I have the TPS1663 evaluation board that uses the HTSSOP package. I am doing some experiments on the ability of the part to handle the inrush current in my system without hitting thermal shutdown. So far things look good. However, I want to use the VQFN packge in my actual system. The thermal metrics of the two packages are very similar - Rja of 31.4 °C/W for the VQFN and 32.2 °C/W for the HTSSOP. Other metrics are similarly close. Would you expect the thermal performance of the VQFN package to be fairly similar to the HTSSOP on the eval board?
Or, to put it another way, Figure 13 (of the TPS1663 datasheet) shows the thermal shutdown time vs. power dissipation of the HTSSOP package. Would you expect this graph to be very similar for the VQFN package?
