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Alpha & Omega Semiconductor Inc. SMDJ45CA
- Part No.:
- SMDJ45CA
- Manufacturer:
- Alpha & Omega Semiconductor Inc.
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMDJ45CA.pdf
- Description:
- 1CH 45V BIDIRECTIONAL 3000W SMD
- Quantity:
- Payment:
- Shipping:
Inventory:2,655
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Product details
Overview
SMDJ45CA from Alpha & Omega Semiconductor is a bi-directional transient voltage suppressor (TVS) diode in DO-214AB (SMC) package, rated for 45 V reverse stand-off voltage (VRWM), 50–55.3 V breakdown voltage (VBR), 72.7 V maximum clamping voltage (VC) at 41.3 A peak pulse current, and 3000 W peak pulse power on 10/1000 µs waveform - deployed for surge protection in DC power rails and I/O interfaces of industrial controllers and telecom equipment.
For engineers reviewing the SMDJ45CA datasheet, pinout, applications, or equivalent options, key selection criteria include bidirectional clamping capability, low clamping ratio (VC/VBR ≈ 1.45), JEDEC-compliant DO-214AB thermal performance (RθJA = 75 °C/W), and MSL1 moisture sensitivity rating for lead-free reflow compatibility.
Technical Context
The SMDJ45CA operates as a silicon avalanche diode with glass-passivated junction, delivering sub-1 ps response time from 0 V to breakdown. Its bidirectional architecture enables symmetrical clamping across both polarities without external polarity management.
Designed for non-repetitive surge events at ≤0.01% duty cycle, it sustains 3000 W peak pulse power when mounted on 8.0 mm × 8.0 mm copper pads, with thermal resistance junction-to-lead of 15 °C/W ensuring localized heat dissipation during transient events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 45.0 V - Maximum continuous reverse operating voltage before clamping initiates. |
| VBR @ IT=1A | 50.0–55.3 V - Confirmed avalanche breakdown range under 1 mA test current; defines turn-on threshold precision. |
| VC @ IPPM | 72.7 V - Clamped voltage at 41.3 A peak pulse current; determines protected circuit's maximum overvoltage exposure. |
| PPPM (10/1000µs) | 3000 W - Peak surge energy handling capacity; supports IEC 61000-4-5 Level 4 (4 kV) compliance with appropriate impedance matching. |
| TJ max | +150 °C - Maximum junction temperature; enables operation in high-ambient industrial environments with derated power above 25 °C. |
| Polarity | Bi-directional - Symmetric clamping in both directions; eliminates need for polarity-aware board layout or external series components. |
Pinout & Package
DO-214AB (SMC J-Bend) surface-mount package with molded plastic case, matte tin lead-free plating, and cathode band marking for polarity identification (not applicable for bi-directional function). Mounting requires 8.0 mm × 8.0 mm copper pads per terminal per datasheet thermal specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode | Bi-directional avalanche terminals | No functional distinction - identical clamping behavior in either direction; color band denotes cathode only for unidirectional variants (not used in SMDJ45CA). |
Key Features
| Feature | Design Value |
|---|---|
| Fast response time | <1.0 ps - Enables clamping before sensitive downstream logic or analog circuitry experiences overvoltage stress. |
| Glass passivated junction | Enhanced reliability and stable VBR over lifetime - reduces parameter drift due to humidity or thermal cycling. |
| MSL1 rating | Compatible with standard lead-free reflow profiles up to 260 °C peak - eliminates pre-bake requirements and streamlines SMT assembly. |
| UL 94V-0 flammability | Self-extinguishing plastic housing - meets safety standards for enclosed industrial and telecom enclosures. |
Applications
| Industrial PLC I/O Protection | Telecom DC Power Input |
|---|---|
Use Scenario: Protecting 48 V DC input stage of programmable logic controller against lightning-induced surges and inductive switching transients. IC Role / Device Role / Timing Role: Primary surge shunt device placed at board edge before DC-DC converter input. Use Value: Limits transient voltage to ≤72.7 V during 3000 W surges, preventing damage to upstream EMI filters and downstream regulators. | Use Scenario: Safeguarding -48 V telecom power feed in base station line cards exposed to AC-coupled surges and hot-swap transients. IC Role / Device Role / Timing Role: Bidirectional clamping element across power rail and return, symmetrically suppressing positive and negative polarity surges. Use Value: Maintains system uptime by absorbing repetitive 10/1000 µs surges without degradation, validated for ≥1000 cycles at 0.01% duty. |
| Automotive Body Control Module | Smart Meter Power Supply |
Use Scenario: Protecting 12 V/24 V supply lines in body control modules subjected to load dump and ISO 7637-2 Pulse 5a/b. IC Role / Device Role / Timing Role: Secondary-level TVS after primary fuse and choke, providing fast-response clamping where MOVs are too slow. Use Value: Sub-1 ps response ensures clamping occurs before 12 V rail exceeds 72.7 V, preserving CAN transceivers and microcontroller I/O. | Use Scenario: Securing AC/DC adapter output in utility smart meters facing conducted surges per IEC 61000-4-5. IC Role / Device Role / Timing Role: Final-stage overvoltage clamp on regulated 3.3 V or 5 V rail feeding metrology IC and RF module. Use Value: Low leakage (≤2 µA @ 45 V) prevents battery drain in always-on metering applications while maintaining robust 3000 W surge margin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SAC45CA (Littelfuse) | Same VRWM (45 V), slightly higher VC (73.0 V), identical DO-214AB package and 3000 W rating. | Identical placement and footprint; minor clamping voltage difference has negligible impact on protected circuit margin. | Select when dual-sourcing required and Littelfuse qualification is mandated. |
| 1.5KE45CA (ON Semiconductor) | Higher RθJA (100 °C/W vs. 75 °C/W), axial DO-201 package - not surface-mount compatible. | Requires through-hole PCB redesign; unsuitable for high-density SMT layouts. | Use only in legacy through-hole designs where SMT is not feasible. |
Compared with SAC45CA and 1.5KE45CA, the SMDJ45CA offers superior thermal performance in SMT form factor, enabling higher sustained surge reliability in compact industrial modules - whereas SAC45CA is a direct footprint-compatible alternative, and 1.5KE45CA necessitates mechanical redesign.
