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Taiwan Semiconductor Corporation SMAJ40CAH
- Part No.:
- SMAJ40CAH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ40CAH.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,702
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Product details
Overview
SMAJ40CAH from Taiwan Semiconductor is a bidirectional 400W transient voltage suppressor (TVS) diode in DO-214AC (SMA) package, with 40V working stand-off voltage (VWM), 44.4–49.1V breakdown voltage (VBR), and 64.5V maximum clamping voltage (VC) at 6.2A peak impulse current - designed for automotive-grade surge protection in DC/DC converters and lighting systems.
For engineers reviewing the SMAJ40CAH datasheet, SMAJ40CAH pinout, SMAJ40CAH application, or SMAJ40CAH equivalent, this device delivers AEC-Q101 qualification, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, sub-1ps response time, and <1μA reverse leakage above 40V - critical for robust ESD and load-dump immunity in harsh-environment electronics.
Technical Context
The SMAJ40CAH is a bidirectional TVS diode optimized for unidirectional or bidirectional transient suppression without polarity dependency. Its glass-passivated junction ensures stable VBR tolerance (±5% typical), low capacitance (<100pF at 1MHz), and fast response (<1.0ps rise to VBR), enabling effective clamping of fast-rising transients like ESD and inductive switching spikes.
It operates across -55°C to +150°C junction temperature range and supports 400W peak pulse power (10/1000μs waveform) at 25°C, derating linearly above that ambient. The device meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements for high-reliability surface-mount deployment.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse operating voltage before significant leakage begins; defines safe DC bias margin. |
| VBR @ IT=1mA | 44.4–49.1 V - Breakdown threshold range; ensures reliable turn-on during overvoltage events with tight process control. |
| VC @ IPPM=6.2A | 64.5 V - Clamped voltage under 10/1000μs surge; limits downstream IC stress to safe levels. |
| PPPM | 400 W - Peak pulse power handling (10/1000μs); supports automotive load-dump and ISO 7637-2 Pulse 5a. |
| IR @ VWM | <1 μA - Ultra-low reverse leakage at rated stand-off; preserves battery life and signal integrity in always-on circuits. |
| TJ Range | -55°C to +150°C - Full automotive temperature operation; validated per AEC-Q101 stress test conditions. |
Pinout & Package
DO-214AC (SMA) surface-mount package: molded epoxy case with matte tin-plated leads, polarity indicated by cathode band; weight ≈0.060g; moisture sensitivity level (MSL) 1 per J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Cathode Band Side) | Transient return path for bidirectional clamping | Marked end serves as reference node for both polarities; enables symmetrical clamping without external polarity selection. |
| Cathode (Opposite Cathode Band) | Transient return path for bidirectional clamping | Unmarked end completes the bidirectional conduction path; no functional distinction between terminals in CAH configuration. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood and powertrain applications including temperature cycling, HTRB, and ESD testing. |
| Glass passivated junction | Ensures long-term VBR stability and low parameter drift over lifetime and thermal stress. |
| ISO 7637-2 compliance | Meets Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (line impedance coupling) requirements. |
| Fast response time | <1.0 ps from 0 V to VBR min; captures nanosecond-scale ESD and lightning-induced surges before downstream IC damage occurs. |
| Halogen-free & RoHS | Complies with IEC 61249-2-21 and EU RoHS Directive; suitable for green manufacturing and export compliance. |
Applications
| Automotive Lighting Systems | On-Board DC/DC Converters |
|---|---|
Use Scenario: LED headlamp drivers exposed to load-dump transients during alternator regulation faults. IC Role / Device Role / Timing Role: Bidirectional clamping element placed across input rails to limit voltage excursions to ≤64.5V during 12V system surges. Use Value: Prevents MOSFET gate oxide rupture and controller IC latch-up during ISO 7637-2 Pulse 5a events up to 400W. | Use Scenario: 48V-to-12V buck converter in mild-hybrid vehicles subjected to battery line noise and relay bounce. IC Role / Device Role / Timing Role: Primary transient suppressor on input side, absorbing repetitive 10/1000μs pulses from switching nodes and supply coupling. Use Value: Maintains <1μA leakage at 40V stand-off to avoid quiescent current penalty while clamping spikes within safe VIN window. |
| Industrial SMPS Inputs | Adapter Secondary-Side Protection |
Use Scenario: AC/DC front-end rectifier output in factory automation PSUs experiencing line surges and capacitor discharge transients. IC Role / Device Role / Timing Role: Standoff-rated TVS placed after bulk capacitor to clamp residual transients before PFC or main controller stage. Use Value: 44.4–49.1V VBR window aligns precisely with 48V nominal rail tolerances, ensuring early turn-on without false triggering. | Use Scenario: USB-C PD adapter secondary-side output exposed to hot-plug ESD and cable coupling events. IC Role / Device Role / Timing Role: Bidirectional protection device across VOUT/GND to suppress ±8kV contact ESD per IEC 61000-4-2 without polarity constraints. Use Value: Sub-1ps response captures ESD onset before regulator feedback loop reacts, preserving output regulation integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ40AHE3/5A (Vishay) | Identical VWM=40V, VBR=44.4–49.1V, VC=64.5V, but rated for 300W above 78V (vs. 400W flat to 78V for SMAJ40CAH). | Same AEC-Q101 and ISO 7637-2 compliance; slightly lower peak power margin below 78V clamping. | Select SMAJ40CAH when full 400W capability at 40V rail is required; choose SMAJ40AHE3/5A if Vishay supply chain preference dominates. |
