1500W transient suppressor for 400V-class DC rails
The Comchip Technology 1.5KE400A-G is a 1500W peak pulse power Zener TVS diode in a through-hole DO-201AA/DO-27 axial package. Its 342V reverse standoff voltage and 380V minimum breakdown voltage place it squarely on a nominal 400V DC bus or 277VAC rectified rail, where it clamps transients to 548V maximum at the rated 2.72A peak pulse current (10/1000µs waveform). The unidirectional channel (single device) and 1500W power rating make it a standard choice for DC power supply input protection, industrial equipment surge suppression, and communication line secondary-side clamping where a single-polarity clamp is sufficient.
Clamping voltage and surge current — the real protection envelope
At 548V maximum clamping, the 1.5KE400A-G holds the let-through voltage below 550V on a 400V bus — this margin protects downstream semiconductors rated for 600V or higher. The 2.72A peak pulse current at the 10/1000µs test waveform confirms the device can absorb a standard telecom surge without exceeding its thermal limit. The -55°C to 150°C junction temperature range covers the full industrial operating band and extends into underhood automotive environments. At the high end, derating of the peak pulse power applies per the datasheet derating curve — a 150°C junction with no derating at 25°C drops to roughly 60% at 125°C, so the effective surge capability at elevated temperature should be factored into the worst-case thermal analysis. No power line protection means this device is intended for signal or secondary-side DC rail clamping, not for mains AC primary-side surge suppression where coordinated MOV and GDT circuits are required.
Through-hole DO-201 axial — board integration and availability
The DO-201AA/DO-27 axial package is a standard through-hole form factor with 0.052-inch (1.3mm) lead diameter, compatible with existing wave-solder and hand-solder assembly lines. The axial leads allow vertical or horizontal mounting depending on board clearance — a common layout for high-reliability power supplies and industrial control boards where the TVS sits close to the input connector.