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Diodes Incorporated SMAJ12A-13
- Part No.:
- SMAJ12A-13
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ12A-13.pdf
- Description:
- TVS DIODE 12VWM 19.9VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:6,951
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Product details
Overview
SMAJ12A-13 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power rails and signal lines. It features a 12V reverse standoff voltage (VRWM), 13.3–14.7V breakdown voltage (VBR) at 1mA, 19.9V max clamping voltage (VC) at 20.1A peak pulse current (IPP), and operates from –55°C to +150°C - used in automotive infotainment power inputs and industrial PLC I/O protection.
For engineers reviewing the SMAJ12A-13 datasheet, SMAJ12A-13 pinout, SMAJ12A-13 application, or SMAJ12A-13 equivalent, key selection criteria include clamping voltage margin vs. protected IC VDD tolerance, unidirectional polarity alignment with DC rail direction, 400W peak pulse rating for IEC 61000-4-5 Level 3 surge compliance, and SMA package thermal performance under sustained transient stress.
Technical Context
This TVS diode employs a glass-passivated silicon junction optimized for fast response (<1 ps) to ESD and lightning-induced transients. Its unidirectional configuration provides low-leakage (<5 µA @ 12V) blocking in normal operation while clamping reversely biased surges above VBR.
The device meets JEDEC-standard 8.3ms half-sine surge testing (IFSM = 40A), derates linearly above 25°C ambient per Fig. 1, and maintains stable clamping up to 150°C junction temperature - enabling placement near hot-running DC/DC converters without performance drift.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W - sustains single 8.3ms surge events per IEC 61000-4-5 without failure |
| Reverse Standoff Voltage | 12V - maximum continuous DC voltage before leakage exceeds 5 µA |
| Breakdown Voltage | 13.3–14.7V @ 1mA - precise VBR window ensures reliable turn-on before downstream IC damage |
| Clamping Voltage | 19.9V @ 20.1A - limits transient voltage seen by protected circuitry during worst-case surge |
| Junction Temp Range | –55°C to +150°C - supports under-hood automotive and industrial control cabinet deployment |
| Package | SMA (DO-214AC) - surface-mount footprint with 5.59mm max body length and 2.30mm max terminal width |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case, UL 94V-0 rated, cathode band marking on unidirectional variant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference node | Connected to ground or lower-potential rail; defines conduction path during reverse surge |
| Cathode | Protected line input | Connected to supply rail or signal line; clamps voltage when transient exceeds VBR |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated die | Enables stable VBR and low leakage across temperature and lifetime, critical for automotive AEC-Q200 reliability |
| 400W peak pulse rating | Meets IEC 61000-4-5 Level 3 (1kV/2Ω) surge immunity without derating in PCB layouts with <10 mm trace length |
| Fast response time | <1 ps junction response ensures clamping initiates before ESD pulses (IEC 61000-4-2) propagate into sensitive logic |
| RoHS-compliant matte tin finish | Supports lead-free reflow profiles (peak 260°C) without solder joint degradation or whisker risk |
Applications
| Automotive Infotainment Power Input | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: 12V battery-fed head unit power rail exposed to load dump (ISO 7637-2 Pulse 5a). IC Role / Device Role / Timing Role: Primary clamping device placed upstream of DC/DC converter input. Use Value: Limits transient to ≤19.9V, preventing MOSFET gate oxide rupture and maintaining system boot integrity. | Use Scenario: 24V digital input channel subject to field-wiring induced surges during maintenance. IC Role / Device Role / Timing Role: First-line protection between terminal block and optocoupler input stage. Use Value: Absorbs >95% of 40A surge energy within 10 ns, preserving optocoupler CTR and isolation barrier life. |
| Telecom PoE Data Line Surge Suppression | Medical Patient Monitor Sensor Interface |
Use Scenario: 48V PoE+ data pair (Mode A) subjected to lightning-induced common-mode transients. IC Role / Device Role / Timing Role: Unidirectional clamp on each conductor relative to local ground plane. Use Value: Maintains <10 pF junction capacitance to avoid Ethernet signal integrity loss at 100 MHz. | Use Scenario: Analog front-end input for ECG electrode connection exposed to defibrillation pulse coupling. IC Role / Device Role / Timing Role: Secondary protection layer after gas discharge tube (GDT) coarse suppression. Use Value: Provides sub-20V clamping with <1 nA leakage at 12V, ensuring baseline stability in microvolt-level biopotential measurement. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ12A-TP from Microchip | Same VRWM (12V), slightly higher VC (20.5V @ 20A), tighter VBR tolerance (13.5–14.5V) | Preferred where tighter VBR matching reduces design margin uncertainty | Select when sourcing consistency across multiple suppliers is required for long-lifecycle medical devices |
| P6SMB12A from Vishay | Identical electrical specs but larger SMB package (6.2mm x 3.5mm), 1.5W steady-state rating vs. 1.0W | Better thermal dissipation in high-ambient environments (>85°C board temp) | Choose for industrial motor drives where sustained surge repetition occurs near heat sinks |
Compared with SMAJ12A-13, SMAJ12A-TP offers tighter VBR control for precision-critical designs, while P6SMB12A trades smaller footprint for superior thermal handling - making SMAJ12A-13 optimal for space-constrained automotive modules requiring proven DO-214AC reliability.
