My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMAJ51CA-M3/5A
- Part No.:
- SMAJ51CA-M3/5A
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ51CA-M3/5A.pdf
- Description:
- TVS DIODE 51VWM 82.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:5,866
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ51CA-M3/5A from Vishay General Semiconductor is a bidirectional transient voltage suppressor (TVS) diode designed for robust overvoltage protection on signal and power lines. 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 safeguard MOSFETs, ICs, and sensor interfaces in automotive and industrial control systems.
For engineers reviewing the SMAJ51CA-M3/5A datasheet, SMAJ51CA-M3/5A pinout, SMAJ51CA-M3/5A application, or SMAJ51CA-M3/5A equivalent, key selection criteria include bidirectional clamping capability, low clamping ratio (VC/VWM = 1.62), halogen-free RoHS-compliant packaging (M3 suffix), AEC-Q101 qualification eligibility, and compatibility with automated SMT placement on DO-214AC footprints.
Technical Context
This device operates as a voltage-clamped shunt protector: under normal conditions it presents high impedance (>1 μA leakage at 51 V), but triggers into low-impedance conduction when transients exceed its breakdown threshold. Its glass-passivated junction ensures stable VBR tolerance (±5%) and fast response (<1 ns), enabling effective suppression of ESD, lightning-induced surges, and inductive switching spikes.
The SMAJ51CA-M3/5A is rated for 150 °C maximum junction temperature and exhibits a +0.104 %/°C temperature coefficient of VBR, supporting reliable operation across extended thermal ranges. Its 120 °C/W junction-to-ambient thermal resistance requires appropriate PCB copper pad area (0.2" × 0.2") to sustain repetitive 400 W pulses at ≤0.01% duty cycle.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before significant leakage; defines safe working margin below clamping onset. |
| VBR (min/max) | 56.7 V / 62.7 V at 1 mA - Confirmed breakdown range ensuring predictable turn-on behavior across production lots and temperature. |
| VC @ IPPM | 82.4 V at 4.9 A - Clamping voltage during 10/1000 μs surge; determines maximum stress imposed on protected downstream circuitry. |
| PPPM | 400 W - Peak pulse power handling per single transient; derates to 300 W above 78 V, confirmed for 0.01% duty cycle. |
| IFSM | 40 A - Non-repetitive forward surge rating (8.3 ms half-sine); validates robustness against accidental polarity reversals or fault currents. |
| TJ max | 150 °C - Maximum junction temperature; enables use in under-hood automotive and high-ambient industrial environments. |
| Package | SMA (DO-214AC) - Surface-mount package with 2.54 mm lead pitch; supports automated placement and meets UL 94 V-0 flammability. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads; polarity-unmarked for bidirectional operation; compliant with J-STD-002 and JESD 22-B102 solderability standards.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current return path (bidirectional) | Acts as cathode during positive transients and anode during negative transients; symmetrical conduction enables dual-polarity protection without polarity awareness. |
| Cathode | Transient current return path (bidirectional) | Electrically identical to Anode in CA devices; no marking distinguishes terminals; both leads function identically in either direction of surge. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating signal lines (e.g., CAN bus, RS-485, sensor bridges) without external polarity management. |
| 400 W peak pulse power | Validated for 10/1000 μs waveform on 5.0 mm × 5.0 mm copper pads; provides margin against IEC 61000-4-5 Level 3 (1 kV/2 Ω) surges. |
| Halogen-free & RoHS-compliant (M3) | Meets environmental compliance requirements for automotive and industrial OEMs; qualified per JESD 201 Class 2 whisker resistance. |
| AEC-Q101 qualification path | Base P/NHM3_X variant available with full automotive qualification; enables drop-in use in ADAS, body control, and powertrain modules. |
| Low clamping ratio (1.62) | VC/VWM = 82.4/51 = 1.62 - Minimizes voltage overshoot during clamping, reducing risk of latch-up or gate oxide damage in protected MOSFETs and ICs. |
Applications
| Automotive Power Line Protection | Industrial Sensor Interface Protection |
|---|---|
|
Use Scenario: Protecting 12 V battery-fed ECUs and lighting drivers from load dump and alternator ripple transients. IC Role / Device Role / Timing Role: Shunt TVS placed across input rails to clamp surges up to ±100 V before they reach DC-DC converters or microcontrollers. Use Value: Withstands 40 A IFSM and maintains <1 μA leakage at 51 V, ensuring minimal quiescent current drain and long-term reliability in always-on modules. |
Use Scenario: Safeguarding analog outputs and digital I/O of pressure/temperature sensors in factory automation PLCs. IC Role / Device Role / Timing Role: Bidirectional clamping element on 4–20 mA current loop or RS-485 differential pair to suppress ESD and cable discharge events. Use Value: Symmetrical VBR (56.7–62.7 V) and low VC (82.4 V) prevent false triggering while limiting downstream voltage excursion to safe levels for 3.3 V/5 V logic. |
| Consumer USB Port ESD Protection | Telecom DSL Line Surge Suppression |
|
Use Scenario: Secondary-level protection on USB VBUS and D+/D− lines in set-top boxes and smart displays. IC Role / Device Role / Timing Role: Fast-response shunt device absorbing IEC 61000-4-2 ±15 kV contact discharge energy before it reaches USB transceivers. Use Value: Sub-nanosecond response time and 82.4 V clamping ensure transceiver I/O remains within absolute maximum ratings even during worst-case ESD events. |
Use Scenario: Primary surge protection on twisted-pair DSL line cards exposed to induced lightning surges in outdoor cabinets. IC Role / Device Role / Timing Role: Bidirectional TVS installed across tip/ring to divert common-mode surges exceeding 51 V standoff level. Use Value: 400 W pulse rating and 150 °C TJ max enable sustained operation in unventilated telecom enclosures with ambient temperatures up to 85 °C. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51CA-E3/5A | Same electrical specs and DO-214AC package; RoHS-compliant but contains brominated flame retardants (non-halogen-free). | Approved for commercial-grade industrial and consumer use; not accepted in halogen-free automotive supply chains. | Select when halogen-free requirement is not mandated and cost sensitivity favors standard E3 variant. |
| SMBJ51CA-M3 | Higher 600 W PPPM rating, same VWM/VC; larger SMB (DO-214AA) package with 4.3 mm width vs. SMA's 2.8 mm. | Used where higher surge margin is required (e.g., outdoor telecom, EV charging stations); requires PCB layout change. | Choose when system-level surge testing exceeds 400 W and board space allows wider footprint. |
Compared with SMAJ51CA-E3/5A, the M3 version adds halogen-free compliance critical for Tier 1 automotive sourcing; compared with SMBJ51CA-M3, the SMAJ51CA-M3/5A offers identical protection performance in a 30% smaller footprint-ideal for space-constrained sensor nodes and portable electronics.
