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Taiwan Semiconductor Corporation SMDJ40A
- Part No.:
- SMDJ40A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMDJ40A.pdf
- Description:
- TVS DIODE 40VWM 64.5VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:2,318
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Product details
Overview
SMDJ40A from Taiwan Semiconductor is a unidirectional 3000W surface-mount transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, with 44.4V minimum breakdown voltage (VBR), 40V working stand-off voltage (VWM), and 64.5V maximum clamping voltage (VC) at 46.5A peak pulse current. It protects power rails and I/O lines in industrial motor drives, telecom power supplies, and automotive ECUs against ISO 7637-2 Pulse 1/2a/2b/3a/3b transients.
For engineers reviewing the SMDJ40A datasheet, SMDJ40A pinout, SMDJ40A application, or SMDJ40A equivalent, this page delivers verified electrical parameters, thermal resistance (RθJA = 75°C/W), polarity marking, JEDEC-compliant moisture sensitivity (Level 1), and real-world clamping performance under 10/1000µs surge waveforms.
Technical Context
The SMDJ40A operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its 44.4–49.1V breakdown range at 1mA test current. Its glass-passivated junction ensures stable VBR tolerance and fast response (<1.0ps), enabling reliable suppression of ESD and load-switching spikes before downstream ICs are damaged.
Designed for surface-mount automation, it features matte tin-plated leads compliant with J-STD-002 solderability and JESD 201 Class 2 whisker resistance. With a 175°C max junction temperature and -55°C to +175°C operating range, it supports high-reliability deployments in thermally demanding environments without derating below 25°C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 40 V - Maximum continuous reverse voltage the device blocks without leakage exceeding 1 µA |
| VBR @ IT=1mA | 44.4–49.1 V - Confirmed avalanche onset range; ensures predictable turn-on before system overvoltage damage |
| VC @ IPPM=46.5A | 64.5 V - Clamped voltage during 10/1000µs surge; defines worst-case stress on protected ICs |
| PPK | 3000 W - Peak pulse power handling per single non-repetitive event, per Fig.5 waveform |
| RθJA | 75 °C/W - Junction-to-ambient thermal resistance; determines required PCB copper area for sustained power dissipation |
| Junction Temp Range | -55°C to +175°C - Enables operation in under-hood automotive or industrial power converter environments |
Pinout & Package
Package: DO-214AB (SMC), molded epoxy case meeting UL 94V-0, with cathode band marking for unidirectional polarity. Weight: 0.290g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional configuration |
| Cathode (marked band) | Avalanche clamping terminal | Connected to protected line (e.g., 48V rail); conducts surge current to anode when VREV > VBR |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR over lifetime and immunity to humidity-induced parameter drift |
| ISO 7637-2 compliance | Validated for Pulse 1 (inductive load dump), Pulse 2a/2b (switching transients), and Pulse 3a/3b (line capacitance discharge) |
| Moisture sensitivity Level 1 | Zero bake requirement before reflow; compatible with standard SMT assembly without dry-pack handling |
| Fast response time | <1.0 ps - Limits voltage overshoot during nanosecond-scale ESD events (IEC 61000-4-2) |
Applications
| Industrial Motor Drives | Telecom Power Supplies |
|---|---|
Use Scenario: Protection of gate drivers and feedback sensing lines against inductive kickback from IGBT/MOSFET switching. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed across DC bus or signal inputs to limit transient voltage to ≤64.5V. Use Value: Prevents latch-up or permanent damage to isolated error amplifiers and PWM controllers during 3000W surge events. | Use Scenario: Input-stage surge protection on 48V telecom rectifier outputs exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Primary clamping device shunting ISO 7637-2 Pulse 1 energy (12V–100V, 40ms) to ground. Use Value: Maintains output regulation integrity by holding downstream DC-DC converter input below 64.5V during 46.5A peak pulses. |
| Automotive Engine Control Units | Industrial PLC I/O Modules |
Use Scenario: CAN bus power rail protection in ECU modules subjected to battery disconnect/load dump transients. IC Role / Device Role / Timing Role: Standoff-rated TVS (VWM = 40V) placed between 12V/24V supply and ground to absorb Pulse 2b (100V, 100ms). Use Value: Guarantees microcontroller reset circuitry remains functional after repeated 3000W transient exposure. | Use Scenario: Digital input protection in programmable logic controllers interfacing with 24V field sensors. IC Role / Device Role / Timing Role: Bidirectional-capable variant not used; SMDJ40A provides unidirectional clamping from sensor line to 24V rail. Use Value: Eliminates need for external series resistors by clamping induced transients before they reach optocoupler input stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SAC40 | Same 40V VWM, but lower PPK = 1500W; VC = 69.4V @ 21.6A | Not suitable for ISO 7637-2 Pulse 1 (requires ≥3000W rating); limited to lower-energy ESD-only use | Select only if system surge energy is confirmed ≤1500W and clamping voltage margin allows 69.4V |
| 1.5KE40A | Through-hole TO-218 package; identical VWM/VBR/VC, but RθJA = 10°C/W higher | Requires PCB through-hole layout; unsuitable for high-density SMT designs or automated placement | Choose only for legacy through-hole systems where rework or thermal mass outweighs SMT advantages |
Compared with SAC40 and 1.5KE40A, the SMDJ40A delivers full 3000W surge capability in a compact DO-214AB footprint with industry-leading thermal resistance (75°C/W), making it optimal for space-constrained, high-power automotive and industrial applications requiring automated assembly.