| P6SMB40CA (ON Semiconductor) | VWM=40V, VBR=44.4–49.1V, VC=64.5V, but packaged in DO-214AA (SMB) - 2.5mm wider body than DO-214AC (SMA). | Same electrical performance; requires PCB pad revision due to larger footprint and 1.5mm greater width. | Choose SMAJ40CAH for space-constrained layouts where DO-214AC's 4.5 × 2.7mm outline saves board area; use P6SMB40CA only if SMB footprint already standardized. |
Compared with SMAJ40AHE3/5A and P6SMB40CA, the SMAJ40CAH offers identical clamping behavior and AEC-Q101 qualification but delivers full 400W pulse rating across its entire voltage range - unlike the Vishay part's derated power above 78V - and fits tighter layouts than the ON Semiconductor SMB variant.
Availability
SMAJ40CAH is available at Aetrix Electronics and suitable for automotive lighting systems, on-board DC/DC converters, and industrial SMPS inputs requiring stable component supply with AEC-Q101 assurance and ISO 7637-2 compliance.
Supply support for SMAJ40CAH 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, Taiwan, specializing in TVS diodes, rectifiers, MOSFETs, and power management devices.
The SMAJ series is TSC's AEC-Q101-qualified surface-mount TVS platform targeting automotive and industrial transient suppression, engineered for high reliability, low leakage, and precise clamping in space- and thermally constrained environments.
FAQ
What is the polarity configuration of SMAJ40CAH?
The SMAJ40CAH is a bidirectional TVS diode, meaning it provides symmetrical clamping for both positive and negative transients without requiring orientation during placement. Its "CAH" suffix explicitly denotes bidirectional functionality, and the DO-214AC package has no functional anode/cathode distinction - both terminals serve as interchangeable transient return paths.
Does SMAJ40CAH meet automotive qualification standards?
Yes, SMAJ40CAH is AEC-Q101 qualified and meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements for automotive electrical disturbances. It is rated for operation from -55°C to +150°C and passes JESD201 Class 2 whisker testing, making it suitable for under-hood and powertrain applications where reliability under thermal and mechanical stress is critical.
What is the maximum clamping voltage of SMAJ40CAH under surge conditions?
The SMAJ40CAH has a maximum clamping voltage (VC) of 64.5 V at 6.2 A peak impulse current (IPPM) using the standard 10/1000μs waveform. This value is guaranteed across the full operating temperature range and ensures downstream components see no more than 64.5 V during transient events, protecting sensitive controllers and MOSFETs.
How does SMAJ40CAH differ from the unidirectional SMAJ40AH?
The SMAJ40CAH is bidirectional, while SMAJ40AH is unidirectional. Both share identical VWM (40 V), VBR (44.4–49.1 V), and VC (64.5 V) specs, but SMAJ40AH conducts only in reverse bias and requires correct polarity placement. SMAJ40CAH eliminates orientation risk and simplifies layout in AC-coupled or floating-rail applications such as differential bus lines or isolated DC/DC outputs.
What packaging and reel options are available for SMAJ40CAH?
SMAJ40CAH is supplied in DO-214AC (SMA) package on 7,500-piece tape-and-reel format, compatible with standard SMT pick-and-place equipment. The device features matte tin-plated leads, meets J-STD-002 solderability requirements, and carries MSL Level 1 rating - allowing unlimited floor life without dry-pack or baking prior to reflow.
SMAJ40CAH 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:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ40CAH FAQ
1.How can I place an order for SMAJ40CAH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ40CAH 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 SMAJ40CAH reliable?
The price and inventory of SMAJ40CAH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ40CAH is usually 5 days.
3.What payment methods are accepted for SMAJ40CAH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ40CAH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ40CAH?
SMAJ40CAH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ40CAH 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 SMAJ40CAH?
For technical support, including SMAJ40CAH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ40CAH requirements.
6.How does Aetrix verify that SMAJ40CAH is sourced from the original manufacturer or authorized distributors?
All SMAJ40CAH 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 SMAJ40CAH meets industry standards.
7.What is the process for return or replacement of SMAJ40CAH?
All SMAJ40CAH units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ40CAH, 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 SMAJ40CAH part is unused and in its original packaging.
Return procedure for SMAJ40CAH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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