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Diodes Incorporated SMAJ40A-13
- Part No.:
- SMAJ40A-13
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ40A-13.pdf
- Description:
- TVS DIODE 40VWM 64.5VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:9,854
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Product details
Overview
SMAJ40A-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 40V reverse standoff voltage (VRWM), 44.4–49.1V breakdown voltage (VBR) at 1mA, 64.5V maximum clamping voltage (VC) at 6.2A peak pulse current (IPP), and operates from –55°C to +150°C.
For engineers reviewing the SMAJ40A-13 datasheet, SMAJ40A-13 pinout, SMAJ40A-13 application, or SMAJ40A-13 equivalent, key selection criteria include clamping performance under 8.3ms surge, unidirectional polarity handling, SMA package thermal dissipation capability, and RoHS-compliant lead-free finish suitability for industrial power supply and automotive body electronics protection.
Technical Context
This TVS diode uses glass-passivated silicon junction construction to achieve fast response time (<1ps) and stable clamping during transient events such as ESD, lightning-induced surges, and inductive switching spikes. Its unidirectional configuration enables integration into polarized DC circuits without reverse conduction risk.
The device complies with IEC 61000-4-2 (ESD) and IEC 61000-4-5 (surge) immunity requirements when applied with proper PCB layout and series impedance. Clamping behavior is characterized under standardized 8.3/20μs current waveforms with 4-pulse-per-minute duty cycle limitation per JEDEC test method.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400 W - Sustains single 8.3ms half-sine surge without failure under defined thermal conditions. |
| Reverse Standoff Voltage | 40 V - Maximum continuous DC or RMS voltage before significant leakage; sets operating margin below breakdown. |
| Breakdown Voltage | 44.4–49.1 V @ 1 mA - Confirmed avalanche onset range; ensures reliable triggering above normal rail voltage. |
| Clamping Voltage | 64.5 V @ 6.2 A - Maximum voltage seen by protected circuit during specified 8.3ms surge event. |
| Peak Pulse Current | 6.2 A - Peak current handled at rated clamping voltage; defines surge energy absorption capacity. |
| Operating Temperature | –55°C to +150°C - Validated junction temperature range for automotive under-hood and industrial control environments. |
| Leakage Current | 5.0 µA @ 40 V - Low standby loss critical for battery-powered or high-impedance sensing nodes. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with UL 94V-0 flammability rating, cathode band polarity indicator, and 0.064 g typical weight. Terminals are solderable per MIL-STD-202, Method 208.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during forward conduction | Connected to ground or low-side reference in unidirectional clamp configuration. |
| Cathode | Current exit point during reverse-biased clamping | Connected to protected line; conducts avalanche current to ground when VRWM exceeded. |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated die | Enhances long-term reliability and moisture resistance vs. epoxy-passivated alternatives. |
| 400W peak pulse rating | Supports robust protection against IEC 61000-4-5 Level 3 (1kV/2Ω) surges in 24V industrial systems. |
| Fast response time | <1 ps junction response enables clamping before sensitive ICs experience overstress. |
| RoHS-compliant matte tin finish | Enables lead-free reflow assembly without whisker risk or compatibility issues. |
| SMA package thermal performance | 1.0 W steady-state dissipation at TL = 75°C supports board-level thermal management in dense layouts. |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module |
|---|---|
Use Scenario: 24V DC input channels exposed to load dump and relay coil flyback in programmable logic controllers. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input terminal and ground to clamp transients before signal conditioning amplifier. Use Value: Limits voltage to ≤64.5V during 6.2A surge, preventing damage to 30V-rated op-amps and ADC front-ends. |
Use Scenario: LIN bus node power supply rail subjected to ISO 7637-2 Pulse 1 and Pulse 2a transients. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 12V VCC rail upstream of LDO regulator and microcontroller. Use Value: Absorbs 400W surge energy while maintaining rail integrity below 65V, avoiding brownout or latch-up. |
| DC Power Supply Input Stage | Telecom Remote Power Feeding |
Use Scenario: 48V telecom power entry point vulnerable to induced surges from nearby AC mains or lightning coupling. IC Role / Device Role / Timing Role: First-line TVS in series with fuse and common-mode choke on rectified DC input. Use Value: Clamps 8.3ms surges to 64.5V within 1ps, protecting downstream MOSFETs and PWM controllers rated for 60V max. |
