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Alpha & Omega Semiconductor Inc. SMDJ45A
- Part No.:
- SMDJ45A
- Manufacturer:
- Alpha & Omega Semiconductor Inc.
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMDJ45A.pdf
- Description:
- 1CH 45V UNIDIRECTIONAL 3000W SMD
- Quantity:
- Payment:
- Shipping:
Inventory:8,173
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Product details
Overview
SMDJ45A from Alpha & Omega Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for high-energy surge protection in DC power lines and signal interfaces. It features a 45 V reverse standoff voltage (VRWM), 50–55.3 V breakdown range (VBR @ 1 mA), 72.7 V maximum clamping voltage at 41.3 A peak pulse current, and 3000 W peak pulse power rating on 10/1000 µs waveform - deployed in industrial motor drives to protect IGBT gate drivers from inductive switching transients.
For engineers reviewing the SMDJ45A datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin vs. protected IC's absolute maximum rating, thermal resistance (RθJL = 15 °C/W), unidirectional polarity confirmation, and DO-214AB package compatibility with automated SMT placement and reflow profiles up to 260 °C.
Technical Context
The SMDJ45A operates as a silicon avalanche diode that enters controlled breakdown when transient voltage exceeds its VBR threshold, diverting surge current away from downstream circuitry. Its glass-passivated junction ensures stable leakage (<2 µA @ VRWM) and long-term reliability under repeated 0.01% duty-cycle surges.
Designed for single-polarity DC rail protection, it exhibits sub-1 ps response time from 0 V to BV and meets J-STD-020 MSL Level 1 - enabling robust handling of ESD (IEC 61000-4-2), EFT (IEC 61000-4-4), and lightning-induced surges (IEC 61000-4-5) without degradation under specified thermal derating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 45 V - Maximum continuous reverse operating voltage before clamping begins; sets upper limit for protected line voltage. |
| VBR @ IT=1 mA | 50.0–55.3 V - Confirmed avalanche onset range; defines minimum overvoltage threshold for reliable triggering. |
| Vc @ IPPM | 72.7 V - Clamped voltage at 41.3 A peak pulse; must remain below protected device's absolute max rating. |
| PPPM (10/1000 µs) | 3000 W - Peak surge energy absorption capacity; determines survivability against high-energy transients. |
| TJ max | +150 °C - Maximum junction temperature; constrains thermal design when mounted on 8 mm × 8 mm copper pads. |
| RθJL | 15 °C/W - Junction-to-lead thermal resistance; enables accurate power dissipation modeling during surge events. |
| Polarity | Unidirectional - Cathode-banded configuration; requires correct orientation in series with positive rail. |
Pinout & Package
DO-214AB (SMC J-Bend) surface-mount package: molded plastic case with matte tin lead-free plating, JEDEC-compliant outline, and cathode band marking for polarity identification. Mounting requires 8.0 mm × 8.0 mm copper pads per terminal per datasheet thermal spec.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference node | Connected to ground or low-voltage return path; completes clamping loop during surge. |
| Cathode | High-side surge input | Connected to protected line (e.g., +48 V DC bus); carries full IPPM during clamping event. |
Key Features
| Feature | Design Value |
|---|---|
| Fast response time | <1.0 ps - Enables suppression before sensitive logic or analog circuits experience overvoltage stress. |
| Glass-passivated junction | Stable VBR tolerance and low IR drift over temperature and lifetime - critical for long-term field reliability. |
| MSL Level 1 rating | Compatible with standard SMT reflow up to 260 °C peak - eliminates pre-baking requirements and supports high-yield assembly. |
| Strain relief construction | Reduces mechanical stress at lead-to-body interface during board flex or thermal cycling - improves solder joint integrity. |
| UL 94V-0 flammability | Self-extinguishing plastic housing - satisfies safety standards for enclosed industrial and telecom equipment. |
Applications
| Industrial Motor Drives | Telecom Power Supplies |
|---|---|
Use Scenario: Protection of gate driver ICs and bootstrap circuits against inductive kickback from IGBTs in variable-frequency drives. IC Role / Device Role / Timing Role: Primary clamping element placed between gate resistor and driver output to shunt transient energy to ground. Use Value: Limits gate-source voltage to ≤72.7 V during 3 kA-equivalent surges, preventing driver latch-up or oxide rupture. | Use Scenario: Input-stage surge suppression on -48 V DC distribution boards in central office and remote radio units. IC Role / Device Role / Timing Role: First-line defense against lightning-induced common-mode transients coupled onto telecom power rails. Use Value: Absorbs 3000 W pulses without failure, maintaining system uptime during Category 4 (4 kV/2 kA) IEC 61000-4-5 tests. |
| Automotive Body Control Modules | Renewable Energy Inverters |
Use Scenario: Load-dump protection on 12 V/24 V battery-fed microcontroller power inputs in BCMs. IC Role / Device Role / Timing Role: Unidirectional TVS placed directly at MCU VDD pin to clamp ISO 7637-2 Pulse 5a/b transients. Use Value: Withstands 120 V/300 ms load dump events while holding clamped voltage below 75 V - within MCU's 80 V abs max rating. | Use Scenario: DC-link overvoltage suppression in solar string inverters exposed to grid-switching transients. IC Role / Device Role / Timing Role: Parallel-connected TVS across 600 V DC bus to clamp fast-rising spikes from contactor bounce or grid faults. Use Value: Delivers 3000 W peak power handling with 15 °C/W thermal resistance - enabling compact heatsinkless layout in space-constrained enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SAC45 | Same VRWM (45 V), lower PPPM (1500 W), higher Vc (77 V @ 20 A), DO-214AB package | Lower surge energy handling; suitable only for lighter-duty ESD/EFT, not lightning-level threats | Select when cost sensitivity outweighs need for 3000 W rating and tighter clamping. |
| 1.5KE45A | Through-hole DO-15 package, identical electrical specs (VRWM=45 V, VBR=50–55.3 V, Vc=72.7 V), same 3000 W rating | Requires manual or wave-solder assembly; incompatible with fully SMT production lines | Choose only if legacy through-hole design or rework constraints prohibit surface-mount adoption. |
Compared with SAC45 and 1.5KE45A, the SMDJ45A uniquely combines 3000 W surge capability, sub-1 ps response, and DO-214AB SMT compatibility - making it optimal for high-reliability, high-volume industrial and telecom systems where board space, thermal performance, and automated assembly are critical.
