To prevent thermal shutdown, TJ must be
less than 150°C. The HTSSOP package has good thermal impedance. However, the PCB layout is
very important. Good PCB design helps 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 no heat sinks are attached to the PCB on the other side of the package.
- Add as many thermal vias as possible directly under the package ground pad to optimize the thermal conductivity of the board.
- To prevent solder voids, ensure that all thermal
vias are either plated shut or plugged and capped on both sides of the board. To maintain
reliability and performance, the maintain at least 85% solder coverage.