Availability
SMDJ45CA is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and automotive electronics requiring stable component supply with full RoHS and halogen-free compliance.
Supply support for SMDJ45CA 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 MOSFETs, TVS diodes, and power ICs for high-efficiency power conversion and protection.
The SMDJxxxA/CA family was engineered for high-power, surface-mount surge immunity in space-constrained industrial and telecom systems - emphasizing low clamping ratio, MSL1 reflow readiness, and JEDEC-standard thermal performance.
FAQ
What is the clamping voltage of the SMDJ45CA at its rated peak pulse current?
The SMDJ45CA exhibits a maximum clamping voltage (VC) of 72.7 V at its rated peak pulse current (IPPM) of 41.3 A on a 10/1000 µs waveform. This value is measured per JEDEC standards and defines the upper voltage limit imposed on protected circuits during worst-case surge events. The SMDJ45CA maintains this clamping performance consistently across its operational temperature range and is validated for non-repetitive surge conditions per datasheet test conditions.
Is the SMDJ45CA suitable for bidirectional signal line protection?
Yes, the SMDJ45CA is explicitly designed as a bi-directional TVS diode, with identical electrical characteristics in both forward and reverse directions. Its symmetrical clamping behavior makes it appropriate for protecting AC-coupled data lines, RS-485 buses, or any interface where voltage transients may occur with either polarity - unlike unidirectional variants such as SMDJ45A. The SMDJ45CA achieves this without requiring external polarity configuration.
What is the thermal resistance of the SMDJ45CA, and how does it affect PCB layout?
The SMDJ45CA has a typical junction-to-ambient thermal resistance (RθJA) of 75 °C/W when mounted on 8.0 mm × 8.0 mm copper pads per terminal. This value directly impacts PCB copper area requirements: reducing pad size increases thermal resistance and lowers safe surge repetition rate. For reliable 3000 W pulse handling, the SMDJ45CA must be placed on specified copper land patterns - undersized traces or insufficient thermal vias will cause premature thermal failure during repeated surges.
Does the SMDJ45CA meet lead-free reflow requirements?
Yes, the SMDJ45CA is rated MSL1 per J-STD-020 and qualified for lead-free reflow with a maximum peak temperature of 260 °C. Its matte tin lead-free plating and UL 94V-0 compliant molding compound ensure compatibility with standard Class 3 SMT processes. No pre-baking is required, and the SMDJ45CA retains full electrical specifications post-reflow - critical for high-yield manufacturing of industrial and telecom assemblies.
How does the SMDJ45CA compare to MOV-based surge protection?
The SMDJ45CA provides faster response (<1 ps vs. ~20–50 ns for MOVs), tighter voltage tolerance, and no degradation after repeated surges - unlike MOVs which wear out. While MOVs offer higher single-event energy ratings, the SMDJ45CA delivers precise, repeatable clamping ideal for protecting sensitive semiconductors downstream of bulk filtering. In hybrid protection schemes, the SMDJ45CA often serves as the final-stage "precision clamp" complementing upstream MOV or gas discharge tube stages.
SMDJ45CA 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):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 41.3A
- 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
SMDJ45CA FAQ
1.How can I place an order for SMDJ45CA through Aetrix?
Please submit a Request for Quotation (RFQ) for SMDJ45CA 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 SMDJ45CA reliable?
The price and inventory of SMDJ45CA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMDJ45CA is usually 5 days.
3.What payment methods are accepted for SMDJ45CA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMDJ45CA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMDJ45CA?
SMDJ45CA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMDJ45CA 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 SMDJ45CA?
For technical support, including SMDJ45CA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMDJ45CA requirements.
6.How does Aetrix verify that SMDJ45CA is sourced from the original manufacturer or authorized distributors?
All SMDJ45CA 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 SMDJ45CA meets industry standards.
7.What is the process for return or replacement of SMDJ45CA?
All SMDJ45CA units undergo pre-shipment inspection (PSI). If there is an issue with SMDJ45CA, 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 SMDJ45CA part is unused and in its original packaging.
Return procedure for SMDJ45CA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMDJ45CA Tags
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