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Taiwan Semiconductor Corporation SMAJ12H
- Part No.:
- SMAJ12H
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ12H.pdf
- Description:
- TVS DIODE 12VWM 22VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:6,487
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Product details
Overview
SMAJ12H from Taiwan Semiconductor is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, with 12V working stand-off voltage (VWM), 13.3–16.3V breakdown voltage (VBR), and 22.0V clamping voltage (VC) at 18.2A peak pulse current. It delivers AEC-Q101 qualification and meets ISO 7637-2 Pulse 1/2a/2b/3a/3b for automotive power line protection.
For engineers reviewing the SMAJ12H datasheet, SMAJ12H pinout, SMAJ12H application, or SMAJ12H equivalent, key selection criteria include clamping performance under 10/1000μs surge, unidirectional polarity marking, AEC-Q101 compliance for automotive ECUs, and DO-214AC thermal/power derating above 25°C.
Technical Context
The SMAJ12H operates as a unidirectional avalanche diode, activated when reverse voltage exceeds its VBR range (13.3–16.3V @ 1mA). Its glass-passivated junction enables sub-1ps response time and <1μA leakage at 12V, supporting robust ESD and load-dump immunity in DC power rails.
Designed for single-die configuration in DO-214AC, it sustains 400W peak pulse power (10/1000μs), derated linearly above 25°C ambient per Fig.2, with maximum junction temperature of 150°C and moisture sensitivity level 1 per J-STD-020.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR min/max | 13.3 / 16.3 V @ 1 mA - Ensures reliable turn-on margin above VWM for stable overvoltage detection |
| VC @ IPPM | 22.0 V @ 18.2 A - Clamped voltage during 10/1000μs surge limits downstream IC stress |
| PPPM | 400 W (10/1000μs) - Sustains automotive load-dump transients without failure |
| IR @ VWM | <1 μA - Negligible leakage preserves battery life in always-on vehicle modules |
| TJ max | 150 °C - Enables operation in under-hood environments with minimal thermal derating |
| Package | DO-214AC (SMA) - Standardized footprint compatible with automated SMT placement and reflow |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case with matte tin-plated leads, cathode band marking polarity, 0.060g weight, UL 94V-0 rated compound, and JESD201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path | Connected to ground or low-side return in unidirectional TVS configuration |
| Cathode | Reverse-biased clamping node | Connected to protected line (e.g., 12V rail); marked by band for orientation |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing |
| Clamping voltage 22.0 V @ 18.2 A | Keeps protected circuitry below 24 V during ISO 7637-2 Pulse 5a (load dump) |
| Glass passivated junction | Ensures stable VBR tolerance and long-term leakage stability across 150°C operation |
| Fast response <1 ps | Responds before most microsecond-scale transients propagate into sensitive analog or digital ICs |
| Moisture sensitivity level 1 | Eliminates bake requirements prior to reflow, reducing manufacturing cost and risk |
Applications
| Automotive Body Control Module (BCM) | Industrial DC/DC Converter Input Stage |
|---|---|
Use Scenario: Protecting LIN bus interface and power supply inputs against load dump and jump-start surges in BCM units. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 12V rail and ground, clamping transients before they reach MCU power pins and LIN transceivers. Use Value: Maintains system uptime by limiting rail voltage to 22.0 V during 400W 10/1000μs pulses, satisfying ISO 16750-2 requirement for 12V systems. | Use Scenario: Safeguarding primary-side MOSFET gate drivers and controller ICs in isolated 24V-to-5V DC/DC converters used in factory automation. IC Role / Device Role / Timing Role: Standoff-rated TVS on input bulk capacitor node, absorbing switching noise and external surge coupling. Use Value: Prevents false triggering and latch-up in PWM controllers by suppressing >13.3V excursions with <1μA leakage at nominal 12V input. |
| LED Headlamp Driver Power Input | Smart Meter Power Supply Protection |
Use Scenario: Shielding constant-current LED driver ICs from alternator-induced spikes and battery reversal events in automotive headlamps. IC Role / Device Role / Timing Role: Unidirectional clamping device mounted directly at connector entry point, referenced to chassis ground. Use Value: Withstands repeated 10/1000μs pulses up to 400W while maintaining VWM = 12 V, enabling compact layout without series impedance. | Use Scenario: Securing AC/DC adapter output and meter SoC power rails against lightning-induced surges on utility-connected smart meters. IC Role / Device Role / Timing Role: Secondary-side TVS on regulated 3.3V or 5V supply, providing final-stage overvoltage defense after primary MOVs. Use Value: Delivers precise 22.0V clamping with ±1.5V VBR tolerance, ensuring downstream PMICs remain within absolute maximum ratings during fast-rising transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12AH | Narrower VBR range (13.3–14.7 V), lower VC (19.9 V @ 20.1 A), same DO-214AC package | Better clamping margin for low-voltage tolerant loads; tighter VBR improves predictability in precision rail protection | Select SMAJ12AH when clamping voltage headroom is critical and tighter VBR tolerance is required |
| SMBJ12H | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; 600W PPPM rating | Higher power handling supports longer-duration transients; requires larger PCB area and different pad layout | Choose SMBJ12H only if 600W surge capability is mandatory and board space allows SMB footprint |
Compared with SMAJ12AH and SMBJ12H, the SMAJ12H offers balanced 400W surge capacity, industry-standard DO-214AC fit, and optimal clamping for 12V automotive and industrial rails-making it the default choice where space, cost, and AEC-Q101 compliance are jointly prioritized.
