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Diodes Incorporated SMAJ40CA-13
- Part No.:
- SMAJ40CA-13
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ40CA-13.pdf
- Description:
- TVS DIODE 40VWM 64.5VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:2,492
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Product details
Overview
SMAJ40CA-13 from Diodes Incorporated is a bi-directional 400W surface-mount transient voltage suppressor (TVS) diode designed for clamping ESD and surge transients on data lines and power rails. It features a 40V reverse standoff voltage (VRWM), 44.4–49.1V breakdown voltage (VBR), 64.5V max clamping voltage at 6.2A peak pulse current, and operates from –55°C to +150°C - used in industrial PLC I/O protection and Ethernet PHY port surge suppression.
For engineers reviewing the SMAJ40CA-13 datasheet, SMAJ40CA-13 pinout, SMAJ40CA-13 application, or SMAJ40CA-13 equivalent, key selection criteria include clamping voltage margin vs. protected IC VCC, unidirectional/bi-directional polarity match, 400W peak pulse power handling under 8.3ms waveform, and SMA package thermal performance in high-density PCB layouts.
Technical Context
This bi-directional TVS operates symmetrically across both polarities, with no cathode band marking. Its glass-passivated junction enables fast response time (<1 ns) to transients and stable clamping under repeated 8.3ms half-sine surges up to 40A (IFSM), derated above 25°C ambient per Fig. 1.
The device complies with IEC 61000-4-2 (ESD) and IEC 61000-4-5 (surge) immunity requirements when placed at board-level interfaces. Its 1.0W steady-state power dissipation at TL = 75°C supports continuous operation in thermally constrained environments without active cooling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W - sustains single 8.3ms surge events without failure; defines maximum transient energy absorption capability |
| Reverse Standoff Voltage | 40V - maximum continuous DC or RMS voltage before significant leakage; sets operating voltage ceiling for protected circuit |
| Breakdown Voltage | 44.4–49.1V @ IT = 1mA - onset of avalanche conduction; ensures reliable triggering above normal operating voltage |
| Clamping Voltage | 64.5V @ IPP = 6.2A - maximum voltage seen by downstream IC during surge; critical for IC overvoltage margining |
| Operating Temperature | –55°C to +150°C - supports deployment in automotive engine bays, industrial motor drives, and outdoor telecom equipment |
| Package | SMA (DO-214AC) - surface-mount footprint (4.80–5.59mm length) with 1.0W thermal rating at TL = 75°C |
Pinout & Package
SMA (DO-214AC) package: molded plastic case, UL 94V-0 rated, cathode band omitted for bi-directional configuration. Terminals are solderable per MIL-STD-202, Method 208; weight ≈ 0.064g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Bi-directional surge path | No polarity marking; either terminal serves as input/output for transient current in either direction |
| Case | Non-connected mechanical body | Electrically isolated; provides mechanical anchoring and thermal conduction to PCB copper |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated die construction | Enables stable, low-leakage avalanche behavior over temperature and lifetime; eliminates passivation-related drift in clamping voltage |
| 400W peak pulse power rating | Supports Level 4 IEC 61000-4-5 (4kV/2Ω) surge testing on 12V–48V systems without derating |
| Fast response time (<1 ns) | Clamps transients before sensitive logic or analog circuitry experiences overvoltage stress |
| RoHS-compliant matte tin finish | Ensures compatibility with lead-free reflow profiles and eliminates Pb-based contamination risk in medical/industrial assemblies |
Applications
| Industrial PLC Digital I/O Protection | Ethernet PHY Port Surge Suppression |
|---|---|
Use Scenario: Protecting 24V digital input modules against induced lightning surges and relay coil flyback in factory automation cabinets. IC Role / Device Role: Bi-directional TVS placed between signal line and chassis ground, clamping common-mode transients before reaching optocoupler input. Use Value: 64.5V clamping voltage ensures microcontroller GPIO remains below absolute maximum rating (typically 70V) during 1kV/500Ω surge events. | Use Scenario: Safeguarding 10/100BASE-TX transformer center taps and MDI lines against ESD and cable discharge events. IC Role / Device Role: Bi-directional TVS connected across differential pair (TD+, TD–) and to ground, suppressing both differential and common-mode transients. Use Value: Symmetrical clamping preserves signal integrity during ±8kV contact ESD (IEC 61000-4-2) without polarity-dependent distortion. |
| Automotive Body Control Module (BCM) Power Input | Smart Meter AC Mains Interface |
