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Alpha & Omega Semiconductor Inc. AOZ8251BDI-12
- Part No.:
- AOZ8251BDI-12
- Manufacturer:
- Alpha & Omega Semiconductor Inc.
- Category:
- TVS Diodes
- Package:
- 0201 (0603 Metric)
- Datasheet:
-
AOZ8251BDI-12.pdf
- Description:
- 1 CHANNEL 12V BIDIRECTIONAL TVS
- Quantity:
- Payment:
- Shipping:
Inventory:3,330
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Product details
Overview
AOZ8251BDI-12 from Alpha & Omega Semiconductor is a one-line bi-directional TVS diode designed for ESD and transient protection of single I/O signal lines in portable electronics. It features a 12 V reverse working voltage (VRWM), ±20 kV IEC 61000-4-2 contact/air ESD rating, 1.5 A IEC 61000-4-5 lightning surge capability, 4.5–6.5 pF junction capacitance, and operates from –40°C to +125°C ambient.
For engineers reviewing the AOZ8251BDI-12 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage at 1.5 A (25 V max), dynamic resistance (0.3 Ω), low leakage (<100 nA at 12 V), DFN 1.0 mm × 0.6 mm footprint, and suitability for high-speed data line protection where space and signal integrity are critical.
Technical Context
The AOZ8251BDI-12 implements a symmetric bi-directional avalanche structure optimized for fast response to ±ESD transients and 8/20 µs surges. Its design targets low clamping voltage under 1.5 A surge current (25 V max) and minimal capacitive loading (4.5–6.5 pF) on protected lines.
It operates as a two-terminal device with no polarity requirement, enabling direct placement between I/O and ground. The ultra-small DFN package supports automated assembly and maintains thermal performance across –40°C to +125°C ambient, meeting industrial and portable operating requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 12 V - Maximum continuous DC voltage the device blocks without conduction |
| VBR (min) | 13 V - Reverse breakdown initiates reliably above this threshold during transients |
| VCL @ IPP=1.5A | 25 V max - Peak voltage seen by protected circuit during 8/20 µs surge event |
| CJ | 4.5–6.5 pF - Low capacitance preserves signal integrity on high-speed lines (e.g., USB, I²C) |
| ESD Rating | ±20 kV air / ±20 kV contact - Meets IEC 61000-4-2 Level 4 immunity requirements |
| RDYN | 0.3 Ω - Low dynamic resistance ensures efficient energy shunting during fast transients |
| Operating Temp | –40°C to +125°C - Supports industrial-grade reliability in compact portable enclosures |
Pinout & Package
AOZ8251BDI-12 uses a RoHS-compliant, lead-free DFN package measuring 1.0 mm × 0.6 mm × 0.5 mm (0.62 mm × 0.32 mm body). This ultra-compact two-terminal surface-mount device has no polarity marking and is mounted directly across the protected signal line and ground.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 | I/O Signal Line Anode/Cathode | Bi-directional terminal - connects to protected signal line (e.g., USB D+, I²C SDA) |
| Terminal 2 | GND Reference | Connects directly to system ground plane; forms low-inductance path for transient current |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 ESD Protection | ±20 kV contact/air - exceeds Level 4, eliminating need for external ESD staging in handheld designs |
| Low Junction Capacitance | 4.5–6.5 pF - enables use on 100+ Mbps interfaces without signal degradation |
| Fast Clamping Response | Sub-nanosecond turn-on - suppresses ESD events before IC input structures are damaged |
| Ultra-Small DFN Footprint | 0.62 mm × 0.32 mm - saves >70% board area vs. SOD-323, critical for thin mobile PCBs |
| High Surge Robustness | 1.5 A (8/20 µs) per IEC 61000-4-5 - protects against induced lightning surges in unshielded cables |
Applications
| USB 2.0 Data Lines | Smartphone Keypad Interfaces |
|---|---|
Use Scenario: Protecting D+ and D− lines in smartphone USB ports from repeated plug/unplug ESD events. IC Role / Device Role / Timing Role: Bi-directional transient voltage suppressor placed between each data line and chassis ground. Use Value: Maintains 480 Mbps signaling integrity while clamping ±20 kV ESD strikes to ≤25 V peak at 1.5 A surge. | Use Scenario: Shielding mechanical keypad matrix lines in ruggedized handheld devices from user-contact ESD. IC Role / Device Role / Timing Role: Two-terminal TVS connected across each row/column trace and ground plane. Use Value: Prevents false keypresses and microcontroller reset due to ±20 kV contact discharge without adding series impedance. |
| Industrial Sensor I/O | Portable GPS RF Front-End |
Use Scenario: Safeguarding analog/digital sensor outputs (e.g., I²C, UART) in factory-floor equipment exposed to maintenance ESD. IC Role / Device Role / Timing Role: Single-line TVS on each bidirectional signal path, minimizing parasitic capacitance. Use Value: Enables operation up to +125°C ambient while delivering <100 nA leakage at 12 V VRWM for stable sensor biasing. | Use Scenario: Protecting GPS antenna feedline control signals (e.g., LNA enable, band-switch) from static discharge during field handling. IC Role / Device Role / Timing Role: Low-capacitance TVS on digital control lines adjacent to RF section, avoiding detuning. Use Value: 4.5–6.5 pF capacitance prevents shift in GPS L1 band matching networks; 12 V VRWM matches typical control rail. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bi-directional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12CA | DO-214AC package (4.5 mm × 2.7 mm); 12 V VRWM; 23.2 V VCL @ 1.5 A; 19 pF CJ | Higher capacitance and larger footprint limit use on >10 Mbps lines and space-constrained PCBs | Preferred when higher surge rating (23.5 A) is required and board area permits |
| TPD2E001DRYR | DFN 1.0 mm × 0.6 mm; dual-channel; 5 V VRWM; 12 V VCL @ 1 A; 3.5 pF CJ | Lower VRWM and dual-line configuration suit 3.3 V I/O only; not rated for 12 V systems | Select for 3.3 V high-speed interfaces requiring sub-4 pF loading, not for 12 V signal rails |
Compared with SMAJ12CA and TPD2E001DRYR, the AOZ8251BDI-12 uniquely balances 12 V working voltage, 1.5 A surge capability, ultra-low 4.5–6.5 pF capacitance, and 1.0 mm × 0.6 mm DFN size-making it optimal for space-limited 12 V I/O protection where signal fidelity and ESD robustness are both critical.
