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Taiwan Semiconductor Corporation SMAJ12CA
- Part No.:
- SMAJ12CA
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ12CA.pdf
- Description:
- TVS DIODE 12VWM 19.9VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,090
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Product details
Overview
SMAJ12CA from Taiwan Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for robust overvoltage protection in DC power rails. It features a 12 V working stand-off voltage (VWM), 13.3–14.7 V breakdown voltage (VBR @ 1 mA), 19.9 V maximum clamping voltage (VC @ 20.1 A), 400 W peak pulse power (10/1000 µs), and <1 µA reverse leakage at VWM, making it suitable for protecting automotive power supplies and industrial DC/DC converters.
For engineers reviewing the SMAJ12CA datasheet, SMAJ12CA pinout, SMAJ12CA application, or SMAJ12CA equivalent, key selection criteria include bidirectional clamping capability, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, DO-214AC mechanical compatibility, TJ = –55°C to +150°C operating range, and verified 19.9 V clamping under 20.1 A surge current.
Technical Context
The SMAJ12CA operates as a silicon avalanche diode with glass-passivated junction, enabling fast response (<1.0 ps from 0 V to VBR min) and stable clamping across temperature. Its bidirectional configuration (denoted by "CA" suffix) ensures symmetrical protection for AC-coupled or floating DC lines without polarity dependency.
It delivers 400 W peak pulse power per 10/1000 µs waveform up to 78 V VWM; above that, rating reduces to 300 W. The device meets JESD201 Class 2 whisker resistance, UL 94V-0 molding compound, and moisture sensitivity level 1 per J-STD-020 - confirming suitability for high-reliability surface-mount assembly.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - Maximum continuous reverse voltage before significant leakage; defines protected rail's nominal operating limit. |
| VBR @ IT = 1 mA | 13.3–14.7 V - Breakdown onset range; ensures reliable conduction onset during transients without false triggering. |
| VC @ IPPM = 20.1 A | 19.9 V - Clamped voltage under full-rated surge; limits downstream IC stress to safe levels. |
| PPPM (10/1000 µs) | 400 W - Peak surge energy handling capacity; supports automotive load-dump and inductive switching events. |
| IR @ VWM | <1 µA - Ultra-low leakage ensures minimal standby power loss and no interference with sensitive analog monitoring. |
| Junction Temp Range | –55°C to +150°C - Enables deployment in under-hood automotive, industrial motor drives, and outdoor power electronics. |
Pinout & Package
Package: DO-214AC (SMA), surface-mount, bi-directional, cathode band not applicable (bidirectional symmetry). Matte tin-plated leads, RoHS and halogen-free compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Bidirectional avalanche junction terminals | No polarity marking required; either terminal serves as input/output for transient suppression on balanced lines or floating rails. |
| Case (body) | Non-connected mechanical structure | DO-214AC outline provides standardized thermal mass and solder pad footprint; no electrical connection to case. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures long-term stability of VBR and leakage under thermal cycling and humidity exposure. |
| ISO 7637-2 compliance (Pulse 1/2a/2b/3a/3b) | Validated for automotive ECU-level surge immunity - eliminates need for external test validation. |
| Fast response time <1.0 ps | Clamps transients before propagation into protected circuitry - critical for safeguarding high-speed logic and microcontrollers. |
| Moisture sensitivity level 1 | Enables standard SMT reflow without baking or special handling - reduces manufacturing cost and risk of popcorning. |
Applications
| Automotive Power Distribution | Industrial DC/DC Converters |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs against load dump and alternator ripple. IC Role / Device Role / Timing Role: Bidirectional TVS clamp placed at input filter stage to shunt surges before L-C filtering. Use Value: Limits transient voltage to ≤19.9 V, preventing damage to 3.3 V/5 V regulators and CAN transceivers downstream. | Use Scenario: Safeguarding isolated 24 V to 5 V flyback converter inputs in PLC modules. IC Role / Device Role / Timing Role: Primary-side surge absorber parallel to bulk capacitor, triggered within picoseconds. Use Value: Maintains system uptime by surviving repetitive 400 W pulses without degradation - validated per IEC 61000-4-5. |
| LED Driver Power Inputs | Telecom Power Feeds |
Use Scenario: Input protection for constant-current LED drivers in streetlight systems exposed to lightning-induced surges. IC Role / Device Role / Timing Role: First-line defense against differential-mode transients on 24–48 V DC bus. Use Value: Withstands ≥1000 surges at rated IPPM while maintaining VC ≤19.9 V - extends driver lifetime in outdoor deployments. | Use Scenario: Overvoltage clamping on -48 V telecom power feeds subject to accidental short-circuit recovery spikes. IC Role / Device Role / Timing Role: Bidirectional clamp across supply rails to absorb both positive and negative polarity transients. Use Value: Symmetrical VBR and VC ensure equal protection regardless of fault polarity - eliminates need for dual unidirectional devices. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A | Unidirectional; same VWM/VBR/VC specs but requires correct polarity orientation. | Only suitable where circuit ground reference is fixed and polarity is known (e.g., single-rail SMPS outputs). | Select SMAJ12A only if polarity is strictly controlled and cathode-to-ground layout is guaranteed. |
| SMBJ12CA | Same electrical specs but in larger DO-214AA (SMB) package; 600 W PPPM rating (10/1000 µs). | Better thermal dissipation and higher surge margin; requires larger PCB footprint and different pad layout. | Choose SMBJ12CA when higher single-pulse energy (600 W) or improved thermal performance is required. |
Compared with SMAJ12A, SMAJ12CA offers polarity-agnostic protection ideal for floating or AC-coupled nodes; compared with SMBJ12CA, it trades 200 W peak power for space-constrained DO-214AC mounting - optimal for compact automotive modules and dense industrial PCBs.
