Clamping voltage and the protection window
The 1.5KE170A-E3/54: This is the voltage the downstream circuitry sees during a transient event; the gap between the normal operating rail (145 V) and the clamp (234 V) is the protection window. A narrower window means less stress on the protected silicon, but the trade-off is higher standby leakage at the upper end of the operating range.
Breakdown tolerance and temperature range
Minimum breakdown voltage (V_BR) is 162 V at 1 mA test current. The actual breakdown voltage shifts with junction temperature — the datasheet's temperature coefficient for Zener-type TVS diodes is typically positive, so at 175 °C the V_BR rises by roughly 10–12 V from the 25 °C value. The operating junction temperature range spans -55 °C to 175 °C, covering the full industrial and automotive under-hood thermal envelope.
Package and board integration
Housed in the DO-201AA (DO-27) axial-lead package, the 1.5KE170A-/54 is a through-hole device. The body diameter and lead spacing match the standard 0.375-inch (9.5 mm) lead-to-lead footprint used across the TransZorb® family. For high-reliability builds, the leads should be formed with a minimum bend radius of 1.5 mm from the glass seal to avoid cracking the package body.