The LMK62XX is a high-performance device. Therefore, pay careful attention to the device configuration and printed-circuit board (PCB) layout with respect to power consumption. The ground pin must be connected to the ground plane of the PCB through three vias or more, as shown in Figure 7-1, to maximize thermal dissipation out of the package.

Equation 1 shows the relationship between the PCB temperature around the LMK62XX and the junction temperature.

where

• T_B: PCB temperature around the LMK62XX
• T_J: Junction temperature of LMK62XX
• Ψ_JB: Junction-to-board thermal resistance parameter of LMK62XX (64.1°C/W without airflow)
• P: On-chip power dissipation of LMK62XX

To ensure that the maximum junction temperature of LMK62XX is below 105°C, it can be calculated that the maximum PCB temperature without airflow should be at 81°C or below when the device is optimized for best performance, resulting in maximum on-chip power dissipation of 0.36 W.