73.7 V standoff, 131 V clamp — the protection window
The 1.5KE91CHE3/73 is a 1500 W peak-pulse TVS diode from Vishay's TransZorb series, qualified to AEC-Q101 for automotive use. Its 73.7 V reverse standoff voltage means a 48 V or 60 V nominal rail stays below the leakage threshold, while the 131 V maximum clamp at 11.5 A peak pulse (10/1000 µs) limits the transient voltage the downstream silicon sees.
AEC-Q101 and the 175 °C junction
The bidirectional channel (one device protects both polarities) suits AC-coupled signal lines or power rails where the transient can swing positive or negative relative to ground.
Obsolete — sourcing through independent channels
Vishay has marked the 1.5KE91CHE3/73 as obsolete. Available through independent surplus and excess-stock channels. Quantities are lot-specific; availability and pricing are confirmed at RFQ against the BOM line.