01What separates an automotive-grade MOSFET from an industrial one?
The qualification regime. Automotive parts are screened and stress-tested to AEC-Q101 (temperature cycling, HTRB, H3TRB), with tighter lot-to-lot consistency and failure-rate requirements; their datasheets usually state a higher junction-temperature limit and fuller SOA data. Beyond the mark, check derating curves across the temperature range, failure-mode predictability and lot consistency. On category pages, filter by Product Grade and pick Automotive; LV/MV MOSFETs also carry an Automotive (Y/N) column.
02What does the "-12" suffix on a wafer part number mean, and what extra parameters does bare-die selection need?
"-12" marks a 12-inch wafer format; for most part numbers, the same name without it is the 8-inch version. The gross-die range in the guide is counted per 8" wafer, so confirm the wafer format first, then run cost from gross die. Bare-die selection also checks process and channel configuration, RDS(on) at your gate-drive VGS grade, die size, thickness grade and ESD integration — and never infers die RDS(on) from a packaged part, since package resistance is a real share.
03Which voltage ranges do SGT and superjunction MOSFETs cover, and how do I pick the route?
SGT adds a shield electrode beside the trench gate to cut gate-drain capacitance and the Miller effect, giving low switching loss; it covers low-to-medium voltage (about 12V–230V in the catalog) for synchronous rectification, battery management, motor drive and load switches. Superjunction uses vertical charge balance to raise the rating while keeping on-resistance low, covering roughly 300V–800V for off-line supplies, adapters and industrial power. The routes complement rather than replace each other: low-voltage high-frequency designs weigh switching loss and drive matching; medium-to-high voltage designs weigh voltage margin and avalanche energy.
04When does avalanche energy (EAS) have to be checked?
Whenever the turn-off path contains an inductive load — motors, relays, solenoids — or line transients and abnormal shutdown could push VDS past the rating, EAS must be checked. It states how much energy the device can absorb during inductive turn-off, a key reliability figure at high voltage that conduction and switching-loss numbers do not capture; automotive designs need the same check. EAS is a single-pulse rating; repetitive avalanche needs separate assessment. Both HV and LV/MV MOSFET categories on this site expose an EAS_Max (mJ) column for filtering.
05Should HV MOSFET voltage margin be set against the steady bus or the switching spike?
Both — set the margin against the stacked peak. Start from the highest steady bus: the line-voltage upper limit, plus ripple on a PFC output. Add the switching spike from leakage inductance and parasitics, taken from measurement or simulation rather than a rule of thumb. Then keep extra margin for temperature and aging. Choosing the VDS class from steady bus voltage alone is a common HV MOSFET mistake. The HV MOSFET category on this site spans roughly 300V–800V and filters directly on VDS_Max.
06IGBT module or discrete?
First check whether the power tier and topology are standard. Low-power or single-phase designs (roughly below 20 A) suit discrete IGBTs with external drivers and free layout; three-phase designs above about 30 A suit modules — shared baseplate cooling, low parasitic inductance, isolation and creepage already engineered. Then ask two more questions: can the team develop its own drive and protection circuitry, and is maintenance a whole-module swap or a single-device repair? Listed discretes cover about 15A~150A, modules 15A~950A.
07How to trade VCE(sat) against switching loss?
Within one voltage class, a part with lower VCE(sat) usually has a longer turn-off tail and higher Eoff. Drives at 4~16 kHz carrier lean towards low VCE(sat); high-frequency welders and UPS links lean towards low Eon+Eoff. Sum conduction and switching loss at the real carrier frequency, then check junction temperature through Rth(J-C). Align test conditions before comparing: VCE(sat) moves with gate voltage and junction temperature, and switching loss is usually quoted at Tj=125°C, so figures taken under different conditions are not directly comparable.