Hardware, software, electronics

To reduce time-to-market and component count, power management ICs with integrated power transistors such as National’s new SIMPLE SWITCHER® regulators (LM5576, LM25576, and others) are often preferred over controllers with external FETs. However, with the power transistor onboard, it’s important to do careful thermal analysis of the power IC to make sure the silicon temperature does not exceed the maximum allowable junction temperature. Integrated circuits are rated up to a maximum ‘die’ temperature. Operation at higher temperatures will put the IC out of specification and possibly destroy it. There are three main ways of thermally analyzing a given design. The following article explains the different approaches, and discusses the precision of each approach. Read more...