ESD clamp for 5V signal lines
The ESD9X5.0ST5G is a single-channel Zener ESD protection diode from onsemi, housed in a SOD-923 package. It clamps transients on a 5V nominal rail, with a reverse standoff of 5V (max) and a breakdown minimum of 6.2V. The 12.3V clamping voltage at 8.7A (8/20µs pulse) keeps the protected IC within its absolute-maximum ratings during an ESD event.
65pF capacitance and signal integrity
At 65pF measured at 1MHz, this diode adds minimal capacitive loading to the signal line. That capacitance is low enough for USB 2.0 (480 Mbps), 100 Mbps Ethernet, and HDMI 1.4 — the added edge-rate degradation stays under 0.1 UI for most driver/receiver pairs. For sub-1 Gbps differential pairs, the 65pF per line is acceptable; above that, a sub-1pF TVS would be a better fit.
107W peak pulse capability
Rated for 107W peak pulse power (8/20µs waveform), the diode absorbs the energy from a standard IEC 61000-4-2 ESD strike at ±8 kV contact / ±15 kV air without damage. The 8.7A peak pulse current rating confirms the clamp can handle the full discharge current of a typical ESD gun. Power line protection is not supported — this is a signal-line-only device.
The SOD-923 package is a 0.60 mm × 0.30 mm footprint with 0.50 mm pitch; it reflows on a standard lead-free profile and shares a common land pattern with other SOD-923 ESD diodes.