The STMicroelectronics ESDA6V1P6 is a 4-channel unidirectional Zener transient-voltage-suppression array in the ESDA TRANSIL™ family, housed in a SOT-666 package. It provides 150 W peak pulse power per IEC 61000-4-5 with a minimum breakdown voltage of 6.1 V and a reverse standoff of 3 V.
150 W peak pulse — sizing the protection for the bus
The 150 W peak pulse power at 8/20 µs waveform means each of the four channels can clamp a 24 A (8/20 µs) transient to a safe voltage before the 6.1 V breakdown triggers. For a 3 V signal line — typical for 3.3 V logic or low-voltage data interfaces — the reverse standoff of 3 V leaves margin below the breakdown knee, so the device stays transparent during normal operation and only clamps during an overvoltage event. No power-line protection means this part is intended for signal-line ESD and surge clamping, not for bulk supply rails.