Obsolete — sourcing the 1.5KE440-E3/54 today
The Vishay 1.5KE440-/54 is officially marked as Obsolete by the manufacturer, meaning Vishay no longer produces this TransZorb series TVS diode in the DO-201AA axial package. No official successor part number is recorded from Vishay for this specific order code. Sourcing relies on the independent surplus and broker channel, where lots are verified for date-code authenticity and traceability before quotation.
1500W peak pulse — what the ratings mean for fit
The reverse standoff voltage of 356V means the diode stays in high-impedance mode below that DC rail level — it only starts conducting when the transient exceeds the minimum breakdown threshold of 396V. With an operating junction temperature range from -55°C to 175°C, the 1.5KE440 holds its clamping spec across the full industrial and military temperature envelope — relevant for outdoor telecom rectifiers or 400V rail protection in motor drives.
Housed in a DO-201AA (DO-27) axial-leaded package, the 1.5KE440 is a through-hole component — the lead spacing and body diameter match the standard TVS footprint used across the TransZorb 1.5KE family. Tape and Reel (TR) packaging for this order code means the parts arrive on a reel suitable for automatic insertion equipment, not bulk or ammo pack.