Availability
SMDJ40A is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, and automotive engine control units requiring stable component supply and full ISO 7637-2 compliance.
Supply support for SMDJ40A 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 power management, protection, and signal conditioning devices.
The SMDJ series was developed specifically for high-energy transient suppression in automotive and industrial power systems, emphasizing robustness under repetitive surge stress and compatibility with automated SMT manufacturing.
FAQ
What is the maximum clamping voltage of the SMDJ40A under a 10/1000µs surge?
The SMDJ40A has a maximum clamping voltage (VC) of 64.5 V when subjected to a 46.5 A peak pulse current with a 10/1000µs waveform. This value is measured per standard test conditions (TA = 25°C) and defines the upper voltage limit imposed on protected circuitry during worst-case transient events. The SMDJ40A maintains this clamping performance consistently across its rated operating temperature range.
Is the SMDJ40A suitable for bidirectional transient suppression?
No, the SMDJ40A is a unidirectional TVS diode and is not rated for bidirectional operation. For bidirectional protection at 40V standoff, the SMDJ40CA variant must be used. The SMDJ40A's cathode band marking and forward voltage specification (VF = 3.5 V @ 100 A) confirm its unidirectional design; applying reverse surge without proper polarity alignment will result in failure.
What is the moisture sensitivity level (MSL) of the SMDJ40A and what does it mean for assembly?
The SMDJ40A has a moisture sensitivity level (MSL) of Level 1 per J-STD-020, meaning it may be stored indefinitely at ≤30°C/60% RH without baking prior to reflow soldering. This eliminates dry-pack requirements and floor-life tracking, simplifying SMT line integration and reducing handling overhead for high-volume production of boards using the SMDJ40A.
How does the SMDJ40A meet ISO 7637-2 requirements?
The SMDJ40A is explicitly validated to meet ISO 7637-2 for Pulses 1 (inductive load dump), 2a/2b (supply disconnection and switching transients), and 3a/3b (capacitive coupling). Its 3000W peak power rating, 64.5V clamping voltage, and sub-1ps response time ensure compliance across all specified pulse shapes and amplitudes without external circuit modifications. The SMDJ40A data sheet cites this compliance directly in its FEATURES section.
What is the thermal resistance from junction to ambient (RθJA) for the SMDJ40A, and how does it affect PCB layout?
The SMDJ40A has a junction-to-ambient thermal resistance (RθJA) of 75°C/W under standard JEDEC test conditions. This value guides minimum copper pour area needed on the PCB: for example, dissipating 6.5W steady-state power requires at least ~2500 mm² of 2-oz copper connected to both terminals. Layouts must avoid thermal isolation-especially under the body-to prevent junction temperatures exceeding 175°C during surge events.
SMDJ40A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-214AB, SMC
- Series:
- SMDJ
- 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):
- 46.5A
- Power - Peak Pulse:
- 3000W (3kW)
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMC)
SMDJ40A FAQ
1.How can I place an order for SMDJ40A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMDJ40A 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 SMDJ40A reliable?
The price and inventory of SMDJ40A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMDJ40A is usually 5 days.
3.What payment methods are accepted for SMDJ40A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMDJ40A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMDJ40A?
SMDJ40A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMDJ40A 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 SMDJ40A?
For technical support, including SMDJ40A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMDJ40A requirements.
6.How does Aetrix verify that SMDJ40A is sourced from the original manufacturer or authorized distributors?
All SMDJ40A 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 SMDJ40A meets industry standards.
7.What is the process for return or replacement of SMDJ40A?
All SMDJ40A units undergo pre-shipment inspection (PSI). If there is an issue with SMDJ40A, 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 SMDJ40A part is unused and in its original packaging.
Return procedure for SMDJ40A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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