDRAM junction temperature is always lower than the MPU junction temperature.
According to the JEDEC JESD51-2 standard, with 2s2p board and 0 m/s air flow.
These values are not directly applicable to the board where the device is mounted. As per JEDEC standards, these parameters do not characterize the package itself but rather the package together with the PCB (4-layer or more) and other environmental factors (still air, etc.). For example, in still-air JEDEC-defined R_JA measurements, almost 70% of the power generated by the chip is dissipated from the test board, not from the package surfaces.