My Inquiry
My Account
Vishay General Semiconductor - Diodes Division SMAJ28A-M3/61
- Part No.:
- SMAJ28A-M3/61
- Manufacturer:
- Vishay General Semiconductor - Diodes Division
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ28A-M3/61.pdf
- Description:
- TVS DIODE 28VWM 45.4VC DO214AC
- Quantity:
- Payment:
- Shipping:
Inventory:8,517
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMAJ28A-M3/61 from Vishay General Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode designed for primary overvoltage protection of DC power rails and signal lines. It features a 28 V standoff voltage (VWM), 31.1–34.4 V breakdown voltage (VBR) at 1 mA, 45.4 V maximum clamping voltage (VC) at 8.8 A peak pulse current, and 400 W peak pulse power rating with 10/1000 μs waveform - deployed in automotive body control modules, industrial I/O interfaces, and USB power input stages.
For engineers reviewing the SMAJ28A-M3/61 datasheet, SMAJ28A-M3/61 pinout, SMAJ28A-M3/61 application, or SMAJ28A-M3/61 equivalent, key selection criteria include its unidirectional polarity, SMA (DO-214AC) package compatibility with automated SMT placement, AEC-Q101 qualification readiness (via HM3 suffix variants), and verified clamping performance under repetitive surge conditions per IEC 61000-4-5.
Technical Context
This TVS diode operates as a voltage-clamped shunt protector: when reverse voltage exceeds VBR, it avalanches to divert transient energy away from downstream ICs while maintaining VC ≤ 45.4 V at 8.8 A. Its glass-passivated junction ensures stable leakage (<1.0 μA at 28 V) and low incremental surge resistance for consistent clamping across temperature.
Designed for surface-mount assembly on standard PCB copper pads (0.2" × 0.2"), it delivers 400 W peak pulse power up to 78 V and derates to 300 W above that threshold. Thermal resistance is 120 °C/W (junction-to-ambient) and 30 °C/W (junction-to-lead), enabling reliable operation up to +150 °C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM (Stand-off Voltage) | 28 V - Maximum continuous reverse operating voltage before conduction begins; defines safe DC rail margin. |
| VBR (Breakdown Voltage) | 31.1–34.4 V at 1 mA - Confirmed avalanche onset range; ensures predictable turn-on during transients. |
| VC (Clamping Voltage) | 45.4 V at 8.8 A (10/1000 μs) - Maximum voltage seen by protected circuit during rated surge; critical for IC survivability. |
| PPPM (Peak Pulse Power) | 400 W - Sustained transient energy handling capability on standard pad layout; supports IEC 61000-4-5 Level 4 compliance. |
| IPPM (Peak Pulse Current) | 8.8 A - Peak surge current the device safely clamps without degradation; derived from VC and PPPM. |
| TJmax | +150 °C - Maximum junction temperature; enables use in under-hood automotive and high-ambient industrial environments. |
| Package | SMA (DO-214AC) - Standardized surface-mount outline with 5.28 mm length, 4.50 mm width, and 2.29 mm height; compatible with J-STD-020 MSL Level 1 reflow. |
Pinout & Package
Package: SMA (DO-214AC), molded plastic case with matte tin-plated leads; cathode indicated by band at one end; polarity-critical for unidirectional operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side connection point | Connected to ground or return path; completes shunt path during transient events. |
| Cathode | High-side connection point | Connected to protected line (e.g., 28 V rail); reverse-biased during normal operation; conducts during overvoltage. |
Key Features
| Feature | Design Value |
|---|---|
| 400 W peak pulse power (10/1000 μs) | Enables robust protection against lightning-induced surges and inductive switching spikes in 24 V systems. |
| Low clamping ratio (VC/VBR ≈ 1.34) | Minimizes stress on downstream components by tightly constraining transient voltage overshoot. |
| Glass-passivated junction | Ensures stable electrical characteristics and long-term reliability under thermal cycling and humidity exposure. |
| MSL Level 1, 260 °C peak reflow | Supports lead-free SMT assembly without preconditioning; eliminates moisture-related popcorning risk. |
| Halogen-free, RoHS-compliant (M3 suffix) | Fulfills environmental compliance requirements for automotive and industrial OEM supply chains. |
Applications
| Automotive Body Control Module (BCM) | Industrial PLC Digital Input |
|---|---|
|
Use Scenario: Protects 24 V supply inputs in BCMs from load-dump transients (ISO 7637-2 Pulse 5a) and alternator ripple. IC Role / Device Role / Timing Role: Shunt-type transient suppressor placed directly at power entry point before LDO regulators and microcontrollers. Use Value: Clamps 28 V rail to ≤45.4 V during 100 V/50 ms pulses, preventing brownout resets and gate oxide damage in MCU power domains. |
Use Scenario: Shields 24 V digital input channels in programmable logic controllers from field-wiring ESD and inductive kickback. IC Role / Device Role / Timing Role: Front-end protection element on optocoupler input side, absorbing fast-rising transients before signal conditioning. Use Value: Limits voltage excursion to <45.4 V within nanoseconds, preserving optocoupler CTR stability and eliminating false triggering. |
| USB-C Power Delivery (PD) Adapter Output | Telecom Remote Radio Unit (RRU) Bias Line |
|
Use Scenario: Safeguards 20–28 V output rails of USB PD adapters against hot-plug surges and cable ESD events. IC Role / Device Role / Timing Role: Secondary-stage clamp after primary DC-DC converter, complementing upstream ceramic capacitors. Use Value: Maintains output regulation integrity by clamping transients faster than feedback loop response time (<1 ns response). |
Use Scenario: Protects +28 V bias feed lines powering GaN amplifiers in outdoor RRUs exposed to lightning-induced ground potential rise. IC Role / Device Role / Timing Role: High-energy shunt protector mounted at antenna mast base, before inline DC blocking caps. Use Value: Absorbs >300 W surges without failure, ensuring amplifier uptime and avoiding costly tower service calls. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ28A-E3/61 | Same electrical specs; RoHS-compliant but not halogen-free; commercial-grade only (no AEC-Q101 path). | Preferred for cost-sensitive consumer electronics where halogen-free requirement is absent. | Select when environmental compliance mandates RoHS but not halogen-free; identical footprint and soldering profile. |
| SMAJ28AHM3_A/H | Identical electrical and thermal specs; includes AEC-Q101 qualification and halogen-free construction; packaged in 7" tape (H code). | Required for automotive front-end electronics requiring full PPAP documentation and lifetime reliability validation. | Choose for automotive OEM designs needing certified qualification; same PCB layout, no redesign needed. |
Compared with SMAJ28A-M3/61, the E3 variant offers lower cost without halogen-free assurance, while the HM3_A/H variant adds formal AEC-Q101 validation - making the M3/61 optimal for industrial applications needing halogen-free compliance without automotive certification overhead.
