Alpha & Omega Semiconductor Inc. AOZ8304ADI

Overview

AOZ8304ADI from Alpha & Omega Semiconductor is a low-capacitance, 3.3 V transient voltage suppressor (TVS) array designed to protect four high-speed data lines from ESD and lightning surges. It features ±30 kV IEC 61000-4-2 contact/air discharge rating, 1.25 pF typical junction capacitance per I/O-to-GND, 7.0 V clamping voltage at 5 A, and operates over –40 °C to +85 °C in a DFN-10 2.6 mm × 2.6 mm package - ideal for USB 2.0 and Gigabit Ethernet port protection.

For engineers reviewing the AOZ8304ADI datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage under 10 A surge, sub-2 pF I/O-to-GND capacitance, compatibility with 3.3 V logic interfaces, and validated IEC 61000-4-2 Level 4 and IEC 61000-4-5 (25 A) compliance.

Technical Context

The AOZ8304ADI integrates eight steering diodes and one TVS element in a single DFN-10 package to route transients from four bidirectional I/O lines either to VP (pin 5, biased at 3.3 V) or GND. Its architecture enables low-inductance clamping with minimal signal distortion on high-speed lines.

Each protected channel exhibits 1.25 pF (typ.) junction capacitance at 0 V and 1 MHz, ≤7.0 V positive clamping at 5 A (100 ns pulse), and ≤–3.0 V negative clamping under identical conditions - ensuring integrity of signals up to 1 GHz as confirmed by S21 insertion loss measurements.

Key Specifications

Pinout & Package

AOZ8304ADI uses a halogen-free, RoHS-compliant DFN-10 package (2.6 mm × 2.6 mm, 0.55 mm height) with exposed center thermal pad connected to GND. The package supports both lead-free and SnPb reflow processes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TVS array applications.

Compared with SMA6J33A-Q and SP1006-04UTG, the AOZ8304ADI uniquely delivers quad-channel 3.3 V protection with ±30 kV ESD rating, 25 A lightning surge capability, and 1.25 pF capacitance - enabling single-device compliance with IEC 61000-4-2 Level 4 and IEC 61000-4-5 in space-constrained high-speed interfaces.

Availability

AOZ8304ADI is available at Aetrix Electronics and suitable for 10/100/1000 Ethernet port hardening, USB 2.0 interface protection, and DVI video link safeguarding requiring stable component supply across industrial, telecom, and computing applications.

Supply support for AOZ8304ADI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Alpha & Omega Semiconductor (AOS) is a fabless power semiconductor company specializing in MOSFETs, TVS diodes, and power ICs for efficiency-critical applications.

The AOZ8304ADI belongs to AOS's low-capacitance TVS array product line, engineered specifically for ESD and surge protection of high-speed digital interfaces operating at 3.3 V logic levels.

FAQ

What is the recommended bias voltage for VP (pin 5) on the AOZ8304ADI?

The AOZ8304ADI requires VP (pin 5) to be externally biased at 3.3 V to enable correct steering diode operation during transient events. This bias establishes the reference for clamping positive transients to VP and negative transients to GND. Applying 3.3 V ensures the AOZ8304ADI maintains its specified 7.0 V clamping voltage at 5 A and meets IEC 61000-4-2 Level 4 requirements. Do not leave VP floating or tie it directly to GND or VCC >3.3 V.

Can the AOZ8304ADI protect more than four I/O lines simultaneously?

No - the AOZ8304ADI is designed exclusively to protect four I/O lines (pins 1, 3, 7, 9), each corresponding to one channel (CH1–CH4). Pins 2, 4, 6, 8, and 10 are NC and must remain unconnected. Attempting to route additional signals through NC pins violates the device's internal layout and compromises ESD performance. For more than four lines, multiple AOZ8304ADI units or a higher-channel-count array like AOZ8310ADI (8-channel) should be used.

Does the AOZ8304ADI require external capacitors on VP or I/O pins?

No external capacitors are required or recommended on VP (pin 5) or any I/O pins of the AOZ8304ADI. Electrical characteristics including VCL and Cj are measured with VP floating (per datasheet note 6) or biased at 3.3 V (note 7), and with no external capacitance. Adding capacitors introduces parasitic impedance that degrades clamping speed and may cause resonance with the device's low inductance, increasing overshoot. Layout best practice is direct routing from connector to AOZ8304ADI with minimal trace length.

How does the AOZ8304ADI achieve ±30 kV ESD protection with only 1.25 pF capacitance?

The AOZ8304ADI achieves ±30 kV ESD protection without sacrificing bandwidth by combining ultra-low-junction-capacitance steering diodes (1.25 pF I/O-to-GND) with a low-inductance DFN-10 package and integrated TVS structure. Its internal architecture routes transients through short, symmetric paths to VP or GND, minimizing parasitic inductance that would otherwise cause voltage overshoot. This allows the AOZ8304ADI to clamp fast-rising ESD pulses (tR < 1 ns) while maintaining signal fidelity up to 1 GHz - verified by S21 insertion loss and crosstalk plots in the datasheet.

Is the center thermal pad of the AOZ8304ADI electrically connected to GND?

Yes - the exposed center thermal pad on the AOZ8304ADI is internally connected to GND and must be soldered to a dedicated PCB ground plane. This connection serves dual purposes: it provides a low-inductance return path for surge current during ESD or lightning events, and enhances thermal dissipation during repetitive transient absorption. Failure to connect the pad to GND degrades clamping performance and risks exceeding junction temperature limits under sustained surge conditions.