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Alpha & Omega Semiconductor Inc. SMDJ40CA
- Part No.:
- SMDJ40CA
- Manufacturer:
- Alpha & Omega Semiconductor Inc.
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMDJ40CA.pdf
- Description:
- 1CH 40V BIDIRECTIONAL 3000W SMD
- Quantity:
- Payment:
- Shipping:
Inventory:8,457
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Product details
Overview
SMDJ40CA from Alpha & Omega Semiconductor is a bi-directional transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, rated for 40 V reverse stand-off voltage (VRWM), 44.4–49.1 V breakdown voltage (VBR), 64.5 V maximum clamping voltage (VC) at 46.6 A peak pulse current, and 3000 W peak pulse power on 10/1000 µs waveform - used to protect DC power rails and I/O lines in industrial motor drives and telecom power supplies.
For engineers reviewing the SMDJ40CA datasheet, pinout, applications, or equivalent options, key selection criteria include bidirectional clamping capability, low thermal resistance (RθJL = 15 °C/W), JEDEC-compliant DO-214AB surface-mount footprint, and compliance with MSL Level 1 reflow (260 °C peak).
Technical Context
The SMDJ40CA operates as a bi-directional avalanche diode, providing symmetrical clamping in both polarities without external polarity biasing. Its glass-passivated junction ensures stable VBR tolerance (±5%) and low temperature coefficient (0.1% × VBR per °C ΔT), enabling predictable overvoltage response across –55 °C to +150 °C operating range.
Designed for non-repetitive surge suppression, it delivers sub-1 ps response time from 0 V to breakdown and supports 0.01% duty cycle operation when mounted on 8.0 mm × 8.0 mm copper pads - meeting IEC 61000-4-5 surge immunity requirements for Class 3–4 systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 40.0 V - Maximum continuous reverse operating voltage before clamping initiates |
| VBR @ IT=1A | 44.4–49.1 V - Verified avalanche breakdown threshold under 1 mA test current |
| VC @ IPPM | 64.5 V - Clamped voltage at 46.6 A peak pulse current, defining worst-case protected-line voltage |
| PPPM (10/1000µs) | 3000 W - Peak surge energy handling capacity on standard lightning-surge waveform |
| TJ max | +150 °C - Maximum junction temperature enabling operation in high-ambient industrial environments |
| RθJL | 15 °C/W - Low junction-to-lead thermal resistance supporting high-power pulse dissipation |
| IR @ VRWM | 2.0 µA - Reverse leakage confirming minimal standby power loss in battery-backed systems |
Pinout & Package
DO-214AB (SMC J-Bend) package: surface-mount, low-profile, matte tin lead-free terminations, UL 94V-0 flammability rating, and built-in strain relief. Cathode identification via color band applies only to unidirectional variants; SMDJ40CA is bi-directional and lacks polarity marking.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bi-directional avalanche terminals | No functional polarity - either terminal serves as anode or cathode depending on transient polarity |
| Case | Non-electrical mechanical body | Plastic molded case provides strain relief and meets IPC/JEDEC moisture sensitivity level MSL1 |
Key Features
| Feature | Design Value |
|---|---|
| Glass-passivated junction | Ensures stable VBR over temperature and lifetime, minimizing parameter drift in harsh environments |
| Sub-1 ps response time | Clamps transients before sensitive downstream ICs experience overvoltage stress |
| MSL1 reflow compatibility | Supports standard lead-free reflow profiles up to 260 °C peak without delamination or performance shift |
| UL 94V-0 plastic housing | Meets fire-safety requirements for enclosed industrial and telecom equipment enclosures |
| Strain-relieved leads | Reduces mechanical stress at solder joints during thermal cycling or board flexure |
Applications
| Industrial Motor Drives | Telecom Power Supplies |
|---|---|
Use Scenario: Protection of 48 V DC bus against inductive switching spikes and lightning-induced surges in variable-frequency drives. IC Role / Device Role / Timing Role: Bi-directional TVS device clamping both positive and negative transients on power rail. Use Value: Limits rail voltage to ≤64.5 V during 3000 W surges, preventing MOSFET gate oxide failure and controller latch-up. | Use Scenario: Input-stage surge protection for AC/DC front-end modules in base station power systems. IC Role / Device Role / Timing Role: Primary-level transient suppressor placed ahead of bridge rectifier and bulk capacitor. Use Value: Absorbs 10/1000 µs surges per IEC 61000-4-5 Level 4 without degrading after repeated events. |
| Automotive Body Control Modules | Industrial PLC I/O Cards |
Use Scenario: CAN bus power line protection in 12 V/24 V vehicle subsystems exposed to load-dump and jump-start transients. IC Role / Device Role / Timing Role: Bidirectional clamping element on VBAT-supplied microcontroller power domain. Use Value: Withstands 3000 W pulses while maintaining <2 µA leakage at 40 V, preserving low-power sleep mode integrity. | Use Scenario: Digital input protection on 24 V discrete I/O channels subject to field-wiring ESD and inductive kickback. IC Role / Device Role / Timing Role: Frontline TVS on each channel's signal path before optocoupler or buffer IC. Use Value: Clamps transients to 64.5 V within 1 ps, ensuring downstream logic remains within absolute maximum ratings. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SAC40CA (Littelfuse) | Same DO-214AB package, identical VRWM (40 V), but higher VC = 67.0 V at 44.5 A | Marginally lower clamping performance; suitable where layout allows slightly higher protected-rail voltage | Select when sourcing diversification is required and 2.5 V higher clamping is acceptable |
| SMCJ40CA (ON Semiconductor) | Identical electrical specs (VRWM = 40 V, VBR = 44.4–49.1 V, VC = 64.5 V), same DO-214AB package, RoHS-compliant | No functional difference; validated drop-in replacement per manufacturer cross-reference | Preferred for legacy ON-design ecosystems or dual-sourcing programs requiring identical qualification data |
Compared with SMDJ40CA, SAC40CA offers equivalent surge rating but trades 2.5 V higher clamping for broader vendor availability, while SMCJ40CA delivers identical protection performance and is qualified as a direct drop-in alternative in ON Semiconductor reference designs.
