What the 1500W peak pulse rating means for your protection design
The 1.5SMC150AHE3/9AT: The 128 V reverse standoff voltage means the diode stays off below that DC bus level; above it, clamping triggers at 143 V minimum breakdown and holds the peak at 207 V maximum while shunting 7.2 A of surge current. For a 12 V automotive battery line, that 128 V standoff looks high, but this part is sized for 48 V or 72 V bus rails where transients can exceed 150 V. The DO-214AB (SMC) package handles the thermal pulse — the large copper tab on the bottom side conducts heat into the PCB pad, so the board layout's copper area directly sets the derating. Surface-mount assembly means reflow profile matters; the -65°C to 150°C junction range covers under-hood automotive ambient.
Automotive qualification and sourcing posture
The TransZorb® trademark is Vishay's branded TVS technology; the 'HE3' suffix in the order code flags the AEC-Q101 variant.