Availability
SMAJ28A-M3/61 is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O protection, and telecom power interface designs requiring stable component supply, halogen-free compliance, and repeatable surge performance.
Supply support for SMAJ28A-M3/61 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 targets board-level transient protection in harsh environments - engineered for fast response, low clamping, and robust thermal performance in automotive, industrial, and telecom infrastructure.
FAQ
What is the maximum clamping voltage of the SMAJ28A-M3/61 under a 10/1000 μs surge?
The SMAJ28A-M3/61 has a maximum clamping voltage (VC) of 45.4 V at 8.8 A peak pulse current with a 10/1000 μs waveform. This value is measured under standardized test conditions per JEDEC and IEC 61000-4-5, and represents the highest voltage the protected circuit will experience during a rated transient event. The SMAJ28A-M3/61 maintains this clamping performance across its full operating temperature range.
Is the SMAJ28A-M3/61 suitable for automotive applications?
The SMAJ28A-M3/61 itself is halogen-free and RoHS-compliant but not AEC-Q101 qualified. However, Vishay offers the functionally identical SMAJ28AHM3_A/H variant with full AEC-Q101 qualification. For non-safety-critical automotive subsystems (e.g., interior lighting, HVAC controls), the SMAJ28A-M3/61 may be used subject to customer qualification - but the SMAJ28A-M3/61 is explicitly intended for industrial and commercial applications per Vishay's ordering guidance.
What does the "M3" suffix indicate in SMAJ28A-M3/61?
The "M3" suffix in SMAJ28A-M3/61 denotes halogen-free, RoHS-compliant construction meeting JEDEC J-STD-201 Class 2 whisker resistance requirements. It differentiates the part from the "E3" (RoHS only) and "HM3" (AEC-Q101 + halogen-free) variants. The M3 material set ensures compliance with environmental regulations in industrial and consumer markets without adding automotive qualification overhead.
Can SMAJ28A-M3/61 be used in bidirectional configurations?
No - SMAJ28A-M3/61 is a unidirectional TVS diode, identifiable by its cathode band marking and specified VBR/VWM values for reverse bias only. Bidirectional operation requires the CA-suffixed variant (e.g., SMAJ28CA). Using SMAJ28A-M3/61 in bidirectional circuits risks forward conduction during negative transients, leading to failure. Always match polarity to system grounding architecture.
What is the thermal resistance of SMAJ28A-M3/61, and how does it affect PCB layout?
The SMAJ28A-M3/61 has a typical junction-to-ambient thermal resistance (RθJA) of 120 °C/W and junction-to-lead (RθJL) of 30 °C/W. To maintain TJ ≤ 150 °C under sustained 3.3 W dissipation, PCB copper pads must follow Vishay's recommended 0.2" × 0.2" (5.0 mm × 5.0 mm) layout per terminal. Reducing pad area increases thermal impedance and risks premature thermal runaway during repetitive surges.
SMAJ28A-M3/61 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:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 8.8A
- 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)
SMAJ28A-M3/61 FAQ
1.How can I place an order for SMAJ28A-M3/61 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ28A-M3/61 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 SMAJ28A-M3/61 reliable?
The price and inventory of SMAJ28A-M3/61 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ28A-M3/61 is usually 5 days.
3.What payment methods are accepted for SMAJ28A-M3/61?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ28A-M3/61 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ28A-M3/61?
SMAJ28A-M3/61 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ28A-M3/61 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 SMAJ28A-M3/61?
For technical support, including SMAJ28A-M3/61 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ28A-M3/61 requirements.
6.How does Aetrix verify that SMAJ28A-M3/61 is sourced from the original manufacturer or authorized distributors?
All SMAJ28A-M3/61 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 SMAJ28A-M3/61 meets industry standards.
7.What is the process for return or replacement of SMAJ28A-M3/61?
All SMAJ28A-M3/61 units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ28A-M3/61, 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 SMAJ28A-M3/61 part is unused and in its original packaging.
Return procedure for SMAJ28A-M3/61:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ28A-M3/61 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 …
