My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMAJ12-E3/5A
- Part No.:
- SMAJ12-E3/5A
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ12-E3/5A.pdf
- Description:
- TVS DIODE 12VWM 22VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,244
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ12-E3/5A from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping transient overvoltages on power and signal lines. It features 12 V stand-off voltage (VWM), 22.0 V maximum clamping voltage (VC) at 18.2 A peak pulse current, and 400 W peak pulse power rating with 10/1000 µs waveform - suitable for protecting MOSFETs and ICs in automotive power supplies.
For engineers reviewing the SMAJ12-E3/5A datasheet, SMAJ12-E3/5A pinout, SMAJ12-E3/5A application, or SMAJ12-E3/5A equivalent, key selection criteria include clamping voltage margin relative to protected device's absolute maximum rating, IPPM capability under system-level surge profiles (e.g., ISO 7637-2 Pulse 1/2a/5a), and thermal derating above 25 °C ambient.
Technical Context
This unidirectional TVS operates by avalanche breakdown when reverse voltage exceeds its 13.3–16.3 V breakdown range (VBR at 1 mA), maintaining low dynamic impedance during transients. Its glass-passivated junction ensures stable leakage (<1 µA at 12 V) and fast response time (<1 ns).
Thermal performance is defined by RθJA = 120 °C/W (on 0.2" × 0.2" copper pads) and RθJL = 30 °C/W, enabling reliable operation up to TJ = 150 °C. The device meets J-STD-020 MSL Level 1 and RoHS 2002/95/EC compliance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 12 V - Maximum continuous reverse operating voltage before significant leakage; sets upper limit for protected circuit's nominal DC rail. |
| VC @ IPPM | 22.0 V - Clamped voltage at 18.2 A peak pulse; must remain below protected device's absolute maximum input voltage. |
| IPPM | 18.2 A - Peak surge current survivable with 10/1000 µs waveform; determines minimum trace width and PCB copper area needed. |
| PPPM | 400 W - Peak pulse power dissipation; defines transient energy handling capacity per event without degradation. |
| TJ max. | 150 °C - Maximum junction temperature; constrains ambient operating range and thermal pad design for sustained surge duty. |
| IFSM | 40 A - Non-repetitive forward surge current (8.3 ms half-sine); relevant only for unidirectional configuration during fault conditions. |
Pinout & Package
DO-214AC (SMA) surface-mount package with matte tin-plated leads; cathode indicated by band on one end. Mounting requires 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal for rated power dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path (uni-directional) | Connected to lower-potential side of protected line; conducts during forward faults or ESD events with polarity reversal. |
| Cathode (banded end) | Avalanche clamping node | Connected to higher-potential side (e.g., VIN rail); initiates clamping when transient exceeds VWM. |
Key Features
| Feature | Design Value |
|---|---|
| 400 W peak pulse power (10/1000 µs) | Supports robust protection against ISO 7637-2 Pulse 5a (load dump) in 12 V automotive systems without derating below 78 V. |
| Low clamping ratio (VC/VWM = 1.83) | Minimizes overvoltage stress on downstream ICs compared to higher-ratio TVS devices, preserving margin to absolute maximum ratings. |
| MSL Level 1 moisture sensitivity | Enables standard SMT reflow without dry-pack or baking; compatible with high-volume automated assembly processes. |
| RoHS-compliant, commercial-grade (E3 suffix) | Meets EU environmental directives; qualified for industrial and consumer applications but not AEC-Q101 automotive grade. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Suppresses load dump transients (up to 60 V, 400 ms) on 12 V battery-fed ECUs and body control modules. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBAT and ground, clamping surges before they reach LDOs and microcontrollers. Use Value: Limits voltage seen by downstream regulators to ≤22.0 V, preventing latch-up or permanent damage during ISO 7637-2 Pulse 5a events. |
Use Scenario: Protects analog front-end inputs of temperature/pressure sensors connected to long harnesses in factory automation. IC Role / Device Role / Timing Role: Placed across sensor supply and return lines to shunt inductive switching spikes induced by nearby solenoids or relays. Use Value: Clamps transients within <1 ns to <22.0 V, avoiding ADC saturation or op-amp input stage damage while maintaining signal integrity. |
| Consumer Power Adapter Input Stage | Telecom Line Card Surge Protection |
Use Scenario: Guards primary-side controller ICs in AC-DC adapters against line surges (IEC 61000-4-5 Level 3, 2 kV/1 kA). IC Role / Device Role / Timing Role: Mounted across bulk capacitor terminals to clamp differential-mode surges entering via mains input. Use Value: Absorbs 400 W peak energy without failure, ensuring adapter continues operation after surge without requiring fuse replacement. |
Use Scenario: Shields Ethernet PHY interfaces on base station line cards from lightning-induced surges coupled onto twisted-pair cables. IC Role / Device Role / Timing Role: Used in conjunction with common-mode chokes and gas discharge tubes to provide coordinated secondary-stage protection. Use Value: Provides low-VC clamping (22.0 V) to protect 3.3 V or 5 V PHYs while surviving repetitive surges due to low incremental resistance. |
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-E3/5A | Lower VBR range (13.3–14.7 V), tighter tolerance; VC = 19.9 V at 20.1 A. | Better clamping margin for 12 V systems with narrow VIN tolerance (e.g., automotive infotainment with 11.5–12.5 V nominal). | Select SMAJ12A-E3/5A when lower clamping voltage is critical and system surge current exceeds 18.2 A. |
| SMCJ12A-E3/57T | Higher power rating (1500 W), DO-214AB (SMC) package; VC = 19.9 V at 75 A. | Required for higher-energy threats (e.g., IEC 61000-4-5 Level 4) where SMAJ12-E3/5A would fail. | Choose SMCJ12A-E3/57T when surge current exceeds 18.2 A or when board layout allows larger SMC footprint. |
Compared with SMAJ12-E3/5A, SMAJ12A-E3/5A offers improved clamping voltage but reduced surge current headroom, while SMCJ12A-E3/57T delivers significantly higher energy handling at the cost of larger PCB area and thermal mass - making each suitable for distinct threat-level tiers.
