10.1.2 Power Dissipation

The ability to remove heat from the die is different for each package type, presenting different considerations in the PCB layout. The PCB area around the device that is free of other components moves the heat from the device to the ambient air. Performance data for JEDEC low-K and high-K boards are shown in Thermal Information. Using heavier copper increases the effectiveness in removing heat from the device. The addition of plated through-holes to heat-dissipating layers also improves the heatsink effectiveness.

Power dissipation depends on input voltage and load conditions. Power dissipation (P_D) is equal to the product of the output current multiplied by the voltage drop across the output pass element (V_IN to V_OUT). See Equation 6.

Equation 6.

Power dissipation can be minimized by using the lowest possible input voltage necessary to assure the required output voltage.