Four-channel rail-to-rail ESD clamp for Ethernet ports
The Texas Instruments TPD4E001DRLR is a four-channel steering (rail-to-rail) TVS diode array designed to protect sensitive ICs on high-speed data lines. Peak pulse power is rated at 100W, enough for the IEC 61000-4-2 ESD strikes typical on Ethernet ports and other differential signal interfaces. The part comes in a SOT-5X3 package (also listed as SOT-563 or SOT-666), a small footprint that fits tight layout budgets on multi-port switch designs.
The 100W peak pulse power rating (8/20 µs waveform) tells you the device can absorb a single ESD event up to that energy without failing. For 10/100Base-T Ethernet, the four channels map directly to the two differential pairs (TX+/TX−, RX+/RX−), with the steering diodes shunting the transient to the supply or ground. The 5.5V standoff sits comfortably above the 3.3V or 2.5V supply rails used by most PHYs, so the diode stays off during normal signalling. Below 11V breakdown the part does not conduct, preserving signal integrity. This is a steering array, not a standard TVS — it relies on an external rail capacitor to absorb the energy, so the decoupling cap on the protected supply rail needs to be sized for the transient charge.
Active lifecycle — no LTB worry
The base product number TPD4E001 covers several package variants; the DRLR suffix denotes the SOT-5X3 reel.