Availability
SMAJ12A-13 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLC I/O modules, and telecom PoE-powered equipment requiring stable component supply across multi-year production cycles.
Supply support for SMAJ12A-13 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design centers across Asia and manufacturing in China, Taiwan, and the U.S.
The SMAJ series belongs to Diodes' transient voltage suppression portfolio, engineered specifically for robust, cost-effective overvoltage protection in automotive, industrial, and communications infrastructure applications where reliability under harsh EMC conditions is mandatory.
FAQ
What is the maximum clamping voltage of SMAJ12A-13 at its rated peak pulse current?
The maximum clamping voltage (VC) is 19.9V at 20.1A peak pulse current (IPP), measured under the standard 8.3ms half-sine waveform per IEC 61000-4-5. This value is guaranteed across the full operating temperature range (–55°C to +150°C) and defines the upper voltage limit imposed on protected circuitry during surge events.
Is SMAJ12A-13 RoHS compliant and lead-free compatible?
Yes, SMAJ12A-13 uses a matte tin lead finish and complies with RoHS Directive 2011/65/EU (Revision 13.2.2003), including exemptions for high-temperature solder and glass. It supports standard lead-free reflow profiles with peak temperatures up to 260°C and passes JEDEC J-STD-020C moisture sensitivity level 1 requirements.
How does the SMAJ12A-13 differ from the bi-directional SMAJ12CA-13?
SMAJ12A-13 is unidirectional with a cathode band marking and blocks current below –12V in reverse bias, while SMAJ12CA-13 is bi-directional with no polarity indicator and clamps symmetrically at ±12V. The unidirectional version exhibits lower leakage (<5 µA @ 12V) and is preferred for DC power rail protection; the bi-directional variant suits AC signal lines or differential buses.
Can SMAJ12A-13 be used in parallel to increase surge current handling?
No - paralleling SMAJ12A-13 devices is not recommended due to VBR mismatch causing current imbalance and premature failure of the lower-VBR unit. For higher IPP, select a single higher-rated device (e.g., SMAJ15A-13) or use a TVS array with matched characteristics and integrated current-sharing design.
SMAJ12A-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- 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:
- SMA
SMAJ12A-13 FAQ
1.How can I place an order for SMAJ12A-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ12A-13 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 SMAJ12A-13 reliable?
The price and inventory of SMAJ12A-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ12A-13 is usually 5 days.
3.What payment methods are accepted for SMAJ12A-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ12A-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ12A-13?
SMAJ12A-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ12A-13 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 SMAJ12A-13?
For technical support, including SMAJ12A-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ12A-13 requirements.
6.How does Aetrix verify that SMAJ12A-13 is sourced from the original manufacturer or authorized distributors?
All SMAJ12A-13 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 SMAJ12A-13 meets industry standards.
7.What is the process for return or replacement of SMAJ12A-13?
All SMAJ12A-13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ12A-13, 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 SMAJ12A-13 part is unused and in its original packaging.
Return procedure for SMAJ12A-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ12A-13 Tags
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