Availability
SMAJ12CA is available at Aetrix Electronics and suitable for automotive power distribution, industrial DC/DC converters, LED driver inputs, and telecom power feed applications requiring stable component supply, full traceability, and long-term lifecycle support.
Supply support for SMAJ12CA 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 for industrial and automotive markets.
The SMAJ series is engineered specifically for high-reliability transient suppression in harsh environments - emphasizing ISO 7637-2 compliance, extended temperature operation, and surface-mount manufacturability.
FAQ
What does the "CA" suffix indicate in SMAJ12CA?
The "CA" suffix denotes a bidirectional configuration: SMAJ12CA has symmetrical avalanche characteristics in both forward and reverse bias, enabling use on floating or AC-coupled lines without polarity constraints. Unlike unidirectional variants (e.g., SMAJ12A), SMAJ12CA does not require cathode/anode orientation during placement - simplifying layout and eliminating polarity-related field failures.
What is the maximum clamping voltage of SMAJ12CA under rated surge current?
The maximum clamping voltage (VC) of SMAJ12CA is 19.9 V when subjected to its rated peak pulse current of 20.1 A (10/1000 µs waveform). This value is guaranteed across the full operating temperature range (–55°C to +150°C) and ensures downstream components see no more than 19.9 V during transient events - critical for protecting 24 V system logic and interface ICs.
Is SMAJ12CA compliant with automotive surge immunity standards?
Yes, SMAJ12CA meets ISO 7637-2 requirements for Pulse 1 (inductive load disconnect), Pulse 2a (sudden load removal), Pulse 2b (supply line interruption), Pulse 3a (switching noise), and Pulse 3b (ground bounce). This compliance is verified per manufacturer test data and makes SMAJ12CA suitable for front-end protection in automotive body control modules, infotainment power supplies, and ADAS sensor hubs.
What is the junction temperature rating for SMAJ12CA?
SMAJ12CA has a maximum junction temperature (TJ) rating of +150°C and a minimum of –55°C. This wide range supports operation in under-hood automotive environments, industrial motor controls, and outdoor lighting systems. Derating curves in the datasheet define allowable peak pulse power above 25°C ambient - e.g., ~320 W at +85°C ambient.
Does SMAJ12CA require special handling during PCB assembly?
No - SMAJ12CA is rated at Moisture Sensitivity Level 1 (per J-STD-020), meaning it can be stored indefinitely at ≤30°C/85% RH and processed using standard SMT reflow profiles without pre-baking. Its matte tin-plated leads comply with J-STD-002 for solderability, and the DO-214AC package is compatible with automated pick-and-place equipment.
SMAJ12CA 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:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 19.9V
- Current - Peak Pulse (10/1000µs):
- 20.1A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ12CA FAQ
1.How can I place an order for SMAJ12CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ12CA 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 SMAJ12CA reliable?
The price and inventory of SMAJ12CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ12CA is usually 5 days.
3.What payment methods are accepted for SMAJ12CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ12CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ12CA?
SMAJ12CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ12CA 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 SMAJ12CA?
For technical support, including SMAJ12CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ12CA requirements.
6.How does Aetrix verify that SMAJ12CA is sourced from the original manufacturer or authorized distributors?
All SMAJ12CA 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 SMAJ12CA meets industry standards.
7.What is the process for return or replacement of SMAJ12CA?
All SMAJ12CA units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ12CA, 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 SMAJ12CA part is unused and in its original packaging.
Return procedure for SMAJ12CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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