Availability
SMAJ12H is available at Aetrix Electronics and suitable for automotive body electronics, industrial DC/DC converters, LED lighting drivers, and smart meter power supplies requiring stable component supply and AEC-Q101 assurance.
Supply support for SMAJ12H 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 semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs, with global distribution and AEC-Q101 validation capabilities.
The SMAJ series was developed specifically for high-reliability 12V–188V automotive and industrial transient suppression, emphasizing fast response, low leakage, and standardized surface-mount packaging for automated assembly.
FAQ
What is the clamping voltage of the SMAJ12H under standard test conditions?
The SMAJ12H has a maximum clamping voltage (VC) of 22.0 V when subjected to its rated peak pulse current of 18.2 A using the 10/1000μs waveform. This value is measured at TA = 25°C and ensures protected circuits remain within safe voltage limits during common automotive transients such as ISO 7637-2 Pulse 1 and 2b. The SMAJ12H maintains this performance across its specified junction temperature range.
Is the SMAJ12H suitable for bidirectional transient protection?
No, the SMAJ12H is a unidirectional TVS diode intended for DC line protection with defined polarity. For bidirectional applications, Taiwan Semiconductor specifies parts with CH or CAH suffixes (e.g., SMAJ12CH). Using SMAJ12H in reverse-biased AC configurations may result in unintended forward conduction or insufficient protection; always verify polarity alignment in schematic and layout for SMAJ12H.
Does the SMAJ12H meet AEC-Q101 reliability standards?
Yes, the SMAJ12H is explicitly qualified to AEC-Q101 for stress testing including temperature cycling, high-temperature reverse bias (HTRB), and ESD. This qualification confirms its suitability for automotive electronic control units, body modules, and lighting systems where long-term reliability under thermal and electrical stress is mandatory. The SMAJ12H datasheet Version A2102 documents full AEC-Q101 compliance.
What is the maximum steady-state power dissipation for the SMAJ12H?
The SMAJ12H has a steady-state power dissipation (PD) rating of 1 W at TA = 25°C. This value applies to continuous DC or low-frequency reverse-bias conditions-not surge events. Actual usable PD decreases with rising ambient temperature per the derating curve in Figure 2 of the datasheet, and thermal design must account for PCB copper area and airflow to maintain TJ ≤ 150°C during sustained operation.
How does the SMAJ12H compare to the SMAJ12AH in terms of electrical performance?
The SMAJ12AH features a tighter breakdown voltage range (13.3–14.7 V vs. 13.3–16.3 V for SMAJ12H) and lower clamping voltage (19.9 V vs. 22.0 V at rated current), resulting in improved overvoltage margin for sensitive loads. Both share identical VWM (12 V), package (DO-214AC), and AEC-Q101 qualification. The SMAJ12H remains preferred when broader VBR tolerance is acceptable and legacy design compatibility is required.
SMAJ12H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 22V
- Current - Peak Pulse (10/1000µs):
- 18.2A
- 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)
SMAJ12H FAQ
1.How can I place an order for SMAJ12H through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ12H 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 SMAJ12H reliable?
The price and inventory of SMAJ12H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ12H is usually 5 days.
3.What payment methods are accepted for SMAJ12H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ12H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ12H?
SMAJ12H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ12H 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 SMAJ12H?
For technical support, including SMAJ12H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ12H requirements.
6.How does Aetrix verify that SMAJ12H is sourced from the original manufacturer or authorized distributors?
All SMAJ12H 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 SMAJ12H meets industry standards.
7.What is the process for return or replacement of SMAJ12H?
All SMAJ12H units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ12H, 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 SMAJ12H part is unused and in its original packaging.
Return procedure for SMAJ12H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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