Short and long-term safe operating area considerations in LDMOS transistors

Lateral DMOS transistors are widely used in mixed-signal IC circuit designs, particularly where power handling is important. This paper views the LDMOS from a power-handling perspective, considering both design and characterization aspects. The complex nature of the LDMOS safe operating area (SOA) can be dealt with by considering long-term and short-term operating conditions. Long-term conditions are covered by a hot carrier SOA, and short-term conditions are further sub-divided into electrical SOA and thermal SOA. Characterization examples of the various kinds of SOA are given.