1500 W peak pulse, bidirectional, DO-201 axial — what the ratings mean for the BOM
The 1.5KE91CA-T is a 1500 W (1.5 kW) bidirectional Zener TVS diode from Diodes Incorporated, in a through-hole DO-201AA / DO-27 axial package. The 1500 W rating means this part absorbs a 1.5 kW surge for a standard 10/1000 µs pulse — enough for secondary protection on 48 V telecom rails or 60 Vdc bus lines where the steady-state voltage stays under 77.8 V. The bidirectional construction (one channel) lets it clamp both polarities, so it works on AC-coupled signal lines or DC rails without worrying about orientation.
Obsolete — sourcing through independent channels
Diodes Incorporated has marked the 1.5KE91CA-T as Obsolete.
Package and rework — DO-201 axial is a bench-friendly through-hole part
The DO-201AA / DO-27 axial package is a through-hole form factor with two wire leads — easy to hand-solder or wave-solder, and straightforward to remove with a desoldering station or hot-air preheat from the board side. The body is cylindrical, about 9 mm long, with a cathode band (though for a bidirectional part polarity marking is less critical). No pad lifting risk if the leads are cut flush after soldering. The wide bandgap of the Zener junction means leakage stays manageable at elevated temperatures compared to lower-voltage parts.