Availability
SMDJ40CA is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, and automotive body control modules requiring stable component supply and long-term production continuity.
Supply support for SMDJ40CA 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
Alpha & Omega Semiconductor (AOS) is a fabless power semiconductor company specializing in high-efficiency MOSFETs, TVS diodes, and power ICs for industrial, computing, and consumer markets.
The SMDJ series is part of AOS' transient protection portfolio, engineered specifically for high-energy 10/1000 µs surge immunity in space-constrained surface-mount applications.
FAQ
What is the clamping voltage of the SMDJ40CA under maximum surge conditions?
The SMDJ40CA exhibits a maximum clamping voltage (VC) of 64.5 V when subjected to its rated peak pulse current of 46.6 A on a 10/1000 µs waveform. This value is measured per JEDEC standards and defines the upper voltage limit imposed on protected circuitry during transient events - critical for ensuring downstream components remain within their absolute maximum ratings.
Is the SMDJ40CA unidirectional or bidirectional, and how does that affect PCB layout?
The SMDJ40CA is a bi-directional TVS diode, meaning it clamps transients of either polarity symmetrically without requiring orientation during placement. Unlike unidirectional variants (e.g., SMDJ40A), it has no cathode band and may be mounted in either direction - simplifying layout, eliminating polarity-check steps in automated assembly, and enabling use in AC-coupled or floating-rail applications.
Does the SMDJ40CA meet lead-free reflow requirements for modern manufacturing?
Yes, the SMDJ40CA is qualified to MSL Level 1 per J-STD-020 and supports lead-free reflow profiles with a maximum peak temperature of 260 °C. Its matte tin lead-free plating and glass-passivated junction ensure reliability through multiple reflow cycles without parametric shift or intermetallic degradation.
What is the thermal resistance specification for the SMDJ40CA, and why does it matter?
The SMDJ40CA has a typical junction-to-lead thermal resistance (RθJL) of 15 °C/W, measured with 8.0 mm × 8.0 mm copper pads per terminal. This low value enables efficient heat transfer from the silicon junction to the PCB during high-energy surges, directly influencing safe repetition rate and long-term reliability under repeated transient stress.
How does the SMDJ40CA compare to the SMDJ40A in terms of electrical behavior?
The SMDJ40CA is the bi-directional version of the SMDJ40A unidirectional TVS. Both share identical VRWM (40 V), VBR (44.4–49.1 V), and VC (64.5 V) ratings, but SMDJ40A requires correct cathode orientation and only clamps positive transients relative to its marked cathode, whereas SMDJ40CA protects against surges of either polarity without orientation dependency.
SMDJ40CA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Alpha & Omega Semiconductor Inc.
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- 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):
- 46.6A
- Power - Peak Pulse:
- 3000W (3kW)
- 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-214AB
SMDJ40CA FAQ
1.How can I place an order for SMDJ40CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMDJ40CA 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 SMDJ40CA reliable?
The price and inventory of SMDJ40CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMDJ40CA is usually 5 days.
3.What payment methods are accepted for SMDJ40CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMDJ40CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMDJ40CA?
SMDJ40CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMDJ40CA 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 SMDJ40CA?
For technical support, including SMDJ40CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMDJ40CA requirements.
6.How does Aetrix verify that SMDJ40CA is sourced from the original manufacturer or authorized distributors?
All SMDJ40CA 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 SMDJ40CA meets industry standards.
7.What is the process for return or replacement of SMDJ40CA?
All SMDJ40CA units undergo pre-shipment inspection (PSI). If there is an issue with SMDJ40CA, 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 SMDJ40CA part is unused and in its original packaging.
Return procedure for SMDJ40CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMDJ40CA Tags
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