1500 W pulse rating and the protection window for a 185 V rail
The 1.5KE220A-E3/54: For a 185 V nominal rail, the reverse standoff voltage (185 V) sits below the normal operating level so the diode stays off during steady state; the breakdown voltage (209 V min) defines the threshold where clamping begins, and the maximum clamp voltage (328 V at 4.6 A peak pulse current) limits the transient energy that reaches the downstream circuit. This is a single-channel, unidirectional device — the cathode band orients toward the positive rail, making it a fit for DC bus clamping in power supplies, industrial controls, and automotive electronics where the transient polarity is known.
Temperature range and pulse derating
The operating junction temperature range spans -55°C to 175°C. At elevated ambient temperatures the peak pulse power must be derated — the 1500 W rating is specified at 25°C; above that the allowable pulse power decreases linearly per the datasheet derating curve. For an enclosure that sees 85°C internal ambient, the effective pulse capability drops to roughly 60% of the 25°C figure.
Package and board integration
Housed in a DO-201AA (DO-27) axial-lead through-hole package, the device body is 1.5KE-series standard. The axial leads require a hole diameter of about 1.1 mm for the lead wire; the body length and diameter determine the keep-out zone for adjacent components. Through-hole construction gives a lower thermal resistance path to the board compared to an equivalent SMD package, which helps with repetitive pulse handling.