ePoly (Polymer ESD Suppressor)
ESD protection with about 0.05 pF of capacitance, for antenna, RF and very high-speed lines.
What is it?
ePoly is the Magnias family of ultra-low-capacitance polymer ESD suppressors. Like an ESD diode it sits between a signal line and ground, but its capacitance is only about 0.05 pF, so it barely loads even an antenna or a multi-gigabit line. In normal operation it stays off, with leakage below 10 nA. When an ESD pulse arrives, it turns on at its trigger voltage, clamps the line to about 40 V while it carries the discharge, and then returns to its off state. It is bidirectional.
When do you need it?
- Antenna and RF lines (cellular, GPS, Bluetooth, NFC) where a fraction of a picofarad would detune the match.
- Very high-speed lines such as HDMI, USB 3.x / USB4 and Thunderbolt.
- Phones, laptops, set-top boxes, TVs and game consoles.
- Tight boards: single lines in 0201, or four lines in one DFN2510-10L.
How to pick the right one
- VDC (continuous operating voltage)
- Must be at least the highest DC voltage on the line. Magnias parts run from 4 V to 40 V.
- Capacitance (CJ)
- About 0.05 pF typical (at 10 MHz) on every Magnias ePoly part, low enough for antenna and multi-gigabit lines.
- Trigger and clamping voltage (VT, VC)
- VT is the peak the line sees before the part turns on (300-450 V typical); VC is the level it then clamps to (about 40 V typical), both measured with an 8 kV contact discharge. Both are higher than for a silicon ESD diode, so pick ePoly where capacitance matters more than clamping voltage.
- ESD rating and endurance
- IEC 61000-4-2 ±8 kV contact and ±15 kV air, rated for 1,000 ESD pulses.
- Leakage
- Below 10 nA, so it does not load bias or sensor lines.
- Package and channels
- Single line in 0201, 0402 or 0603, or four lines in DFN2510-10L (PESD12G-Q10).
What Magnias offers
Magnias ePoly polymer ESD suppressors (PESD04G-Q2 up to PESD40G-Q4) cover VDC from 4 V to 40 V with about 0.05 pF, bidirectional, IEC 61000-4-2 ±8 kV contact / ±15 kV air, leakage below 10 nA and 1,000-pulse ESD endurance. Single-line parts come in 0201, 0402 and 0603; PESD12G-Q10 protects four lines in DFN2510-10L.