Availability
AOZ8251BDI-12 is available at Aetrix Electronics and suitable for portable hand-held devices, industrial sensor I/O, and GPS control line protection requiring stable component supply, long-term lifecycle support, and consistent RoHS/Green compliance.
Supply support for AOZ8251BDI-12 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 high-efficiency MOSFETs, TVS diodes, and power ICs for consumer, computing, and industrial markets.
The AOZ8251BDI family was developed to deliver ultra-compact, high-reliability ESD protection for next-generation portable electronics with stringent board space and signal integrity constraints.
FAQ
What is the maximum clamping voltage of AOZ8251BDI-12 under IEC 61000-4-5 surge conditions?
The AOZ8251BDI-12 has a maximum clamping voltage of 25 V when subjected to a 1.5 A, 8/20 µs surge per IEC 61000-4-5. This value is measured across the device terminals with specified test conditions and ensures downstream circuitry remains within safe operating limits during lightning-induced transients. The AOZ8251BDI-12 achieves this performance while maintaining low dynamic resistance (0.3 Ω) and minimal parasitic capacitance.
Does AOZ8251BDI-12 support bidirectional signal lines like USB or I²C?
Yes, AOZ8251BDI-12 is inherently bidirectional and requires no polarity orientation during placement. Its symmetrical avalanche structure provides identical clamping behavior for positive and negative transients, making it suitable for protecting full-duplex or open-drain interfaces such as USB 2.0 D+/D−, I²C SDA/SCL, and UART TX/RX lines. The AOZ8251BDI-12's 4.5–6.5 pF capacitance avoids signal rise-time degradation on these buses.
What is the junction capacitance range of AOZ8251BDI-12 and how does it affect high-speed signals?
The AOZ8251BDI-12 exhibits a junction capacitance of 4.5–6.5 pF at 0 V bias and 1 MHz, verified per datasheet testing. This low, tightly controlled capacitance minimizes loading on high-speed signal paths-enabling reliable operation on interfaces up to 480 Mbps (USB 2.0) without measurable eye diagram closure or timing jitter. The AOZ8251BDI-12's capacitance remains stable across its operating voltage range, supporting consistent signal integrity.
Can AOZ8251BDI-12 replace AOZ8251BDI-05 in a 5 V system?
No, AOZ8251BDI-12 is not a drop-in replacement for AOZ8251BDI-05 in 5 V systems. Its 12 V reverse working voltage (VRWM) means it will not clamp transients below ~13 V, leaving 5 V logic nodes vulnerable to overvoltage. The AOZ8251BDI-05 has a 5 V VRWM and lower clamping voltage optimized for 5 V rails. Selecting AOZ8251BDI-12 in a 5 V design risks insufficient protection and potential IC damage during ESD events.
Is AOZ8251BDI-12 compliant with automotive AEC-Q200 or industrial standards?
The AOZ8251BDI-12 is not AEC-Q200 qualified. It is rated for industrial temperature operation (–40°C to +125°C) and meets IEC 61000-4-2 (ESD), IEC 61000-4-5 (surge), and HBM (±30 kV) standards. Its RoHS-compliant, green packaging and DFN construction support industrial and consumer applications-but AOZ8251BDI-12 is not certified for automotive use. For automotive designs, consult AOS' AEC-Q200-qualified TVS portfolio separately.
AOZ8251BDI-12 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Alpha & Omega Semiconductor Inc.
- Package/Case:
- 0201 (0603 Metric)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 12V (Max)
- Voltage - Breakdown (Min):
- 13V
- Voltage - Clamping (Max) @ Ipp:
- 25V
- Current - Peak Pulse (10/1000µs):
- 1.5A (8/20µs)
- Power - Peak Pulse:
- -
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 4.5pF @ 1MHz
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 2-DFN (0.62x0.32)
AOZ8251BDI-12 FAQ
1.How can I place an order for AOZ8251BDI-12 through Aetrix?
Please submit a Request for Quotation (RFQ) for AOZ8251BDI-12 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AOZ8251BDI-12 reliable?
The price and inventory of AOZ8251BDI-12 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AOZ8251BDI-12 is usually 5 days.
3.What payment methods are accepted for AOZ8251BDI-12?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AOZ8251BDI-12 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AOZ8251BDI-12?
AOZ8251BDI-12 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AOZ8251BDI-12 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AOZ8251BDI-12?
For technical support, including AOZ8251BDI-12 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AOZ8251BDI-12 requirements.
6.How does Aetrix verify that AOZ8251BDI-12 is sourced from the original manufacturer or authorized distributors?
All AOZ8251BDI-12 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AOZ8251BDI-12 meets industry standards.
7.What is the process for return or replacement of AOZ8251BDI-12?
All AOZ8251BDI-12 units undergo pre-shipment inspection (PSI). If there is an issue with AOZ8251BDI-12, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AOZ8251BDI-12 part is unused and in its original packaging.
Return procedure for AOZ8251BDI-12:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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