2 Simulation and Measurement Results

There are multiple properties of an LDO which influence thermal performance, including the following:

1. Shape and area of the pass FET
2. Shape and area of the die
3. Die thickness
4. Die attach thickness
5. Die attach conductivity
6. Mold compound conductivity
7. Metal layer deposition

With the preceding discussion in mind, the TPS748 die (Figure 2-1) was redesigned (Figure 2-2) to reduce the die area by 72% while maintaining nearly identical thermal performance.

For the redesigned TPS748, the die attach and mold compound were improved and incorporated into the design.