To prevent thermal shutdown, TJ must be
less than 175°C. If the output current is high, the power dissipation can be large.
However, the PCB layout is very important. A good PCB design optimizes heat
transfer, which is essential for the long-term reliability of the device.
- Maximize the copper coverage on the PCB to increase the thermal conductivity of the board. The major heat-flow path from the package to the ambient is through the copper on the PCB. Maximum copper is extremely important when no heat sinks are attached to the PCB on the other side of the board opposite the package.
- Add as many thermal vias as possible directly under the package ground pad to optimize the thermal conductivity of the board.
- All thermal vias must either be plated shut or plugged and capped on both sides
of the board to prevent solder voids. To ensure reliability and performance, the
solder coverage must be at least 85%.