6 Detailed Description

6.1 Overview

The ESD321 is a low capacitance uni-directional ESD Protection Diode with a low clamping voltage. This device

can dissipate ESD strikes up to ±30kV (Contact and Air) per the IEC 61000-4-2 Standard. The low clamping

makes this device suitable for protecting any ESD sensitive devices.

6.2 Functional Block Diagram

6.3 Feature Description

ESD321 provides ESD protection up to ±30kV contact and ±30kV air gap per IEC 61000-4-2 standard. During

an ESD event, ESD diode connected to the I/O pin turns on and diverts the current to ground. Additionally,

ESD321 also provides protection against IEC 61000-4-5 Surge currents up to 6A (8/20µs waveform) and up to

80A per IEC 61000-4-4 (5/50ns waveform, 4kV with 50Ω impedance) electrical fast transient (EFT) standard.

The capacitance between the I/O pin and ground is 0.9pF (typical) and 1.1pF (maximum). The device features

a low leakage current of 0.1nA (typical) and 50nA (maximum, across operating temperature range) with a bias

of 3.6V. The ESD diode at the I/O pin protects the ESD-sensitive devices by clamping the voltage to a low value

of 6.8V (IPP = 16A 100ns TLP ). The layout makes adding protection to an existing layout simple. The package

offers flow-through routing, requiring minimal modification to an existing layout.

6.4 Device Functional Modes

The ESD321 is a passive integrated circuit that triggers when voltages exceed VBRF or fall below VFWD. During

ESD events, voltages as high as ±30kV (contact or air) can be directed to ground through the internal diode

network. When the voltages on the protected line fall below the trigger levels of ESD321 (typically within 10ns)

the device returns to passive.

ESD321

SLVSEN8C – JULY 2018 – REVISED JUNE 2025

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