1.5 kW transient suppressor for 102 V rails
The STMicroelectronics 1.5KE120A is a unidirectional transient voltage suppression (TVS) diode from the 1.5KE series, also branded as TRANSIL™. The device is rated for a reverse standoff voltage of 102 V, with a minimum breakdown voltage of 114 V and a maximum clamping voltage of 212 V at the peak pulse current of 47 A (8/20 µs waveform).
Clamping voltage and standoff — selecting the right rail
The 114 V minimum breakdown voltage (VBR) is where the device starts to avalanche, and the 212 V maximum clamping voltage (VC) is the peak voltage the protected circuit sees during a 47 A surge (8/20 µs). The gap between VRWM and VC is the clamping headroom: a 102 V rail sees the clamp engage at roughly 114 V and hold the transient to 212 V, which is safe for downstream devices rated for 250 V or higher. For a 1500 W pulse, the 47 A peak current rating confirms the diode can absorb the energy without exceeding its thermal limit.
Through-hole DO-201 — board-level mounting
The 1.5KE120A is supplied in a DO-201AA (DO-27) axial-lead package, a through-hole footprint that suits wave-solder assembly or hand-soldering for prototyping and rework. The DO-201 body is rated for the 1500 W pulse without derating at 25 °C lead temperature; derating is linear above that per the datasheet curve. The axial leads allow in-line or vertical mounting on a PCB, and the package is compatible with standard 0.100-inch pitch holes.
The part is available in cut tape (CT) and tape-and-box (TB) packaging options, which suit both prototype quantities and production reel requirements.