SMA SM4TY 400W Automotive Transil™ STMicroelectronics SMA SM4TY 400W Automotive Transil™ series protects sensitive automotive circuits against surges defined in ISO 7637-2 and against electrostatic discharges according to ISO 10605. The planar technology makes it compatible with high-end circuits where low leakage current and high junction temperature are required to provide reliability and stability over time. STMicroelectronics SM4TY devices are packaged in SMA (SMA footprint per IPC 7531 standard).