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onsemi 1SMA26AT3
- Part No.:
- 1SMA26AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA26AT3.pdf
- Description:
- TVS DIODE 26VWM 42.1VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:8,553
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Product details
Overview
1SMA26AT3 from ON Semiconductor is a unidirectional 400 W peak power Zener transient voltage suppressor (TVS) designed for clamping high-energy transients in DC power rails and signal lines. It features a 26 V working peak reverse voltage (VRWM), 30.4 V nominal breakdown voltage (VBR) at 1 A test current, 42.1 A maximum peak pulse current (IPP), and clamps to 42.1 V at that current. It is used in automotive power supply protection and industrial control I/O interfaces.
For engineers reviewing the 1SMA26AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, VC ≤ protected IC's absolute maximum rating, fast <1 ns response, and SMA package compatibility with automated SMT assembly on FR-4 PCBs.
Technical Context
The 1SMA26AT3 operates as a unidirectional avalanche diode, conducting only during negative transients relative to its anode–cathode orientation. Its clamping action begins at VBR ≈ 30.4 V and limits voltage to VC = 42.1 V under 42.1 A 10/1000 µs surge, delivering robust protection without crowbar behavior.
It exhibits low zener impedance, ESD rating >16 kV HBM, and thermal resistance RJA = 250 °C/W on standard FR-4 layout. The device is rated for −65 °C to +150 °C operation and supports top-slide or bottom-mount placement in the SMA (Case 403D-02) surface-mount package.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Peak Reverse Voltage (VRWM) | 26 V - Maximum continuous DC or peak AC voltage the device blocks without clamping; must exceed circuit operating voltage. |
| Breakdown Voltage (VBR) @ IT = 1 A | 30.4 V (nominal) - Avalanche conduction initiates here; defines minimum clamping threshold under standardized test conditions. |
| Clamping Voltage (VC) @ IPP = 42.1 A | 42.1 V - Maximum voltage seen by downstream circuit during full-rated 10/1000 µs surge; determines protection margin. |
| Peak Pulse Power (PPK) | 400 W @ 1 ms - Surge energy handling capacity per single non-repetitive event; validated per REA 10/1000 µs waveform. |
| Response Time | <1 ns - Time from transient onset to clamping onset; ensures protection of fast-edge digital and analog circuits. |
| ESD Rating (HBM) | >16 kV - Withstands human-body-model electrostatic discharge events without degradation; qualifies for rugged interface design. |
Pinout & Package
The 1SMA26AT3 is housed in the SMA (DO-214AC, Case 403D-02) surface-mount plastic package, measuring 4.57 mm × 2.92 mm × 2.41 mm (L × W × H), with flat handling surface and cathode indicated by molded band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction or transient clamping (reverse-biased mode) | Connected to lower-potential side (e.g., GND or return path); defines polarity-sensitive placement on PCB. |
| Cathode | Current exit terminal during clamping; marked by band/notch | Connected to protected line (e.g., 24 V rail); voltage clamping occurs between cathode and anode when transient exceeds VRWM. |
Key Features
| Feature | Design Value |
|---|---|
| 400 W peak pulse power rating | Enables protection against IEC 61000-4-5 Level 4 surges (e.g., 4 kV line-to-ground) on 24 V systems without derating. |
| Low-profile SMA package (Case 403D-02) | Supports high-density PCB layouts and automated pick-and-place; compatible with standard reflow profiles (260°C/10 s max). |
| Fast <1 ns response time | Prevents overshoot damage to sensitive microcontrollers, CAN transceivers, and sensor front-ends before clamping engages. |
| Pb-free (1SMA26AT3G) and RoHS-compliant option | Meets global environmental compliance requirements without performance trade-offs; identical electrical specs to leaded version. |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module (BCM) Power Rails |
|---|---|
Use Scenario: 24 V DC input terminals on programmable logic controller modules exposed to load dump and inductive switching noise. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 24 V rail and chassis ground to clamp transients above 26 V. Use Value: Limits voltage to ≤42.1 V during 400 W surges, protecting downstream DC-DC converters and isolation amplifiers rated to 45 V abs max. |
Use Scenario: 12 V/24 V power distribution networks in BCMs subject to ISO 7637-2 pulse 1, 2a, and 5a. IC Role / Device Role / Timing Role: Primary overvoltage clamp on fused battery feed lines upstream of LDOs and MCU power supplies. Use Value: Survives 10/1000 µs surges up to 42.1 A while maintaining <1 ns response-critical for preserving reset integrity and EEPROM data retention. |
| Medical Equipment Power Entry | Telecom Remote Radio Unit (RRU) DC Feeds |
Use Scenario: AC/DC adapter output stage feeding isolated DC-DC converters in Class II medical devices. IC Role / Device Role / Timing Role: Secondary transient suppressor after primary MOV, guarding against fast-rising line disturbances. Use Value: Provides precise 26 V standoff and 42.1 V clamping-tighter tolerance than MOVs-to avoid nuisance tripping of safety-critical monitoring circuits. |
