Clamping performance and standoff window
The 1.5SMC9.1A-E3/57T: With a 7.78 V reverse standoff and an 8.65 V minimum breakdown, the diode sits below the 9.1 V nominal Zener voltage until a surge arrives — the standoff rating sets the DC operating voltage the protected rail can carry continuously without conduction.
Junction thermal range and field deployment
DO-214AB (SMC) is a standard surface-mount outline — the cathode band is marked on the body, which is usually enough to get orientation right without checking polarity with a multimeter first.
Package and pick-and-place handling
Offered in Tape & Reel and Cut Tape — the reel suits high-volume pick-and-place; cut tape is useful for prototype runs or repair work where you are pulling a handful from a reel.
Sourcing posture and lifecycle
The part is listed Active — no last-time-buy window or successor order code appears in the record.