Four-channel Zener clamp for signal-line ESD
The Texas Instruments TPD4E002DRL2 is a four-channel Zener-type ESD protection array in a SOT-553 package. Each of the four unidirectional channels clamps transients above a 6.1V breakdown minimum, with a 3V reverse standoff for normal signal levels. The array is rated for 35W peak pulse power, enough for IEC 61000-4-2 level 4 contact ESD strikes on general-purpose I/O lines.
The 3V reverse standoff means the part clamps signals above 3V, so it is a natural fit for 3.3V logic families — think UART, SPI, or GPIO lines on a microcontroller. The 6.1V minimum breakdown gives a 3.1V window above the rail before the Zener conducts, which keeps leakage low during normal operation. No power-line protection here — the part is designed for signal lines only, so keep it off the power bus.
The base product number TPD4E002 covers the family; the DRL2 suffix specifies the SOT-553 tape-and-reel variant. RoHS compliance is standard for this TI series, so it passes the usual environmental restrictions for commercial and industrial builds.