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Vishay General Semiconductor - Diodes Division 3KASMC28HE3/9AT
- Part No.:
- 3KASMC28HE3/9AT
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
3KASMC28HE3/9AT.pdf
- Description:
- TVS DIODE 28VWM 50VC DO214AB
- Quantity:
- Payment:
- Shipping:
Inventory:4,128
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Product details
Overview
3KASMC28HE3/9AT from Vishay General Semiconductor is a unidirectional surface-mount PAR® transient voltage suppressor (TVS) designed for high-energy surge clamping in automotive and industrial power rails. It delivers 3000 W peak pulse power (10/1000 μs), clamps at 45.4 V under 66.1 A surge current, and operates up to 185 °C junction temperature - enabling robust protection of MOSFETs and ICs against inductive switching transients in engine control units and power converters.
For engineers reviewing the 3KASMC28HE3/9AT datasheet, 3KASMC28HE3/9AT pinout, 3KASMC28HE3/9AT application, or 3KASMC28HE3/9AT equivalent, this page provides verified electrical parameters, DO-214AB package details, AEC-Q101 qualification status, thermal resistance data, and real-world use cases in automotive sensor power conditioning and DC bus overvoltage suppression.
Technical Context
This TVS diode employs passivated anisotropic rectifier technology optimized for high-temperature stability and low incremental surge resistance. Its unidirectional structure enables forward-biased conduction during positive transients while maintaining 28 V stand-off voltage and 31.1–34.4 V breakdown range at 1 mA test current.
It meets J-STD-020 MSL Level 1 with 260 °C reflow peak, supports 200 A non-repetitive forward surge (8.3 ms half-sine), and exhibits 77.5 °C/W junction-to-ambient thermal resistance on standard PCB pad layout - critical for thermal design in space-constrained automotive modules.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 28 V - Maximum reverse working voltage before clamping begins; defines safe operating margin for 24 V nominal systems. |
| VBR min/max | 31.1 V / 34.4 V at 1 mA - Confirmed breakdown threshold ensures reliable triggering above system operating voltage. |
| PPPM | 3000 W (10/1000 μs) - Sustains high-energy surges common in automotive load-dump and inductive kick events. |
| VC @ IPPM | 45.4 V at 66.1 A - Clamping voltage limits downstream device stress during worst-case transient conditions. |
| TJ max | 185 °C - Enables operation in under-hood environments without derating in high-ambient applications. |
| RθJA | 77.5 °C/W - Thermal resistance measured on minimum recommended pad layout; informs heatsinking requirements. |
| AEC-Q101 | Qualified - Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing. |
Pinout & Package
Package: DO-214AB (SMC), surface-mount, matte tin-plated leads, RoHS-compliant, UL 94 V-0 molding compound. Cathode denoted by color band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction | Connected to protected circuit ground or low-side return path; enables clamping when cathode voltage exceeds VWM. |
| Cathode | Current exit terminal during forward conduction | Connected to protected line (e.g., 24 V rail); reverse-biased under normal operation, avalanches during overvoltage. |
Key Features
| Feature | Design Value |
|---|---|
| Junction passivation | Optimized anisotropic rectifier process ensures stable leakage and breakdown behavior across 150 °C operating range. |
| Clamping performance | Low VC/VBR ratio (1.31) confirms efficient energy diversion with minimal overshoot during fast transients. |
| Surge robustness | 200 A IFSM (8.3 ms) supports repeated exposure to alternator load-dump pulses without degradation. |
| Manufacturing compliance | Meets JESD201 Class 2 whisker resistance and J-STD-002 solderability standards for high-yield SMT assembly. |
Applications
| Automotive Engine Control Unit (ECU) Power Rail Protection | Industrial PLC Digital Input Protection |
|---|---|
Use Scenario: Suppresses load-dump transients (up to 60 V, 100 ms) induced by alternator disconnection in 24 V vehicle systems. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and LDO input to clamp overvoltage before it reaches sensitive regulators and microcontrollers. Use Value: Prevents latch-up or permanent damage to 3.3 V/5 V logic supplies by limiting rail voltage to ≤45.4 V during 3000 W surge events. |
Use Scenario: Protects 24 V digital input channels from field-wiring induced surges in factory automation cabinets. IC Role / Device Role / Timing Role: Front-end transient suppressor on optocoupler input side, absorbing inductive kickback from solenoid or relay coils. Use Value: Maintains signal integrity by holding input voltage below 45.4 V during 66.1 A transients, ensuring reliable state detection without false triggering. |
| DC-DC Converter Output Stage Protection | Telecom Power Supply Surge Suppression |
Use Scenario: Guards isolated 12 V output of automotive buck converter against cross-talk and coupling from adjacent high-current paths. IC Role / Device Role / Timing Role: Secondary-side TVS connected from output rail to ground, activated only during fault conditions exceeding 28 V. Use Value: Limits output overvoltage to safe levels (<45.4 V) during MOSFET shoot-through or controller failure, preserving downstream FPGAs and ADCs. |
Use Scenario: Shields 48 V telecom power distribution boards from lightning-induced surges entering via long cable runs. IC Role / Device Role / Timing Role: Primary clamping device on main DC feed, coordinated with upstream GDTs to handle multi-kW transient energy. Use Value: Absorbs 3000 W peak power within 1000 μs window, reducing let-through voltage to <45.4 V and preventing burnout of point-of-load converters. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ28A | Lower PPPM (400 W), same DO-214AC (SMA) package, VC = 45.7 V at 8.3 A | Not rated for 185 °C operation; limited to commercial/industrial ambient (TJ max = 150 °C) | Acceptable for non-automotive 24 V systems where surge energy is ≤400 W and ambient <125 °C. |
| SMCJ28A | Same DO-214AB (SMC) package, identical VWM/VBR, but lower TJ max (175 °C) and no AEC-Q101 qualification | Lacks automotive qualification; thermal resistance slightly higher (RθJA = 80 °C/W) | Valid alternative for industrial motor drives where AEC-Q101 is not mandated and 10 °C junction margin is acceptable. |
Compared with SMAJ28A and SMCJ28A, the 3KASMC28HE3/9AT offers superior high-temperature capability (185 °C), full AEC-Q101 validation, and 7.5× higher peak pulse power - making it the only option qualified for under-hood automotive deployment requiring sustained reliability at extreme thermal stress.
