1500W bidirectional TVS for high-voltage rail clamping
The 1.5KE350C: Its 300V reverse standoff voltage and 506.1V clamping ceiling make it a fit for protecting 300V DC bus rails or AC line rectified stages against transients up to 3.2A peak pulse current.
Obsolete — sourcing via surplus and broker channels
Littelfuse lists the 1.5KE350C as Obsolete. For BOM lines that still call out this part number, the primary channel is independent surplus and broker inventory. Availability is lot-specific — date-code spread and original packaging (sealed reel vs loose tube) vary by lot.
Parametric fit — what the ratings mean for your rail
The 300V reverse standoff (working voltage) means the diode draws negligible leakage below 300V DC — it stays out of the circuit during normal operation. The breakdown window starts at 315V minimum, so a 300V rail that sags to 310V during brownout still sees no clamping action. Clamping at 506.1V maximum under 3.2A peak pulse defines the voltage the downstream components must survive. If the protected device's abs-max rating is below 506V, a secondary clamp or a higher-power TVS (e.g., 5KP series) may be needed. The 1500W rating is derated above 25°C per the datasheet curve; at 125°C ambient the effective peak pulse power drops to roughly 750W.