Availability
SMDJ45A is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, and automotive body control modules requiring stable component supply, consistent parametric performance, and RoHS-compliant green packaging.
Supply support for SMDJ45A 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 SMDJxxxA series was engineered specifically for high-power, surface-mount transient suppression in harsh environments - targeting applications demanding >3000 W surge immunity, MSL1 reflow compatibility, and stable clamping under thermal stress.
FAQ
What is the maximum clamping voltage of the SMDJ45A under rated surge conditions?
The SMDJ45A has a maximum clamping voltage (VC) of 72.7 V when subjected to its rated peak pulse current of 41.3 A on a 10/1000 µs waveform. This value is measured per JEDEC standards and ensures the protected circuit remains below critical overvoltage thresholds during transient events. The SMDJ45A maintains this clamping performance consistently across its operating temperature range of –55 °C to +150 °C.
Is the SMDJ45A suitable for bidirectional surge protection?
No, the SMDJ45A is a unidirectional TVS diode, indicated by the "A" suffix and cathode band marking. For bidirectional operation, the SMDJ45CA variant must be used - it provides symmetrical clamping in both polarities. Using SMDJ45A in reverse-biased configurations risks permanent damage due to lack of reverse conduction capability.
What is the thermal resistance specification for the SMDJ45A, and how does it impact layout design?
The SMDJ45A has a typical junction-to-lead thermal resistance (RθJL) of 15 °C/W and junction-to-ambient (RθJA) of 75 °C/W when mounted on 8.0 mm × 8.0 mm copper pads. This means effective heat dissipation requires adherence to the specified pad geometry; reducing pad size increases thermal impedance and may cause premature thermal runaway during repetitive surges. The SMDJ45A's RθJL enables direct thermal coupling to PCB ground planes for enhanced surge endurance.
Does the SMDJ45A meet lead-free and RoHS compliance requirements?
Yes, the SMDJ45A is a certified AOS Green Product: lead-free, RoHS compliant, and halogen-free per IEC 61249-2-21. Its matte tin lead finish meets J-STD-020 MSL Level 1 moisture sensitivity requirements and supports peak reflow temperatures up to 260 °C. This compliance is documented in AOS' official Green Policy and verified via material declarations for the SMDJ45A part number.
How does the SMDJ45A compare to standard 1.5KE series TVS diodes in terms of mounting and performance?
The SMDJ45A matches the 1.5KE45A's core electrical specs - including 45 V VRWM, 50–55.3 V VBR, and 72.7 V Vc - but uses a DO-214AB surface-mount package instead of DO-15 through-hole. This enables automated pick-and-place assembly, higher board density, and improved high-frequency surge response due to lower parasitic inductance. The SMDJ45A thus delivers identical protection performance in a modern SMT-optimized form factor.
SMDJ45A 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:
- 1
- Bidirectional Channels:
- -
- 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
SMDJ45A FAQ
1.How can I place an order for SMDJ45A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMDJ45A 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 SMDJ45A reliable?
The price and inventory of SMDJ45A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMDJ45A is usually 5 days.
3.What payment methods are accepted for SMDJ45A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMDJ45A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMDJ45A?
SMDJ45A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMDJ45A 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 SMDJ45A?
For technical support, including SMDJ45A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMDJ45A requirements.
6.How does Aetrix verify that SMDJ45A is sourced from the original manufacturer or authorized distributors?
All SMDJ45A 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 SMDJ45A meets industry standards.
7.What is the process for return or replacement of SMDJ45A?
All SMDJ45A units undergo pre-shipment inspection (PSI). If there is an issue with SMDJ45A, 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 SMDJ45A part is unused and in its original packaging.
Return procedure for SMDJ45A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMDJ45A Tags
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