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Taiwan Semiconductor Corporation SMAJ40CA
- Part No.:
- SMAJ40CA
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ40CA.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:7,195
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Product details
Overview
SMAJ40CA from Taiwan Semiconductor is a bidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, designed for clamping fast ESD and surge transients in DC power lines. It features a 40V working stand-off voltage (VWM), 44.4–49.1V breakdown voltage (VBR @ 1mA), and clamps to ≤64.5V at 6.2A peak impulse current under 10/1000μs waveform - used in automotive body control modules and industrial DC/DC converters.
For engineers reviewing the SMAJ40CA datasheet, SMAJ40CA pinout, SMAJ40CA application, or SMAJ40CA equivalent, key selection criteria include bidirectional clamping capability, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, moisture sensitivity level 1 rating, and verified 150°C junction temperature operation without derating below 25°C ambient.
Technical Context
This bidirectional TVS diode uses a glass-passivated silicon junction to achieve sub-1ps response time from 0V to VBR(min), enabling effective suppression of ESD events per IEC 61000-4-2 (±30kV contact). Its unidirectional counterpart (SMAJ40A) shares identical VWM, VBR, and IPPM ratings but lacks symmetrical reverse conduction.
The device operates across –55°C to +150°C junction temperature range with <1μA reverse leakage at 40V, and delivers 400W peak pulse power (10/1000μs) up to 78V VWM; above 78V, pulse rating drops to 300W - a critical design constraint for 48V telecom and 60V industrial bus protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - maximum continuous reverse operating voltage before significant leakage; defines safe DC bus voltage margin |
| VBR @ IT=1mA | 44.4–49.1 V - guaranteed breakdown onset range; ensures predictable clamping initiation during transients |
| VC @ IPPM=6.2A | ≤64.5 V - maximum clamped voltage at rated 10/1000μs surge; determines protected circuit's overvoltage stress limit |
| PPPM | 400 W - peak pulse power handling (10/1000μs); supports single-event surges up to 6.2A without failure |
| IR @ VWM | <1 μA - ultra-low reverse leakage at stand-off voltage; avoids parasitic loading on sensitive 40V sensor rails |
| Junction Temp Range | –55°C to +150°C - enables deployment in under-hood automotive and high-temperature industrial enclosures |
| Package | DO-214AC (SMA) - industry-standard surface-mount outline with 0.060g mass; compatible with J-STD-002 soldering |
Pinout & Package
DO-214AC (SMA) package: molded epoxy case meeting UL 94V-0 flammability rating; matte tin-plated leads; polarity indicated by cathode band (bidirectional symmetry means both terminals function identically).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Bidirectional transient conduction path | Both terminals conduct equally in either polarity - no orientation dependency during PCB placement |
| Case | Non-electrical mechanical interface | No internal connection; serves only as thermal and mechanical anchor; no heatsinking requirement |
Key Features
| Feature | Design Value |
|---|---|
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (capacitive coupling) - essential for automotive 12V/24V systems |
| Moisture Sensitivity Level 1 | Zero floor-life limitation before reflow; eliminates baking requirements and simplifies SMT line integration |
| Fast response time | <1.0 ps from 0 V to VBR(min) - clamps before downstream ICs experience damaging voltage overshoot |
| RoHS & halogen-free | Compliant with IEC 61249-2-21 and EU RoHS Directive 2011/65/EU - meets global environmental and safety mandates |
| Steady-state power dissipation | 1 W - sufficient for continuous bias conditions without thermal runaway in ambient up to 70°C |
Applications
| Automotive Body Control Module | Industrial 48V DC/DC Converter |
|---|---|
Use Scenario: Protects LIN/CAN node power inputs against load dump and alternator ripple in vehicle door modules and seat controllers. IC Role / Device Role / Timing Role: Bidirectional clamping element placed directly at connector entry point before LDO or MCU power rail. Use Value: Limits transient excursions to ≤64.5V, preventing latch-up or gate oxide damage in 40V-rated power management ICs. |
Use Scenario: Shields primary-side MOSFET gate drivers and feedback optocouplers in isolated 48V-to-12V flyback converters. IC Role / Device Role / Timing Role: Fast-acting shunt clamp parallel to input bulk capacitor, triggered within picoseconds of surge onset. Use Value: Maintains system uptime by absorbing 400W surges without degradation - validated for >10,000 pulses per MIL-STD-750 Method 2074. |
| Smart Lighting Driver (LED Streetlamp) | Telecom Power Shelf Input |
Use Scenario: Guards constant-current LED driver ICs against lightning-induced surges on outdoor AC/DC front-end outputs. IC Role / Device Role / Timing Role: Secondary-side TVS on low-voltage DC output rail (typically 24–48V), coordinated with upstream MOVs. Use Value: Provides precise clamping at 64.5V - avoids overvoltage shutdown of PWM controllers while preserving LED string integrity. |
Use Scenario: Safeguards hot-swap controller inputs and PMBus communication lines in 48V telecom rectifier shelves. IC Role / Device Role / Timing Role: Point-of-load transient suppressor mounted adjacent to backplane connectors and ASIC power pins. Use Value: Enables compliance with GR-1089-CORE Section 4.5.2 (lightning surge) due to sub-1ps response and 64.5V clamping ceiling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40A (Taiwan Semiconductor) | Unidirectional; identical VWM, VBR, VC, and PPPM, but conducts only in reverse direction | Requires correct polarity placement; unsuitable for AC-coupled or floating-bus systems | Select SMAJ40A only when circuit topology guarantees fixed polarity and space constraints favor same footprint |
| SMBJ40CA (ON Semiconductor) | Same VWM/VBR/VC specs but in larger DO-214AA (SMB) package; 600W PPPM rating | Higher surge margin but requires 30% more PCB area; not drop-in compatible due to different pad layout | Choose SMBJ40CA when system-level surge testing exceeds 400W or thermal cycling demands higher robustness |
Compared with SMAJ40A and SMBJ40CA, the SMAJ40CA uniquely balances bidirectional protection, DO-214AC space efficiency, and ISO 7637-2 validation - making it optimal for compact automotive ECUs where polarity-agnostic clamping and MSL-1 handling are mandatory.
