What the 1500 W rating means for your board
The 1.5KE33AG: The reverse standoff voltage is 28.2 V, meaning the diode stays off below that level and only starts conducting when the transient exceeds it. Breakdown occurs at a minimum of 31.4 V, so there is a 3.2 V window between normal rail operation and the onset of clamping — enough headroom for a 24 V bus with tolerance.
Through-hole axial package — still a breadboard-friendly choice
Housed in a DO-201AD axial-leaded package, the 1.5KE33AG is a through-hole part. The two axial leads solder into plated through-holes on the board — no reflow profile, no paste stencil, just a soldering iron and a clean joint. For a hobbyist or a repair tech swapping a blown suppressor on a power supply, this is the easiest package to work with: you can hand-solder it in under a minute. The operating temperature range spans -65°C to 175°C (junction), which covers everything from outdoor telecom cabinets to engine-bay electronics. The wide range also means the leakage current at high temperature stays within the datasheet limits — a concern for low-power circuits where a few microamps of standby leakage matter.
Obsolete — sourcing reality for the 1.5KE33AG
Littelfuse has marked the 1.5KE33AG as Obsolete. That means the manufacturer no longer produces it, and no official successor order code is listed. Because the part is a single unidirectional Zener TVS in a standard DO-201AD package, functionally equivalent alternatives exist from other brands (e.g., similar 1500 W, 28 V standoff parts in the same footprint). If you are sourcing for a repair or a legacy design, we can quote the 1.5KE33AG against your BOM quantity.