Availability
SMAJ12-E3/5A is available at Aetrix Electronics and suitable for automotive power rail protection, industrial sensor interface protection, and consumer power adapter input stage applications requiring stable component supply and full traceability.
Supply support for SMAJ12-E3/5A 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
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in diodes, rectifiers, and protection devices with emphasis on reliability and application-specific optimization.
The SMAJ series is engineered for surface-mount transient suppression in space-constrained environments, targeting automotive, industrial, and telecom systems where fast response and repeatable clamping are essential.
FAQ
What is the breakdown voltage range for SMAJ12-E3/5A?
The SMAJ12-E3/5A has a specified breakdown voltage (VBR) range of 13.3 V to 16.3 V at 1 mA test current, per Vishay Document 88390. This range ensures consistent avalanche initiation across manufacturing lots while accommodating thermal and process variation. The device is unidirectional, with the cathode marked by a band on the SMA package body.
Is SMAJ12-E3/5A suitable for automotive applications requiring AEC-Q101 qualification?
No, SMAJ12-E3/5A is a commercial-grade part (E3 suffix) and is not AEC-Q101 qualified. For automotive applications requiring AEC-Q101, the HE3-suffix variant (e.g., SMAJ12HE3/5A) must be selected. The E3 version meets RoHS and J-STD-020 MSL Level 1 but lacks the extended temperature cycling, humidity, and lifetime testing required for automotive under-hood use.
What is the maximum clamping voltage of SMAJ12-E3/5A and at what current is it measured?
The maximum clamping voltage (VC) of SMAJ12-E3/5A is 22.0 V, measured at a peak pulse current (IPPM) of 18.2 A with a 10/1000 µs waveform. This value is guaranteed across temperature and lot variations and defines the upper voltage limit imposed on protected circuitry during surge events.
How does the thermal resistance of SMAJ12-E3/5A affect PCB layout?
SMAJ12-E3/5A has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on 0.2" × 0.2" copper pads per terminal. To maintain TJ ≤ 150 °C under worst-case surge duty, PCB layout must provide adequate copper area and avoid thermal isolation - reducing pad size or omitting thermal vias increases junction temperature and risks parametric shift or failure.
Can SMAJ12-E3/5A be used in bidirectional configurations?
No, SMAJ12-E3/5A is a unidirectional TVS diode and is not rated for bidirectional operation. For bidirectional transient suppression, the CA-suffixed variant (e.g., SMAJ12CA-E3/5A) must be used. Using SMAJ12-E3/5A in reverse-biased configurations beyond its specified VWM will cause premature breakdown and potential failure.
SMAJ12-E3/5A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ12-E3/5A FAQ
1.How can I place an order for SMAJ12-E3/5A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ12-E3/5A 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 SMAJ12-E3/5A reliable?
The price and inventory of SMAJ12-E3/5A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ12-E3/5A is usually 5 days.
3.What payment methods are accepted for SMAJ12-E3/5A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ12-E3/5A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ12-E3/5A?
SMAJ12-E3/5A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ12-E3/5A 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 SMAJ12-E3/5A?
For technical support, including SMAJ12-E3/5A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ12-E3/5A requirements.
6.How does Aetrix verify that SMAJ12-E3/5A is sourced from the original manufacturer or authorized distributors?
All SMAJ12-E3/5A 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 SMAJ12-E3/5A meets industry standards.
7.What is the process for return or replacement of SMAJ12-E3/5A?
All SMAJ12-E3/5A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ12-E3/5A, 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 SMAJ12-E3/5A part is unused and in its original packaging.
Return procedure for SMAJ12-E3/5A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ12-E3/5A Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