Use Scenario: PoE-powered remote equipment receiving 57V DC over twisted pair, subject to cable discharge events. IC Role / Device Role / Timing Role: Bidirectional-capable variant (SMAJ40CA-13) used across differential pair; unidirectional version applied on DC return path. Use Value: Maintains ≤5µA leakage at 40V, minimizing standby power loss in always-on remote units. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A-TP from Microchip | Same 40V VRWM, 64.5V VC, but rated for 450W peak pulse power and qualified to AEC-Q101. | Required for automotive safety-critical modules where AEC-Q101 qualification is mandatory. | Select when automotive qualification and higher surge margin are required; otherwise SMAJ40A-13 offers cost and supply-chain advantage. |
| P6SMB40A from ON Semiconductor | Identical electrical specs (40V VRWM, 64.5V VC, 6.2A IPP), same SMA package, but rated for 600W peak pulse power. | Preferred in high-reliability industrial designs requiring extended surge endurance beyond 400W baseline. | Choose for legacy design continuity or where 600W headroom justifies minor cost increase and longer lead times. |
Compared with SMAJ40A-13, SMAJ40A-TP adds AEC-Q101 qualification at no electrical trade-off, while P6SMB40A increases peak power margin to 600W but lacks Diodes Inc.'s optimized thermal derating curve above 75°C ambient.
Availability
SMAJ40A-13 is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive body control modules, and DC power supply input stages requiring stable component supply and RoHS-compliant manufacturing.
Supply support for SMAJ40A-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 and manufacturing operations across Asia and the Americas.
SMAJ series TVS diodes are part of Diodes' transient suppression portfolio, engineered specifically for high-energy surge immunity in harsh-environment power and signal interfaces.
FAQ
What is the maximum clamping voltage of SMAJ40A-13 and under what test condition?
The maximum clamping voltage is 64.5 V, measured at 6.2 A peak pulse current using an 8.3 ms single half-sine waveform per JEDEC standards. This value represents worst-case voltage imposed on the protected circuit during a standardized surge event and is guaranteed across the full operating temperature range.
Can SMAJ40A-13 be used in bidirectional signal line protection?
No - SMAJ40A-13 is unidirectional and contains a cathode band marking. For bidirectional protection, use SMAJ40CA-13, which omits the polarity indicator and clamps symmetrically for AC or data-line applications. Substituting the unidirectional version on bidirectional lines risks forward conduction and failure.
How does the SMA package affect thermal performance in continuous operation?
The SMA package delivers 1.0 W steady-state power dissipation at TL = 75°C, meaning it requires adequate copper area and thermal vias to maintain lead temperature below 75°C. Without sufficient PCB copper, derating is necessary - e.g., ~0.7 W at TL = 100°C per the published derating curve.
Is SMAJ40A-13 compliant with lead-free assembly processes?
Yes - SMAJ40A-13 features a matte tin lead finish compliant with RoHS Directive 2011/65/EU and supports standard Pb-free reflow profiles (peak 260°C). The device meets J-STD-020C moisture sensitivity level 1, eliminating bake requirements prior to assembly.
SMAJ40A-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):
- 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 FAQ
1.How can I place an order for SMAJ40A-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ40A-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 SMAJ40A-13 reliable?
The price and inventory of SMAJ40A-13 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 is usually 5 days.
3.What payment methods are accepted for SMAJ40A-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ40A-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ40A-13?
SMAJ40A-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ40A-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 SMAJ40A-13?
For technical support, including SMAJ40A-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ40A-13 requirements.
6.How does Aetrix verify that SMAJ40A-13 is sourced from the original manufacturer or authorized distributors?
All SMAJ40A-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 SMAJ40A-13 meets industry standards.
7.What is the process for return or replacement of SMAJ40A-13?
All SMAJ40A-13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ40A-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 SMAJ40A-13 part is unused and in its original packaging.
Return procedure for SMAJ40A-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ40A-13 Tags
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