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Diodes Incorporated SMAJ40A-13-F
- Part No.:
- SMAJ40A-13-F
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ40A-13-F.pdf
- Description:
- TVS DIODE 40VWM 64.5VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:37,780
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Product details
Overview
SMAJ40A-13-F from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode designed for primary overvoltage protection in DC power lines and signal interfaces. It features a 40V reverse standoff voltage (VRWM), 44.4V minimum breakdown voltage (VBR), 64.5V maximum clamping voltage (VC) at 6.2A peak pulse current (IPP), and operates across –55°C to +150°C. It is commonly deployed in automotive power supply rails and industrial sensor I/O protection.
For engineers reviewing the SMAJ40A-13-F datasheet, SMAJ40A-13-F pinout, SMAJ40A-13-F application, or SMAJ40A-13-F equivalent, key selection criteria include clamping voltage margin relative to protected IC VCC, peak pulse current handling under ISO 7637-2 Pulse 1/2a/5a waveforms, thermal derating above +25°C ambient, and compatibility with automated SMT reflow profiles for SMA package.
Technical Context
This TVS diode uses glass-passivated silicon junction construction to achieve sub-nanosecond response time and stable clamping performance under repetitive surge events. Its unidirectional configuration provides low forward voltage (VF = 3.5V @ 35A) for DC-biased applications while maintaining high surge robustness (IFSM = 40A, 8.3ms half-sine).
The device complies with JEDEC Level 1 moisture sensitivity and is rated for 1.0W steady-state power dissipation at TL = +75°C. Its clamping behavior is characterized using the standardized 10/1000μs double-exponential waveform per REA standards, with derating applied above +25°C ambient per Fig. 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W - Sustains single 10/1000μs transients without failure; defines maximum energy absorption capability. |
| Reverse Standoff Voltage (VRWM) | 40V - Maximum continuous DC or RMS voltage before significant leakage; sets upper limit for normal operating bias. |
| Clamping Voltage (VC) | 64.5V @ IPP = 6.2A - Voltage seen by downstream circuit during worst-case surge; must remain below protected IC absolute max rating. |
| Breakdown Voltage (VBR) | 44.4V min @ IT = 1.0mA - Onset of avalanche conduction; ensures reliable triggering before VRWM violation. |
| Peak Forward Surge Current (IFSM) | 40A @ 8.3ms half-sine - Withstands AC line fault surges or load dump events in automotive power systems. |
| Operating Temperature Range | –55°C to +150°C - Validated for under-hood automotive and industrial environments with minimal parameter drift. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with UL 94V-0 flammability rating, cathode band marking for polarity identification. Weight: 0.064g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during forward conduction | Connected to ground or low-side return path in unidirectional clamp configuration. |
| Cathode | Current exit point during forward conduction; high-impedance terminal during reverse bias | Connected to protected line (e.g., 12V rail); clamps to anode when voltage exceeds VRWM. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated die construction | Ensures stable leakage current (<5µA @ VRWM) and long-term reliability under thermal cycling and humidity exposure. |
| Lead-free, RoHS-compliant plating | Matte tin finish meets MIL-STD-202 solderability requirements and supports Pb-free reflow profiles (JEDEC J-STD-020). |
| Fast response time | Sub-nanosecond turn-on enables effective suppression of ESD (IEC 61000-4-2) and fast-rising transients (e.g., ISO 10605). |
| Low clamping ratio (VC/VBR) | 1.45 (64.5V / 44.4V) - Minimizes overvoltage stress on downstream components while maintaining margin to breakdown. |
Applications
| Automotive Power Rail Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: 12V battery-fed control modules exposed to load dump (ISO 7637-2 Pulse 5a) and alternator ripple. IC Role / Device Role: Primary overvoltage clamp placed between fused input and DC-DC converter input. Use Value: Limits transient voltage to ≤64.5V, protecting 75V-rated input capacitors and regulator ICs without sacrificing steady-state efficiency. |
Use Scenario: 4–20mA current loop transmitters interfacing with PLC analog inputs in factory automation. IC Role / Device Role: Input-side TVS on current-loop terminals to absorb induced surges from nearby motor switching. Use Value: Maintains <5µA leakage at 24V nominal, avoiding loop current error; clamps 1kV/500A surge within 10/1000μs envelope. |
| USB Port ESD Protection | DC Motor Driver Back-EMF Suppression |
Use Scenario: USB 2.0 data lines (D+/D−) on embedded host controllers in medical devices. IC Role / Device Role: Secondary-level ESD clamp after common-mode choke, placed adjacent to USB PHY. Use Value: Provides 30kV contact ESD immunity (IEC 61000-4-2) with <0.5pF inter-electrode capacitance-no signal integrity degradation. |
Use Scenario: Flyback suppression across brushed DC motor terminals in automotive seat adjusters. IC Role / Device Role: Unidirectional TVS connected anode-to-ground, cathode-to-motor terminal. Use Value: Absorbs 40A inductive kick (8.3ms) without degradation; withstands repeated commutation events at 150°C junction temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40CA-13-F | Bidirectional version; symmetric clamping in both polarities; same VRWM, VC, and PPK ratings. | Required for AC-coupled or dual-polarity signal lines (e.g., RS-485, CAN bus) where reverse voltage may occur. | Select only if bidirectional protection is mandated; otherwise unidirectional offers lower cost and tighter leakage control. |
| SMBJ40A-13-F | Same electrical specs but SMB package (higher thermal mass, 600W PPK rating, larger footprint). | Preferred for higher-reliability industrial designs requiring greater surge margin or improved thermal dissipation. | Choose when board space permits and 600W surge headroom or extended lifetime under repetitive stress is required. |
Compared with SMAJ40A-13-F, SMAJ40CA-13-F adds bidirectional symmetry at the cost of slightly higher leakage in AC mode, while SMBJ40A-13-F trades compactness for 50% higher pulse power and better thermal stability-both require layout and BOM review for mechanical fit and system-level surge compliance.
