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Taiwan Semiconductor Corporation SMAJ8.0H
- Part No.:
- SMAJ8.0H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ8.0H.pdf
- Description:
- 400W, 9.9V, UNIDIRECTIONAL, TVS
- Quantity:
- Payment:
- Shipping:
Inventory:5,509
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Product details
Overview
SMAJ8.0H from Taiwan Semiconductor is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode with a working stand-off voltage of 8 V, breakdown voltage range 8.89–10.90 V, and clamping voltage of 15.0 V at 50 A peak pulse current. It delivers fast sub-1 ps response time and <1 µA leakage above 10 V, designed for automotive-grade DC/DC converter input protection.
For engineers reviewing the SMAJ8.0H datasheet, SMAJ8.0H pinout, SMAJ8.0H application, or SMAJ8.0H equivalent, this device serves as a robust, AEC-Q101-qualified overvoltage clamp for 12 V rail systems requiring ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, low capacitance, and DO-214AC (SMA) board-level integration.
Technical Context
The SMAJ8.0H employs a glass-passivated silicon junction optimized for high-energy transient suppression under 10/1000 µs waveform conditions. Its unidirectional configuration provides forward conduction capability up to 40 A surge current and 3.5 V max forward voltage at 25 A, enabling bidirectional system protection when paired with complementary devices.
Thermal design is supported by a 150 °C maximum junction temperature, 1 W steady-state power dissipation, and JESD201 Class 2 whisker resistance. The device meets UL 94V-0 flammability rating and RoHS/halogen-free requirements per IEC 61249-2-21.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 8 V - Maximum continuous reverse operating voltage before clamping begins; sets safe margin below 12 V nominal supply rails. |
| VBR @ IT=1 mA | 8.89–10.90 V - Breakdown threshold range ensures reliable turn-on during transients while avoiding false triggering. |
| VC @ IPPM=50 A | 15.0 V - Clamped voltage limits downstream IC stress during 400 W peak pulses; maintains safe headroom for 12 V logic. |
| PPPM | 400 W - Peak pulse power rating for 10/1000 µs waveform; supports automotive load-dump and inductive switching events. |
| IR @ VWM | <1 µA - Ultra-low reverse leakage preserves battery life and minimizes standby power loss in always-on circuits. |
| Response Time | <1.0 ps - Enables effective suppression of ESD and fast-rising transients before sensitive circuitry is damaged. |
| Package | DO-214AC (SMA) - Standardized SMT footprint compatible with automated placement and reflow processes; cathode band marked. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with matte tin-plated leads, polarity indicated by cathode band. Weight ≈ 0.060 g. Moisture sensitivity level 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Forward current entry / Reverse bias reference | Connects to protected line's lower-potential side (e.g., GND or return path) in unidirectional configuration. |
| Cathode (banded end) | Clamping node / Transient sink | Connects to protected line's higher-potential side (e.g., 12 V rail); conducts surge current to ground during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive under-hood and powertrain applications per stress test requirements including temperature cycling and HTRB. |
| Glass passivated junction | Enhances long-term reliability and stability of VBR and leakage performance across thermal and humidity stress. |
| ISO 7637-2 compliance | Meets Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling) immunity standards. |
| Low clamping ratio (VC/VBR) | ~1.4–1.7 - Minimizes overvoltage overshoot during clamping, reducing risk of latch-up or gate oxide damage in downstream FETs/ICs. |
| J-STD-002 solderability | Ensures consistent wetting and joint integrity during lead-free reflow assembly without voiding or dewetting issues. |
Applications
| Automotive Body Control Module (BCM) | Industrial 12 V DC/DC Converter Input |
|---|---|
Use Scenario: Protects microcontroller I/O and CAN transceiver power rails against load dump and alternator ripple in BCM units. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between 12 V input and chassis ground, absorbing energy from ISO 7637-2 Pulse 1 (−100 V, 400 ms). Use Value: Limits clamped voltage to 15.0 V, preventing damage to 16 V-rated LDOs and 5 V logic supplies downstream of the input filter stage. |
Use Scenario: Shields primary-side MOSFET gate drivers and controller ICs from switching-induced transients in isolated flyback converters. IC Role / Device Role / Timing Role: Fast-response overvoltage clamp on the 12 V auxiliary input rail, triggered within <1 ps to suppress ringing from transformer leakage inductance. Use Value: Withstands 400 W peak pulses and maintains <1 µA leakage, ensuring minimal impact on no-load efficiency and standby current budgets. |
| LED Driver Power Supply Input | USB-C PD Adapter Secondary Side |
Use Scenario: Safeguards constant-current LED driver ICs from surges caused by hot-plug events or nearby relay switching in commercial lighting fixtures. IC Role / Device Role / Timing Role: Standoff-rated TVS on the 12–24 V DC bus, activated only during >8.89 V transients to avoid interfering with normal dimming control signals. Use Value: 8 V VWM allows full compatibility with PWM dimming ranges while clamping spikes to 15.0 V-well below typical LED string forward voltage thresholds. |
Use Scenario: Protects secondary-side synchronous rectifier controllers and USB-C CC logic from reflected transients during AC-DC adapter output short-circuit recovery. IC Role / Device Role / Timing Role: Unidirectional clamp on the 5–20 V programmable output rail, referenced to common-mode ground to prevent false triggering during PD negotiation. Use Value: Sub-1 ps response ensures clamping occurs before CC line voltage exceeds 5.5 V tolerance, preserving USB-IF compliance and port enumeration reliability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ8.0A | Lower VBR min (8.89 V vs. 8.89 V) but tighter max (9.83 V vs. 10.90 V); 13.6 V clamping at 50 A. | Offers lower clamping voltage (13.6 V) for tighter protection margins on 12 V rails with marginal headroom. | Select SMAJ8.0A when system-level testing confirms lower VC improves immunity without increasing false-trigger risk. |
| SMBJ8.0H | Same VWM/VBR specs but SMB package (DO-214AA); 400 W rating retained; 15.0 V VC at 50 A. | Larger footprint increases PCB area use but improves thermal dissipation for repetitive surge environments. | Choose SMBJ8.0H where board layout permits larger pad area and enhanced thermal mass is prioritized over miniaturization. |
Compared with SMAJ8.0H, SMAJ8.0A provides tighter clamping at the cost of reduced VBR tolerance margin, while SMBJ8.0H trades compactness for improved thermal handling-both require review of mechanical fit and system-level surge profile.
