Alpha & Omega Semiconductor Inc. AOZ8S305BLS-04

Overview

AOZ8S305BLS-04 from Alpha & Omega Semiconductor is a single-channel bidirectional TVS diode designed for ESD and transient protection of high-speed data lines including USB 2.0/3.2, Thunderbolt, and PCIe. It features ±30 kV IEC 61000-4-2 contact/air ESD immunity, 0.5 pF junction capacitance, 4 V reverse working voltage, and 5.3 V clamping voltage at 20 A surge current.

For engineers reviewing the AOZ8S305BLS-04 datasheet, pinout, applications, or equivalent options, key selection criteria include low-capacitance signal-line protection, bidirectional clamping capability, WLCSP 0.6×0.3 mm package constraints, and compliance with IEC 61000-4-2/4-4/4-5 standards for mobile and portable interface designs.

Technical Context

The AOZ8S305BLS-04 implements a symmetric bidirectional TVS structure optimized for differential high-speed signaling paths. Its ultra-low 0.5 pF capacitance ensures minimal signal integrity degradation up to 16 Gbps (Thunderbolt 3.0), while maintaining sub-5.3 V clamping at full 20 A IEC 61000-4-5 surge current.

It operates across –40°C to +125°C ambient, supports any-pin-to-any-pin transient suppression between I/O lines, and uses a silicon-based avalanche junction with dynamic resistance of 0.1 Ω (1–16 A TLP range) to deliver fast response and stable clamping performance under repetitive ESD events.

Key Specifications

Pinout & Package

AOZ8S305BLS-04 is housed in a RoHS-compliant WLCSP (Wafer-Level Chip-Scale Package) measuring 0.6 mm × 0.3 mm with 2 terminals. The package uses solder bumps directly on the silicon die, enabling minimal parasitic inductance for high-frequency transient suppression.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ4.0A and TPD4E001DRYR, the AOZ8S305BLS-04 uniquely combines 0.6 × 0.3 mm size, true bidirectionality, and 0.5 pF capacitance-making it the only option suitable for single-lane, ultra-compact, high-speed differential interface protection without compromising signal fidelity.

Availability

AOZ8S305BLS-04 is available at Aetrix Electronics and suitable for USB 3.2, Thunderbolt 3.0, and PCIe Gen4 interface designs requiring stable component supply, consistent WLCSP packaging, and guaranteed ESD immunity performance across production batches.

Supply support for AOZ8S305BLS-04 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 high-efficiency, high-density power and protection solutions.

The AOZ8S305BLS-04 belongs to AOS's ultra-low-capacitance TVS portfolio targeting high-speed digital interface protection, engineered specifically for space-constrained mobile and computing platforms demanding IEC-compliant ESD robustness without signal degradation.

FAQ

What is the clamping voltage of AOZ8S305BLS-04 at 20 A surge current?

The AOZ8S305BLS-04 has a clamping voltage of 5.3 V under IEC 61000-4-5 8/20 µs surge conditions at 20 A peak pulse current. This value is measured across the device terminals and ensures protected ICs remain within safe operating voltage limits during lightning-surge events. The low clamping level is enabled by its 0.1 Ω dynamic resistance and symmetric avalanche structure.

Is AOZ8S305BLS-04 unidirectional or bidirectional?

AOZ8S305BLS-04 is a bidirectional TVS diode, meaning it provides symmetrical clamping for both positive and negative transients without polarity sensitivity. This allows direct placement across differential signal pairs such as USB D+/D− or PCIe TX+/TX− without orientation concerns-confirmed in the datasheet's "Any Pin to Pin" specification and bidirectional electrical characteristics table.

What package type does AOZ8S305BLS-04 use, and what are its dimensions?

AOZ8S305BLS-04 uses a WLCSP (Wafer-Level Chip-Scale Package) with dimensions of 0.6 mm × 0.3 mm and a 2-terminal configuration. The package is lead-free, RoHS compliant, and features solder bumps directly on the silicon die-enabling minimal parasitic inductance and optimal high-frequency transient response. This footprint is documented in the official AOS ordering information table.

Does AOZ8S305BLS-04 meet IEC 61000-4-2 Level 4 ESD requirements?

Yes, AOZ8S305BLS-04 exceeds IEC 61000-4-2 Level 4 with ±30 kV contact discharge and ±30 kV air discharge ratings. These values are explicitly specified in the Absolute Maximum Ratings table and verified per IEC test conditions (150 pF/330 Ω). This makes AOZ8S305BLS-04 suitable for end-product certification in consumer, industrial, and automotive infotainment applications requiring highest ESD immunity.

Can AOZ8S305BLS-04 be used to protect 10 Gbps USB 3.2 Gen2 signals?

Yes, AOZ8S305BLS-04 is validated for USB 3.2 Gen2 (10 Gbps) signal integrity, as confirmed by published eye diagram and S21 insertion loss data in the datasheet. Its 0.5 pF junction capacitance results in <1 dB loss up to 10 GHz, preserving signal rise/fall times and eye opening. Placement directly at the connector-enabled by its 0.6 × 0.3 mm WLCSP-is critical to maintain this performance.