Availability
SMAJ40A-13-F is available at Aetrix Electronics and suitable for automotive body control modules, industrial fieldbus nodes, USB peripheral power management, and DC motor drive circuits requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMAJ40A-13-F 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 semiconductor company specializing in discrete, analog, and mixed-signal solutions, with manufacturing certified to IATF 16949 and product qualification to AEC-Q101 for automotive-grade components.
The SMAJ series is part of Diodes' transient voltage suppression portfolio, engineered specifically for robust, surface-mount overvoltage protection in automotive, industrial, and communications infrastructure applications where reliability under harsh electrical stress is critical.
FAQ
What is the maximum clamping voltage of SMAJ40A-13-F at its rated peak pulse current?
The maximum clamping voltage (VC) is 64.5V at a peak pulse current (IPP) of 6.2A, measured using the standardized 10/1000μs double-exponential waveform. This value is guaranteed across the full operating temperature range and defines the upper voltage limit imposed on protected circuitry during surge events.
Is SMAJ40A-13-F suitable for automotive applications requiring AEC-Q101 qualification?
No-SMAJ40A-13-F is the standard industrial-grade variant. For AEC-Q101 qualified versions, Diodes offers the SMAJ40AQ-13-F, which undergoes additional stress testing, PPAP documentation, and is manufactured in IATF 16949-certified facilities. Always verify qualification status via official Diodes part numbering and datasheet revision.
How does the SMA package affect thermal performance compared to SMB or SMC packages?
The SMA package has lower thermal resistance (RθJA ≈ 125°C/W typical) than SMB (≈90°C/W) or SMC (≈60°C/W), limiting its steady-state power dissipation to 1.0W at TL = +75°C. While sufficient for most transient-only applications, it requires careful PCB copper area design and avoids sustained high-temperature operation where SMB/SMC variants provide superior heat spreading.
Can SMAJ40A-13-F be used in bidirectional signal lines like RS-485?
No-it is unidirectional and will conduct continuously if reverse-biased beyond its forward voltage (~3.5V). For bidirectional lines, use the SMAJ40CA-13-F variant, which provides symmetrical clamping in both directions and is explicitly rated for AC-coupled or differential bus applications without DC bias constraints.
SMAJ40A-13-F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 6.2A
- 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:
- SMA
SMAJ40A-13-F FAQ
1.How can I place an order for SMAJ40A-13-F through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ40A-13-F 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 SMAJ40A-13-F reliable?
The price and inventory of SMAJ40A-13-F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ40A-13-F is usually 5 days.
3.What payment methods are accepted for SMAJ40A-13-F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ40A-13-F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ40A-13-F?
SMAJ40A-13-F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ40A-13-F 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 SMAJ40A-13-F?
For technical support, including SMAJ40A-13-F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ40A-13-F requirements.
6.How does Aetrix verify that SMAJ40A-13-F is sourced from the original manufacturer or authorized distributors?
All SMAJ40A-13-F 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 SMAJ40A-13-F meets industry standards.
7.What is the process for return or replacement of SMAJ40A-13-F?
All SMAJ40A-13-F units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ40A-13-F, 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 SMAJ40A-13-F part is unused and in its original packaging.
Return procedure for SMAJ40A-13-F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ40A-13-F Tags
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ESD9B5.0ST5G
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Diodes Incorporated
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Diodes Incorporated
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