To prevent thermal shutdown, TJ must be
less than 150°C. If the output current is very high, the power dissipation can be
large. The HTSSOP package has good thermal impedance. However, the PCB layout is
very important. Good PCB design can optimize heat transfer, which is absolutely
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 there are not any heat sinks 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.
- Make sure all thermal vias are either be plated
shut or plugged and capped on both sides of the board to prevent solder voids.
To make sure of reliability and performance, the solder coverage must be at
least 85%.