Clamping voltage and pulse current — the real protection envelope
The 1.5KE150CAHB0G: The 207V maximum clamping voltage (at Ipp=7.6A) defines the voltage the downstream circuitry must survive. A 128V rail clamped to 207V leaves a 79V margin above nominal — tight enough that the protected device's abs-max rating should be checked against this ceiling. The 7.6A peak pulse current is the current the diode shunts during the 10/1000µs surge; the 1500W rating is the product of clamp voltage and pulse current at that waveform. The minimum breakdown voltage is 143V, ensuring the diode starts conducting before the rail exceeds the 128V standoff. The 175°C maximum junction temperature allows placement near hot components — an alternator or engine-bay ECU — without derating the pulse capability below the 1500W headline figure.
Through-hole DO-201 — board-fit and handling
The DO-201AA (DO-27) axial-lead package suits through-hole assembly and hand-solder rework. The 0.052-inch lead diameter fits standard 1.0mm PCB holes; the body length is about 9.1mm. For high-reliability automotive builds, the leads should be formed with a minimum bend radius of 1.5mm to avoid cracking the glass passivation at the lead exit.