Clamping and breakdown characteristics
The device triggers at a minimum breakdown voltage of 19 V, clamping the transient to 27.7 V maximum at the rated 54.2 A peak pulse current. This 8.7 V window between standoff and clamp means the protected rail sees less than a 1.6× overvoltage during a surge — relevant for sensitive 15 V supply inputs on DC-DC converters or PLC I/O modules. Rated for a 1500 W peak pulse power, the 1.5SMC20A-M3/9AT handles the energy of a typical 10/1000 µs surge waveform without derating at 25 °C ambient.
Package and board integration
Housed in a DO-214AB (SMC) surface-mount package, the part mates with the standard SMCJ footprint. The JEDEC-compliant package outline allows reflow soldering with lead-free profiles; the cathode band identifies the unidirectional orientation for the single-channel protection. The package body is rated for the full -65 °C to 150 °C operating junction temperature, so the TVS can sit near hot components like power inductors or MOSFETs without derating.