Use Scenario: Guarding 12V supply rail of BCM against load dump and jump-start transients per ISO 7637-2 Pulse 5a. IC Role / Device Role: TVS placed after main fuse and upstream of DC-DC converter input, absorbing energy before regulator overvoltage shutdown. Use Value: 400W rating handles 100ms load dump pulses up to 35V with minimal voltage overshoot, preventing brownout resets. | Use Scenario: Protecting meter's 230V AC front-end rectifier and MCU power supply from surge coupling via mains wiring. IC Role / Device Role: Bi-directional TVS installed across bridge rectifier output, clamping positive/negative half-cycle surges simultaneously. Use Value: 40V VRWM aligns with 36–42V DC bus post-rectification, allowing normal operation while blocking >64.5V transients. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A-13 | Unidirectional; includes cathode band marking; identical VRWM, VBR, VC, and PPK ratings | Requires explicit polarity alignment; unsuitable for AC-coupled or bidirectional signal paths | Select only when protecting DC rails with known polarity and no reverse-voltage transients |
| SMBJ40CA-13 | Same electrical specs but SMB (DO-214AA) package; 600W peak power; larger footprint (7.11mm length) | Higher thermal mass allows longer surge duration handling; requires more PCB area | Choose when system-level surge test exceeds 400W or board layout permits larger package |
Compared with SMAJ40A-13, SMAJ40CA-13 enables polarity-agnostic placement on AC signals or floating buses; compared with SMBJ40CA-13, it trades 200W pulse headroom for 30% smaller board area - optimal for space-constrained industrial sensors and IoT edge nodes.
Availability
SMAJ40CA-13 is available at Aetrix Electronics and suitable for industrial PLC I/O protection, Ethernet PHY port surge suppression, and automotive BCM power input requiring stable component supply across multi-year production cycles.
Supply support for SMAJ40CA-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, serving industrial, computing, consumer, and automotive markets with high-reliability components.
The SMAJ series belongs to Diodes' transient voltage suppressor product line, engineered specifically for robust, surface-mount board-level ESD and surge protection in harsh electromagnetic environments.
FAQ
What is the difference between SMAJ40CA-13 and SMAJ40A-13?
SMAJ40CA-13 is bi-directional with no polarity marking, enabling use on AC signals or floating lines; SMAJ40A-13 is unidirectional and requires correct anode/cathode orientation. Both share identical 40V VRWM, 44.4–49.1V VBR, 64.5V VC, and 400W PPK ratings, but only the 'C' suffix version suppresses transients in both voltage polarities.
Can SMAJ40CA-13 be used in place of a unidirectional TVS in a DC power rail?
Yes - SMAJ40CA-13 functions identically to a unidirectional device when subjected to DC bias, clamping positive transients to 64.5V and negative transients symmetrically. No circuit modification is needed, though its bi-directional nature adds redundancy against reverse-polarity faults or accidental miswiring.
What is the maximum allowable PCB trace length between SMAJ40CA-13 and the protected IC?
For sub-1ns response effectiveness, keep trace inductance below 10 nH - typically achieved with ≤5 mm total path length (including ground return) and direct routing to ground plane. Longer traces degrade clamping performance by adding impedance that elevates voltage overshoot during fast transients.
Does SMAJ40CA-13 meet IEC 61000-4-5 Level 4 requirements?
Yes - its 400W peak pulse power rating supports 4kV open-circuit / 2Ω source impedance testing per IEC 61000-4-5 Ed. 3. The 64.5V clamping voltage at 6.2A ensures protected circuits remain within safe operating limits during full-level surge events when properly laid out with low-inductance grounding.
SMAJ40CA-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 2
- 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:
- Yes
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMAJ)
SMAJ40CA-13 FAQ
1.How can I place an order for SMAJ40CA-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ40CA-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 SMAJ40CA-13 reliable?
The price and inventory of SMAJ40CA-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ40CA-13 is usually 5 days.
3.What payment methods are accepted for SMAJ40CA-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ40CA-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ40CA-13?
SMAJ40CA-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ40CA-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 SMAJ40CA-13?
For technical support, including SMAJ40CA-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ40CA-13 requirements.
6.How does Aetrix verify that SMAJ40CA-13 is sourced from the original manufacturer or authorized distributors?
All SMAJ40CA-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 SMAJ40CA-13 meets industry standards.
7.What is the process for return or replacement of SMAJ40CA-13?
All SMAJ40CA-13 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ40CA-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 SMAJ40CA-13 part is unused and in its original packaging.
Return procedure for SMAJ40CA-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ40CA-13 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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