2.5.1 Maximum Stress Voltage for Latch-Up (MSV)

Since the advent of the JEDEC standard, the testing methodology has been digital CMOS centric. Over the years as power supply voltages increased, stressing at 1.5 x V_MAX became increasingly difficult if not impossible to do. Companies that produced high voltage products tested Latch-Up with levels less than 1.5 x V_MAX. Stressing at less than 1.5 x V_MAX was necessitated by the fact that transistor catastrophic breakdowns would be breached. So, in 2010, the JEDEC Latch-Up team decided to bring JESD78 up to common practice and created a new term called Maximum Stress Voltage for Latch-Up (MSV). MSV is generally a number less than a catastrophic transistor breakdown voltage and generally greater than the absolute maximum voltage (V_ABSMAX) listed in the device-specific data sheets.

Since the introduction of MSV, there have been numerous questions about how to determine the MSV value. MSV can be determined for each manufacturing process by either starting with one diode drop above the V_MAX and stepping the voltage up to catastrophic breakdown or choose a value near the catastrophic breakdown based on process characterization. There are no fixed rules for determining MSV, each user can determine and document the MSV as the standard is currently written. In an upcoming revision of JESD78, there will be additional informative guidance for determining MSV.