Availability
SMAJ40CA is available at Aetrix Electronics and suitable for automotive body electronics, industrial 48V DC/DC converters, smart lighting drivers, and telecom power shelf inputs requiring stable component supply with full traceability and lifecycle support.
Supply support for SMAJ40CA 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated analog and discrete semiconductor manufacturer headquartered in Hsinchu Science Park, Taiwan, serving automotive, industrial, and consumer markets since 1979.
The SMAJ series is part of TSC's transient voltage suppression portfolio, engineered specifically for ISO 7637-2-compliant automotive and harsh-environment industrial applications requiring high-reliability, surface-mount surge protection.
FAQ
What is the clamping voltage of SMAJ40CA at its rated peak pulse current?
The SMAJ40CA clamps to a maximum of 64.5 V when subjected to its rated peak impulse current of 6.2 A under the standard 10/1000 μs waveform. This value is measured per JEDEC test conditions and guarantees protection for downstream 40V-rated components without exceeding their absolute maximum voltage ratings. The SMAJ40CA achieves this performance consistently across its operational temperature range of –55°C to +150°C.
Is SMAJ40CA suitable for automotive applications requiring ISO 7637-2 compliance?
Yes, the SMAJ40CA is explicitly validated for ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b waveforms - covering load dump, switching transients, and capacitive coupling events common in 12V and 24V vehicle electrical systems. Its bidirectional architecture, 150°C junction rating, and MSL-1 qualification make it appropriate for engine bay and body control module deployments where SMAJ40CA must operate reliably under thermal and electrical stress.
How does SMAJ40CA differ from SMAJ40A in circuit implementation?
The SMAJ40CA is bidirectional, meaning it clamps symmetrically in both polarities and requires no orientation during placement. In contrast, SMAJ40A is unidirectional and must be installed with correct anode/cathode alignment relative to the DC rail. This makes SMAJ40CA ideal for floating or AC-coupled nodes, whereas SMAJ40A suits fixed-polarity supplies where board space allows strict orientation control - a distinction critical when routing the SMAJ40CA into legacy designs originally using SMAJ40A.
What is the maximum steady-state power dissipation rating for SMAJ40CA?
The SMAJ40CA has a steady-state power dissipation rating of 1 W at 25°C ambient temperature, derated linearly above that point per the manufacturer's thermal curve. This rating supports continuous operation in thermally managed environments such as enclosed industrial power supplies, but does not imply sustained surge handling - the 400W rating applies only to non-repetitive 10/1000μs pulses. For thermal design, the SMAJ40CA's 0.060g mass and DO-214AC footprint enable efficient PCB copper pour heat spreading.
Does SMAJ40CA meet RoHS and halogen-free requirements?
Yes, the SMAJ40CA is fully compliant with the EU RoHS Directive 2011/65/EU and certified halogen-free per IEC 61249-2-21. Its molding compound contains no brominated flame retardants, chlorine, fluorine, iodine, or bromine above threshold limits, and all terminations use matte tin plating per J-STD-002. These attributes ensure the SMAJ40CA supports environmentally regulated end equipment including automotive ECUs and industrial automation controllers.
SMAJ40CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- 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:
- DO-214AC (SMA)
SMAJ40CA FAQ
1.How can I place an order for SMAJ40CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ40CA 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 reliable?
The price and inventory of SMAJ40CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ40CA is usually 5 days.
3.What payment methods are accepted for SMAJ40CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ40CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ40CA?
SMAJ40CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ40CA 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?
For technical support, including SMAJ40CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ40CA requirements.
6.How does Aetrix verify that SMAJ40CA is sourced from the original manufacturer or authorized distributors?
All SMAJ40CA 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 meets industry standards.
7.What is the process for return or replacement of SMAJ40CA?
All SMAJ40CA units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ40CA, 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 part is unused and in its original packaging.
Return procedure for SMAJ40CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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