Availability
SMAJ8.0H is available at Aetrix Electronics and suitable for automotive body electronics, industrial DC/DC converters, and LED lighting power supplies requiring stable component supply, AEC-Q101 traceability, and ISO 7637-2 compliance.
Supply support for SMAJ8.0H 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in high-reliability protection, rectification, and power devices.
The SMAJ series was developed specifically for automotive and industrial transient suppression, emphasizing AEC-Q101 qualification, glass-passivated junction robustness, and precise clamping performance across wide temperature ranges.
FAQ
What is the maximum clamping voltage of the SMAJ8.0H under standard test conditions?
The SMAJ8.0H has a maximum clamping voltage (VC) of 15.0 V when subjected to a 50 A peak pulse current with a 10/1000 µs waveform. This value is measured per JEDEC standards and guarantees that downstream components see no more than 15.0 V during transient events, making SMAJ8.0H suitable for protecting 12 V systems with tight voltage tolerances.
Is the SMAJ8.0H unidirectional or bidirectional, and how does polarity affect its circuit placement?
The SMAJ8.0H is a unidirectional TVS diode, identified by the absence of "C" or "CA" suffix. Its cathode band must be connected toward the higher-potential side (e.g., 12 V rail), and anode to ground or return path. This configuration enables forward conduction during negative transients and reverse clamping during positive overvoltages-ensuring correct operation in SMAJ8.0H-based protection schemes.
Does the SMAJ8.0H meet automotive qualification standards, and which specific tests apply?
Yes, the SMAJ8.0H is AEC-Q101 qualified, covering stress tests including high-temperature reverse bias (HTRB), temperature cycling, and unbiased highly accelerated stress testing (uHAST). It also meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements-making SMAJ8.0H appropriate for automotive power distribution modules, body control units, and infotainment power supplies.
What is the leakage current specification for the SMAJ8.0H at its working stand-off voltage?
At its 8 V working stand-off voltage (VWM), the SMAJ8.0H exhibits a maximum reverse leakage current (IR) of 1 µA at 25 °C. This ultra-low leakage ensures minimal power loss in battery-backed or energy-sensitive applications, and contributes to long-term reliability in always-on automotive subsystems using SMAJ8.0H.
Can the SMAJ8.0H be used in place of SMAJ8.0A, and what is the key electrical distinction?
No direct substitution is recommended without validation: SMAJ8.0H has a VBR range of 8.89–10.90 V and clamps at 15.0 V, whereas SMAJ8.0A has a tighter VBR range of 8.89–9.83 V and clamps at 13.6 V. While both share the same VWM, the lower VC of SMAJ8.0A may improve protection margin-but reduces noise immunity. System-level testing with SMAJ8.0H is required before replacement.
SMAJ8.0H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 8V
- Voltage - Breakdown (Min):
- 8.89V
- Voltage - Clamping (Max) @ Ipp:
- 15V
- Current - Peak Pulse (10/1000µs):
- 26.7A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ8.0H FAQ
1.How can I place an order for SMAJ8.0H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ8.0H 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 SMAJ8.0H reliable?
The price and inventory of SMAJ8.0H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ8.0H is usually 5 days.
3.What payment methods are accepted for SMAJ8.0H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ8.0H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ8.0H?
SMAJ8.0H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ8.0H 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 SMAJ8.0H?
For technical support, including SMAJ8.0H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ8.0H requirements.
6.How does Aetrix verify that SMAJ8.0H is sourced from the original manufacturer or authorized distributors?
All SMAJ8.0H 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 SMAJ8.0H meets industry standards.
7.What is the process for return or replacement of SMAJ8.0H?
All SMAJ8.0H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ8.0H, 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 SMAJ8.0H part is unused and in its original packaging.
Return procedure for SMAJ8.0H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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