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Vishay General Semiconductor - Diodes Division SMAJ51CAHM3_A/I
- Part No.:
- SMAJ51CAHM3_A/I
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51CAHM3_A/I.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:9,557
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Product details
Overview
SMAJ51CAHM3_A/I from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in SMA (DO-214AC) package, designed for robust overvoltage protection of sensitive electronics. It features a 51 V standoff voltage (VWM), 56.7–62.7 V breakdown range (VBR at 1 mA), 82.4 V maximum clamping voltage (VC) at 4.9 A peak pulse current, and 400 W peak pulse power (10/1000 μs waveform). It is widely deployed to protect MOSFETs, ICs, and sensor signal lines in automotive and industrial power systems.
For engineers reviewing the SMAJ51CAHM3_A/I datasheet, SMAJ51CAHM3_A/I pinout, SMAJ51CAHM3_A/I application, or SMAJ51CAHM3_A/I equivalent, this device serves as a halogen-free, AEC-Q101-qualified TVS for bidirectional surge suppression in 12 V/24 V automotive subsystems, industrial I/O interfaces, and DC power rail protection where low clamping voltage and fast response (<1 ns) are critical.
Technical Context
This bidirectional TVS operates symmetrically across both polarities, with identical electrical characteristics in forward and reverse directions. Its glass-passivated junction enables stable breakdown behavior and low incremental surge resistance, while the SMA package supports automated SMT placement and meets MSL Level 1 (260 °C reflow peak).
The device delivers 400 W peak pulse power up to 78 V and derates to 300 W above that threshold, with thermal resistance of 120 °C/W (junction-to-ambient) and 30 °C/W (junction-to-lead). It sustains 40 A non-repetitive forward surge current (8.3 ms half-sine) and operates from –55 °C to +150 °C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; defines safe DC/AC working margin for 12 V/24 V systems. |
| VBR (min/max) | 56.7 V / 62.7 V at 1 mA - Verified breakdown onset range ensures reliable triggering without premature conduction under normal operation. |
| VC @ IPPM | 82.4 V at 4.9 A - Clamping voltage during 10/1000 μs surge; limits downstream voltage stress to <83 V under worst-case transients. |
| PPPM | 400 W - Peak pulse power handling capability per 10/1000 μs waveform; sufficient for ISO 7637-2 Pulse 1/2a/5a and IEC 61000-4-5 Level 3 surges. |
| IFSM | 40 A - Single half-sine surge rating (8.3 ms); supports high-energy inductive switch-off events in automotive solenoid drivers. |
| TJ max | +150 °C - Maximum junction temperature; enables use in under-hood automotive modules and industrial enclosures without active cooling. |
| Package | SMA (DO-214AC) - Surface-mount outline with 5.28 mm × 4.50 mm footprint; compatible with standard 0.2" × 0.2" copper pads for optimal thermal dissipation. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads, RoHS-compliant and halogen-free (HM3 suffix), MSL Level 1 rated.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal in forward bias | For bidirectional operation, no polarity marking; terminals are symmetrical and interchangeable in circuit layout. |
| Cathode | Current exit terminal in forward bias | Identical to Anode in bidirectional configuration; both terminals function identically under positive or negative transients. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD testing - suitable for engine control, body electronics, and ADAS power domains. |
| 400 W peak pulse power | Withstands repetitive 10/1000 μs surges up to 0.01% duty cycle - protects against load dump and inductive kickback in 12 V/24 V systems. |
| Low clamping ratio (VC/VWM ≈ 1.62) | Minimizes overvoltage overshoot during clamping - preserves margin for 5 V/3.3 V logic interfaces downstream of protected nodes. |
| Glass-passivated junction | Ensures stable VBR tolerance and long-term leakage stability - critical for low-power sensor front-ends and always-on circuits. |
| Halogen-free & RoHS-compliant | Meets JESD201 Class 2 whisker resistance and UL 94 V-0 flammability - supports green manufacturing and global compliance requirements. |
Applications
| Automotive Power Distribution | Industrial Sensor Signal Lines |
|---|---|
Use Scenario: Protection of 12 V battery-fed ECUs against load dump (ISO 7637-2 Pulse 5a) and alternator ripple. IC Role / Device Role / Timing Role: Bidirectional shunt clamp placed across input rails upstream of DC/DC converters and LDOs. Use Value: Limits transient voltage to ≤82.4 V, preventing damage to 60 V-rated input stages and enabling single-stage protection architecture. |
Use Scenario: Shielding analog outputs (e.g., 4–20 mA, 0–10 V) of pressure/temperature sensors from ESD and field-induced surges. IC Role / Device Role / Timing Role: Low-capacitance (≈100 pF at 0 V) parallel clamp on differential or single-ended signal traces. Use Value: Maintains signal integrity with sub-nanosecond response and <1 μA leakage at 51 V, avoiding offset drift in precision measurement paths. |
| DC Motor Drive Outputs | Telecom Power Interface |
Use Scenario: Suppressing inductive flyback spikes from brushed DC motors in HVAC actuators and seat controls. IC Role / Device Role / Timing Role: Fast-acting clamp across H-bridge output terminals or motor terminals. Use Value: Absorbs 40 A surge energy (8.3 ms) without degradation, eliminating need for snubber RC networks and reducing BOM count. |
Use Scenario: Protecting PoE-powered equipment (e.g., IP cameras, access points) from lightning-induced surges on 48 V DC input lines. IC Role / Device Role / Timing Role: Primary-level bidirectional TVS on DC input before DC/DC isolation stage. Use Value: Withstands 300 W surge above 78 V (per IEC 61000-4-5), enabling compliance with EN 61000-4-5 Level 3 without cascaded protection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51CAHE3_A/I | Same electrical specs and AEC-Q101 qualification, but RoHS-compliant with brominated flame retardant (non-halogen-free). | Acceptable for commercial/industrial designs where halogen-free requirement is not mandated. | Select when cost sensitivity outweighs halogen-free compliance; identical footprint and assembly process. |
| SMBJ51CAHM3_A/I | Higher 600 W peak pulse power (10/1000 μs), same VWM/VC, but larger SMB (DO-214AA) package (5.3 mm × 4.1 mm vs. SMA's 4.5 mm × 3.99 mm). | Better suited for higher-energy surges (e.g., ISO 16750-2 Load Dump) but requires PCB layout revision. | Choose when system-level surge testing exceeds 400 W margin; verify board space and thermal pad compatibility. |
Compared with SMAJ51CAHM3_A/I, the HE3 variant trades halogen-free status for lower unit cost without performance loss, while the SMBJ51CAHM3_A/I offers +50 % pulse power headroom at the expense of footprint size - making SMAJ51CAHM3_A/I optimal for space-constrained AEC-Q101 applications needing precise 400 W capability.
