What the 1500W rating means for your rail protection
The STMicroelectronics 1.5KE220CA is a bidirectional transient voltage suppressor from the 1.5KE TRANSIL™ series, rated for 1500W peak pulse power over a 10/1000µs waveform. It clamps at 388V maximum from a 188V reverse standoff voltage, making it a fit for protecting 188V DC rails or AC lines in general-purpose industrial and telecom equipment. The 26A peak pulse current rating (8/20µs) gives a realistic surge-handling number for IEC 61000-4-5 coordination.
Package and mounting — through-hole axial DO-201
Housed in a DO-201AA / DO-27 axial-lead through-hole package, the 1.5KE220CA suits point-to-point wiring or PCB mounting with drilled holes. The axial leads handle the thermal cycling of high-energy pulses better than surface-mount alternatives in some layouts, though the board real estate is larger than an SMC package.
Capacitance and signal integrity
With 312.5pF capacitance at 1MHz, this part loads high-speed data lines noticeably — it is better suited for power rails and low-frequency signal protection than for gigabit Ethernet or USB 3.x. For high-speed interfaces, a lower-capacitance TVS (e.g., the 1.5KE series' own lower-voltage siblings or a dedicated data-line protector) would be the pick.