Automotive-grade TVS in a through-hole axial package
The 1.5KE170AHE3_A/D is a 1500 W unidirectional TVS diode from Vishay's TransZorb® series, qualified to AEC-Q101 for automotive use. The DO-201AA axial package (also known as DO-27) is a through-hole form factor that suits high-reliability board-level transient suppression in power distribution or ECU input protection. The operating temperature range spans -55 °C to 175 °C, covering under-hood and engine-bay thermal profiles.
What the clamping and standoff ratings mean for the BOM
A 145 V reverse standoff voltage means the diode does not conduct at normal operating levels up to that rail — it stays invisible to the circuit until a transient exceeds the breakdown threshold. The minimum breakdown voltage is 162 V, so the device starts clamping just above the normal DC bus. Maximum clamping at 234 V for a 6.4 A pulse means the downstream components see no more than 234 V during the surge event.