Use Scenario: −48 V DC power input on outdoor RRUs mounted on cell towers, exposed to lightning-induced surges. IC Role / Device Role / Timing Role: First-stage unidirectional clamp on telecom power bus, coordinated with upstream gas discharge tube (GDT). Use Value: Fast <1 ns turn-on ensures GDT has time to arc over, enabling staged protection with low let-through energy (<10 mJ) to downstream DC-DC controllers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ26A (ON Semiconductor) | Same VRWM (26 V) and VC (42.1 V), but higher PPK = 600 W in larger SMB package; RJA = 150 °C/W vs. 250 °C/W. | Better surge endurance in space-constrained 24 V systems where board area allows SMB footprint. | Select SMBJ26A when higher single-pulse energy (600 W) is required and PCB layout accommodates larger 4.6 × 3.9 mm package. |
| 1.5SMC26A (ON Semiconductor) | Same electrical specs (VRWM = 26 V, VC = 42.1 V), but in larger SMC (DO-214AB) package; PPK = 1500 W, RJA = 100 °C/W. | Used in high-reliability power supply inputs where thermal mass and surge margin outweigh size constraints. | Choose 1.5SMC26A for mains-connected equipment requiring >1 kW surge rating and superior thermal dissipation on heavy copper planes. |
Compared with SMBJ26A and 1.5SMC26A, the 1SMA26AT3 delivers identical clamping performance in the smallest footprint (SMA), making it optimal for compact industrial sensors and automotive ECUs where board space is premium and 400 W surge immunity suffices.
Availability
1SMA26AT3 is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive BCM power rails, and medical equipment power entry requiring stable component supply and long-term lifecycle support.
Supply support for 1SMA26AT3 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
ON Semiconductor (now part of onsemi) is a global semiconductor supplier specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and medical markets.
The 1SMA26AT3 belongs to the SMA-series unidirectional TVS family, engineered for cost-effective, high-reliability transient suppression in space-constrained SMT applications across automotive and industrial control systems.
FAQ
What is the clamping voltage of the 1SMA26AT3 under full-rated surge current?
The 1SMA26AT3 clamps to 42.1 V when subjected to its maximum rated peak pulse current of 42.1 A (10/1000 µs waveform). This value is measured per standard test conditions and defines the upper voltage limit imposed on protected circuitry during worst-case transient events. The 1SMA26AT3 maintains this clamping performance across its specified operating temperature range.
Is the 1SMA26AT3 suitable for bidirectional transient protection?
No, the 1SMA26AT3 is a unidirectional TVS diode and conducts only during reverse-biased transients. For bidirectional protection, ON Semiconductor offers the 1SMA26CAT3 variant. Using the 1SMA26AT3 in bidirectional applications risks failure during positive-going transients, as it lacks symmetrical clamping capability.
What is the thermal resistance of the 1SMA26AT3 on a standard FR-4 PCB?
The 1SMA26AT3 has a junction-to-ambient thermal resistance (RJA) of 250 °C/W when mounted on an FR-4 board using ON Semiconductor's recommended minimum footprint. This value assumes no thermal vias or copper pours; adding thermal relief or copper mass reduces RJA significantly and improves sustained power handling.
Does the 1SMA26AT3 meet RoHS and lead-free requirements?
Yes-the 1SMA26AT3G suffix denotes the Pb-free, RoHS-compliant version of the 1SMA26AT3. It uses the same die and electrical specifications as the standard part, with identical VRWM, VBR, VC, and surge ratings. The "G" variant is fully drop-in compatible in reflow soldering processes.
How does the 1SMA26AT3 compare to MOV-based protection in 24 V systems?
The 1SMA26AT3 provides tighter voltage tolerance (±5% VBR), faster response (<1 ns vs. ~25 ns for MOVs), and no degradation after repeated surges-unlike MOVs, which wear out. While MOVs offer higher energy absorption, the 1SMA26AT3 excels in precision clamping for sensitive electronics where let-through voltage must stay below 45 V, such as in automotive MCU power domains.
1SMA26AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 26V
- Voltage - Breakdown (Min):
- 28.9V
- Voltage - Clamping (Max) @ Ipp:
- 42.1V
- Current - Peak Pulse (10/1000µs):
- 9.5A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 460pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA26AT3 FAQ
1.How can I place an order for 1SMA26AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA26AT3 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 1SMA26AT3 reliable?
The price and inventory of 1SMA26AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA26AT3 is usually 5 days.
3.What payment methods are accepted for 1SMA26AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA26AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA26AT3?
1SMA26AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA26AT3 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 1SMA26AT3?
For technical support, including 1SMA26AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA26AT3 requirements.
6.How does Aetrix verify that 1SMA26AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMA26AT3 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 1SMA26AT3 meets industry standards.
7.What is the process for return or replacement of 1SMA26AT3?
All 1SMA26AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA26AT3, 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 1SMA26AT3 part is unused and in its original packaging.
Return procedure for 1SMA26AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA26AT3 Tags
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onsemi
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