Transient protection for a 15.3 V rail
The 1.5SMC18CA-M3/57T: Its 17.1 V minimum breakdown voltage ensures the device starts conducting before the protected circuit's absolute maximum is reached, while the 25.2 V maximum clamping voltage at the 59.5 A peak pulse current (10/1000 µs waveform) limits the voltage spike the load sees.
Package and temperature envelope
Housed in the DO-214AB (SMC) package, the device is surface-mount with a standard footprint shared across many 1.5 kW TVS diodes. The operating junction temperature range spans -65 °C to 150 °C, covering military cold-soak and under-hood automotive hot spots. The wide range means no derating is needed for most industrial and telecom environments; the junction temperature limit is the die attach and molding compound rating, not the silicon itself.
The base product number is 1.5SMC18, so the -M3/57T suffix denotes the specific packaging and reel configuration (Tape & Reel).