Availability
SMAJ51CAHM3_A/I is available at Aetrix Electronics and suitable for automotive electronic control units, industrial sensor interfaces, and telecom power input stages requiring stable component supply with full traceability and lifecycle continuity.
Supply support for SMAJ51CAHM3_A/I 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 diodes, rectifiers, MOSFETs, and protection devices with emphasis on reliability, efficiency, and application-specific optimization.
The SMAJ series is engineered for high-reliability transient suppression in harsh environments - targeting automotive, industrial, and telecom systems where robustness, AEC-Q101 validation, and consistent clamping performance are mandatory.
FAQ
What is the clamping voltage of SMAJ51CAHM3_A/I at its rated peak pulse current?
The SMAJ51CAHM3_A/I has a maximum clamping voltage (VC) of 82.4 V at 4.9 A peak pulse current (IPPM) under a 10/1000 μs waveform. This value is measured per JEDEC standards and guarantees that downstream components see no more than 82.4 V during specified surge events - a critical parameter for ensuring compatibility with 60 V-rated power management ICs and gate drivers in the same design.
Is SMAJ51CAHM3_A/I suitable for automotive applications?
Yes, SMAJ51CAHM3_A/I is AEC-Q101 qualified and manufactured with halogen-free, RoHS-compliant materials (HM3 suffix). It meets automotive requirements for temperature cycling, high-temperature reverse bias, and surge robustness - making it appropriate for under-hood modules, body control units, and ADAS power supplies where reliability under thermal and electrical stress is essential.
How does the bidirectional configuration of SMAJ51CAHM3_A/I affect circuit implementation?
The SMAJ51CAHM3_A/I has no polarity marking and functions identically in both directions - simplifying layout by eliminating cathode/anode orientation checks. This symmetry allows direct placement across unidirectional DC rails (e.g., 12 V and GND) or AC-coupled signal lines without concern for voltage polarity reversal, reducing design risk and assembly errors in high-volume automotive and industrial production.
What is the thermal resistance of SMAJ51CAHM3_A/I, and how does it impact PCB layout?
SMAJ51CAHM3_A/I has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W and junction-to-lead (RθJL) of 30 °C/W. To maintain safe operation at full 400 W pulse power, the datasheet specifies mounting on 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal - underscoring the need for adequate copper area and optional thermal vias to avoid exceeding the +150 °C maximum junction temperature during repetitive surge events.
Does SMAJ51CAHM3_A/I meet any safety or flammability certifications?
Yes, SMAJ51CAHM3_A/I's molding compound meets UL 94 V-0 flammability rating, and the device carries Underwriters Laboratories Recognition (QVGQ2) under UL 497B for protector classification (file E136766). These certifications validate its suitability for end-equipment requiring fire-safety compliance, including automotive infotainment systems, industrial PLCs, and telecom infrastructure hardware.
SMAJ51CAHM3_A/I Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Package/Case:
- DO-214AC, SMA
- Series:
- TransZorb®
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 4.9A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ51CAHM3_A/I FAQ
1.How can I place an order for SMAJ51CAHM3_A/I through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51CAHM3_A/I 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 SMAJ51CAHM3_A/I reliable?
The price and inventory of SMAJ51CAHM3_A/I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ51CAHM3_A/I is usually 5 days.
3.What payment methods are accepted for SMAJ51CAHM3_A/I?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51CAHM3_A/I transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51CAHM3_A/I?
SMAJ51CAHM3_A/I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51CAHM3_A/I 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 SMAJ51CAHM3_A/I?
For technical support, including SMAJ51CAHM3_A/I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51CAHM3_A/I requirements.
6.How does Aetrix verify that SMAJ51CAHM3_A/I is sourced from the original manufacturer or authorized distributors?
All SMAJ51CAHM3_A/I 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 SMAJ51CAHM3_A/I meets industry standards.
7.What is the process for return or replacement of SMAJ51CAHM3_A/I?
All SMAJ51CAHM3_A/I units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51CAHM3_A/I, 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 SMAJ51CAHM3_A/I part is unused and in its original packaging.
Return procedure for SMAJ51CAHM3_A/I:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ51CAHM3_A/I Tags
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