Alpha & Omega Semiconductor Inc. AOZ8S501BS2-05

Overview

AOZ8S501BS2-05 from Alpha and Omega Semiconductor is a 2-channel bidirectional transient voltage suppressor (TVS) designed for ESD and surge protection of high-speed data lines. It delivers ±30 kV IEC 61000-4-2 ESD immunity, 20 A IEC 61000-4-5 surge rating, 35 pF junction capacitance, 5 V reverse working voltage, and clamps to ≤9.5 V at 30 A TLP-ideal for audio line protection in mobile phones and notebook computers.

For engineers reviewing the AOZ8S501BS2-05 datasheet, pinout, applications, or equivalent options, key selection factors include bidirectional clamping capability, low capacitance for signal integrity, IEC-compliant surge/ESD ratings, thermal robustness to +125°C, and SOT23-3L footprint compatibility with space-constrained portable designs.

Technical Context

The AOZ8S501BS2-05 integrates two monolithic bidirectional TVS diodes in a single SOT23-3L package, enabling simultaneous protection of two independent I/O lines without polarity constraints. Its snapback behavior-evidenced by 5.5 V hold voltage and 5.7–9 V breakdown range-ensures stable clamping during fast transients while maintaining low leakage (<100 nA at 5 V).

It supports dual-mode transient suppression: 100 ns TLP pulses up to 30 A (clamping ≤9.5 V), and standardized 8/20 μs surge events at 20 A (clamping ≤11.5 V). Capacitance remains stable at 35 pF (measured at 1 MHz, 0 V bias), minimizing signal distortion on audio and USB-adjacent lines.

Key Specifications

Pinout & Package

SOT23-3L package: 3-pin surface-mount, RoHS-compliant and halogen-free, footprint compatible with standard SOT-23 pick-and-place equipment. Dimensions: 2.9 mm × 1.3 mm × 1.0 mm (L × W × H).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMAJ5.0A and TPD2E001DRYR, the AOZ8S501BS2-05 uniquely balances 35 pF capacitance, ±30 kV ESD, 20 A surge, and SOT23-3L simplicity-making it optimal for cost-sensitive, dual-line protection where moderate capacitance is acceptable and minimal board real estate is prioritized.

Availability

AOZ8S501BS2-05 is available at Aetrix Electronics and suitable for mobile phone audio protection, notebook peripheral interface hardening, and smart speaker microphone conditioning requiring stable component supply across production ramps.

Supply support for AOZ8S501BS2-05 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 and Omega Semiconductor (AOS) is a fabless power semiconductor company specializing in MOSFETs, TVS diodes, and power ICs for efficiency-critical applications.

The AOZ8S501BS2-05 belongs to AOS's Green TVS family-designed specifically for compact, high-reliability ESD/surge protection in portable consumer electronics with strict environmental compliance.

FAQ

What is the maximum clamping voltage of the AOZ8S501BS2-05 under IEC 61000-4-5 surge conditions?

The AOZ8S501BS2-05 clamps to ≤11.5 V at 20 A (8/20 μs surge waveform), per its Electrical Characteristics table. This value ensures downstream components experience limited overvoltage stress during lightning-induced or inductive-switching transients. The clamping performance is validated across temperature and process corners, and applies to both I/O1–Pin2 and I/O2–Pin2 paths in the AOZ8S501BS2-05.

Can the AOZ8S501BS2-05 protect both analog and digital signal lines?

Yes-the AOZ8S501BS2-05 is optimized for analog audio lines (e.g., headset jacks) and low-speed digital interfaces (e.g., I²C, GPIO, SBU) due to its 35 pF capacitance and bidirectional symmetry. It does not support high-speed protocols like USB 2.0 or HDMI, where sub-1 pF capacitance is required. For those, the AOZ8S501BS2-05 must be evaluated case-by-case based on trace length and data rate.

Is the AOZ8S501BS2-05 RoHS and halogen-free compliant?

Yes-the AOZ8S501BS2-05 meets RoHS Directive 2011/65/EU and is certified halogen-free per AOS Green Product standards. Its SOT23-3L package contains no brominated flame retardants, chlorine, or fluorine above threshold limits, and full compliance documentation is available in the AOS Green Policy PDF referenced in the datasheet.

How does the AOZ8S501BS2-05 achieve bidirectional protection with only three pins?

The AOZ8S501BS2-05 uses an internal center-tapped configuration: Pin 2 serves as the common reference node (connected to GND or VCC), while Pins 1 and 3 each form a symmetrical PN junction pair to that node-enabling clamping in both polarities without external components. This architecture is confirmed in the "Bidirection Protection of Two Lines" diagram on page 2 of the AOZ8S501BS2-05 datasheet.

What is the junction capacitance tolerance and measurement condition for the AOZ8S501BS2-05?

The AOZ8S501BS2-05 specifies 35 pF typical junction capacitance, measured at 1 MHz and 0 V DC bias across any I/O pin pair (e.g., Pin1–Pin2 or Pin2–Pin3), per the Electrical Characteristics table on page 3. No min/max range is specified-only typical value-indicating design-centered characterization rather than 100% test screening. This value holds across −40°C to +85°C ambient per typical curves.