Availability
3KASMC28HE3/9AT is available at Aetrix Electronics and suitable for automotive ECU designs, industrial PLC input stages, DC-DC converter outputs, and telecom power supply surge protection requiring stable component supply and long-term lifecycle support.
Supply support for 3KASMC28HE3/9AT 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
Vishay General Semiconductor is a global leader in discrete semiconductors, specializing in high-reliability diodes, MOSFETs, and passive components for automotive, industrial, and computing markets.
The 3KASMC series belongs to Vishay's PAR® TVS platform engineered specifically for AEC-Q101-compliant, high-temperature-stable transient suppression in harsh-environment power electronics.
FAQ
What is the maximum clamping voltage of the 3KASMC28HE3/9AT under peak surge conditions?
The 3KASMC28HE3/9AT clamps at 45.4 V when subjected to its rated peak pulse current of 66.1 A (10/1000 μs waveform). This value is measured per ANSI/IEEE C62.35 and confirmed in the Vishay datasheet revision 05-Mar-13, Document Number 89962. The clamping voltage directly determines the maximum stress imposed on downstream components during transient events, making it a critical parameter for system-level overvoltage design margins in the 3KASMC28HE3/9AT application.
Is the 3KASMC28HE3/9AT qualified for automotive use?
Yes, the 3KASMC28HE3/9AT is AEC-Q101 qualified, as explicitly stated in the Vishay datasheet (Document Number 89962, page 1). It has undergone stress testing including high-temperature reverse bias (HTRB), temperature cycling, and ESD per AEC-Q101 requirements. This qualification validates its suitability for automotive powertrain and body electronics applications where the 3KASMC28HE3/9AT serves as primary transient protection on 24 V battery rails and sensor interfaces.
What package type does the 3KASMC28HE3/9AT use, and what are its key mechanical features?
The 3KASMC28HE3/9AT uses the DO-214AB (SMC) surface-mount package, with dimensions of 6.22 mm × 5.59 mm × 2.41 mm (L × W × H). Key mechanical features include UL 94 V-0 compliant molding compound, matte tin-plated leads meeting J-STD-002 solderability, and cathode identification via a visible color band. These attributes ensure compatibility with automated SMT assembly and long-term reliability in vibration-prone automotive environments where the 3KASMC28HE3/9AT is deployed.
How does the 3KASMC28HE3/9AT differ from standard SMAJ or SMCJ series TVS diodes?
The 3KASMC28HE3/9AT differs from SMAJ/SMCJ series by offering 185 °C maximum junction temperature (vs. 150 °C for SMAJ, 175 °C for SMCJ), full AEC-Q101 qualification, and optimized passivated anisotropic rectifier technology for improved high-temperature leakage stability. While SMAJ28A and SMCJ28A share similar VWM and VC, only the 3KASMC28HE3/9AT meets automotive under-hood thermal and reliability requirements - a distinction critical for selecting the correct variant in safety-critical 3KASMC28HE3/9AT deployments.
What is the thermal resistance specification for the 3KASMC28HE3/9AT, and how is it measured?
The 3KASMC28HE3/9AT has a typical junction-to-ambient thermal resistance (RθJA) of 77.5 °C/W, measured on the minimum recommended PCB pad layout per JEDEC standards. This value assumes natural convection cooling on a standard FR-4 board with copper area defined in the Vishay datasheet (page 4). Accurate thermal modeling using this RθJA is essential to prevent junction overheating during repetitive surge events in the 3KASMC28HE3/9AT application, especially in enclosed automotive enclosures.
3KASMC28HE3/9AT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AB, SMC
- Series:
- PAR®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 50V
- Current - Peak Pulse (10/1000µs):
- 60A
- Power - Peak Pulse:
- 3000W (3kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 185°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AB (SMCJ)
3KASMC28HE3/9AT FAQ
1.How can I place an order for 3KASMC28HE3/9AT through Aetrix?
Please submit a Request for Quotation (RFQ) for 3KASMC28HE3/9AT 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 3KASMC28HE3/9AT reliable?
The price and inventory of 3KASMC28HE3/9AT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 3KASMC28HE3/9AT is usually 5 days.
3.What payment methods are accepted for 3KASMC28HE3/9AT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 3KASMC28HE3/9AT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 3KASMC28HE3/9AT?
3KASMC28HE3/9AT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 3KASMC28HE3/9AT 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 3KASMC28HE3/9AT?
For technical support, including 3KASMC28HE3/9AT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 3KASMC28HE3/9AT requirements.
6.How does Aetrix verify that 3KASMC28HE3/9AT is sourced from the original manufacturer or authorized distributors?
All 3KASMC28HE3/9AT 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 3KASMC28HE3/9AT meets industry standards.
7.What is the process for return or replacement of 3KASMC28HE3/9AT?
All 3KASMC28HE3/9AT units undergo pre-shipment inspection (PSI). If there is an issue with 3KASMC28HE3/9AT, 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 3KASMC28HE3/9AT part is unused and in its original packaging.
Return procedure for 3KASMC28HE3/9AT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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