Availability
SMAJ51CA-M3/5A is available at Aetrix Electronics and suitable for automotive ECU design, industrial sensor interface development, and telecom line card prototyping requiring stable component supply and halogen-free compliance.
Supply support for SMAJ51CA-M3/5A 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, precision, and application-specific optimization.
The SMAJ series targets surface-mount transient suppression in space-constrained, high-reliability applications-including automotive, industrial controls, and communications-where consistent clamping, low leakage, and AEC-Q101 readiness are essential.
FAQ
What is the clamping voltage of the SMAJ51CA-M3/5A under a 10/1000 μs surge?
The SMAJ51CA-M3/5A has a maximum clamping voltage (VC) of 82.4 V at 4.9 A peak pulse current (IPPM) for a 10/1000 μs waveform. This value is measured per Figure 1 in Vishay document 88390 and defines the upper voltage limit imposed on protected circuitry during standardized surge events. The SMAJ51CA-M3/5A maintains this clamping performance across its specified operating temperature range.
Is the SMAJ51CA-M3/5A suitable for automotive applications?
Yes-the SMAJ51CA-M3/5A is manufactured with halogen-free, RoHS-compliant materials (M3 suffix) and supports AEC-Q101 qualification via the HM3_X variant (e.g., SMAJ51CAHM3_A/I). While the base SMAJ51CA-M3/5A is commercial-grade, its electrical specs, 150 °C TJ max, and robust surge rating make it suitable for non-safety-critical automotive subsystems such as infotainment power rails and body electronics. The SMAJ51CA-M3/5A must be paired with appropriate thermal layout for sustained operation.
How does the bidirectional design of the SMAJ51CA-M3/5A affect its circuit implementation?
The SMAJ51CA-M3/5A has no polarity marking and conducts symmetrically in both directions, making it ideal for protecting AC-coupled or floating nodes-such as RS-485 differential pairs, CAN bus lines, or bridge sensor outputs-without requiring orientation-aware placement. Unlike unidirectional TVS diodes, the SMAJ51CA-M3/5A eliminates risk of incorrect installation and simplifies layout by removing the need for series blocking diodes. Its bidirectional behavior is intrinsic to the device structure, not achieved via back-to-back configuration.
What is the thermal resistance of the SMAJ51CA-M3/5A, and how does it impact PCB layout?
The SMAJ51CA-M3/5A has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W when mounted on minimum recommended 0.2" × 0.2" (5.0 mm × 5.0 mm) copper pads per terminal. To sustain repetitive 400 W pulses, the PCB must provide adequate copper area and thermal vias; insufficient copper increases junction temperature and risks derating or failure. The SMAJ51CA-M3/5A's RθJL of 30 °C/W further emphasizes the importance of low-impedance thermal paths to internal ground planes.
Does the SMAJ51CA-M3/5A have a specified junction capacitance, and is it suitable for high-speed data lines?
The SMAJ51CA-M3/5A does not specify junction capacitance (CJ) in its primary datasheet (88390), and Vishay's typical CJ curves for the SMAJ family show values >200 pF at low bias-too high for USB 2.0, HDMI, or Gigabit Ethernet signal integrity. It is intended for power rail and low-to-medium speed signal protection (e.g., RS-232, RS-485, analog sensor outputs), not high-frequency data lanes. For such applications, dedicated low-capacitance TVS arrays or ESD suppressors should be used instead of the SMAJ51CA-M3/5A.
SMAJ51CA-M3/5A 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:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-214AC (SMA)
SMAJ51CA-M3/5A FAQ
1.How can I place an order for SMAJ51CA-M3/5A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ51CA-M3/5A 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 SMAJ51CA-M3/5A reliable?
The price and inventory of SMAJ51CA-M3/5A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ51CA-M3/5A is usually 5 days.
3.What payment methods are accepted for SMAJ51CA-M3/5A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ51CA-M3/5A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ51CA-M3/5A?
SMAJ51CA-M3/5A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ51CA-M3/5A 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 SMAJ51CA-M3/5A?
For technical support, including SMAJ51CA-M3/5A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ51CA-M3/5A requirements.
6.How does Aetrix verify that SMAJ51CA-M3/5A is sourced from the original manufacturer or authorized distributors?
All SMAJ51CA-M3/5A 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 SMAJ51CA-M3/5A meets industry standards.
7.What is the process for return or replacement of SMAJ51CA-M3/5A?
All SMAJ51CA-M3/5A units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ51CA-M3/5A, 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 SMAJ51CA-M3/5A part is unused and in its original packaging.
Return procedure for SMAJ51CA-M3/5A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ51CA-M3/5A Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
