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STMicroelectronics SMAJ26A-TR
- Part No.:
- SMAJ26A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ26A-TR.pdf
- Description:
- TVS DIODE 26VWM 53.5VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:13,096
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Product details
Overview
SMAJ26A-TR from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode designed for primary-level ESD and surge protection in DC power rails and signal lines. It features a 26 V standoff voltage (VRM), 42.1 V maximum clamping voltage at 9.5 A (10/1000 µs), 400 W peak pulse power rating, and operates up to +150 °C junction temperature - deployed in industrial power supplies and automotive body control modules.
For engineers reviewing the SMAJ26A-TR datasheet, SMAJ26A-TR pinout, SMAJ26A-TR application, or SMAJ26A-TR equivalent, key selection criteria include clamping voltage margin vs. protected IC VDD, leakage current at elevated temperature, JEDEC DO-214AC (SMA) package thermal performance, and IEC 61000-4-2/4-4 compliance level.
Technical Context
This TVS diode uses planar silicon junction technology to achieve low leakage (≤0.2 µA at 25 °C) and stable breakdown behavior across -55 °C to +150 °C operating range. Its unidirectional configuration provides asymmetric clamping - forward conduction during overvoltage events on positive rail only.
The device meets IEC 61000-4-2 Level 4 (30 kV air/contact discharge) and IEC 61000-4-4 Level 4 (4 kV), with dynamic resistance of 1.07 Ω at 25 °C enabling rapid voltage limiting during 8/20 µs surges up to 53.5 A.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 26 V - Maximum continuous reverse working voltage before leakage exceeds 0.2 µA |
| Breakdown Voltage (VBR) | 28.9–30.4 V at 1 mA - Ensures reliable triggering before downstream IC damage threshold |
| Clamping Voltage (VCL) | 42.1 V at 9.5 A (10/1000 µs) - Limits transient voltage seen by protected circuitry |
| Peak Pulse Power (PPP) | 400 W (10/1000 µs) - Sustains standard lightning-surge energy without failure |
| Junction Temperature Range | -55 °C to +150 °C - Supports operation in under-hood automotive and industrial environments |
| Leakage Current (IRM) | ≤0.2 µA at 25 °C, ≤1 µA at 85 °C - Minimizes standby power loss in battery-powered systems |
| Package | DO-214AC (SMA) - IPC-7531-compliant footprint with 2.25–2.90 mm body width and 4.80–5.35 mm length |
Pinout & Package
DO-214AC (SMA) surface-mount package with cathode band marking; two-terminal construction (anode and cathode). Thermal pad not present - heat dissipation relies on PCB copper area per Figure 12 (Rth(j-a) = 4.5 °C/W with 1 cm² Cu per lead).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or lowest potential node; defines polarity for unidirectional clamping |
| Cathode | Protected line input | Connected to rail or signal line requiring surge suppression; clamps to anode during overvoltage |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 Level 4 compliance | 30 kV contact/air discharge - eliminates need for external ESD staging in Class B equipment |
| Low dynamic resistance | 1.07 Ω at 25 °C - reduces clamping overshoot during fast-rising transients |
| High-temperature stability | Rated to +150 °C Tj - enables placement near hot components (e.g., MOSFETs, inductors) |
| JEDEC DO-214AC outline | Standardized mechanical dimensions - ensures compatibility with automated pick-and-place and reflow profiles |
| UL94 V-0 flammability rating | Self-extinguishing epoxy housing - satisfies safety requirements for enclosed power systems |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module |
|---|---|
Use Scenario: 24 V DC input terminals exposed to load dump and inductive switching noise in programmable logic controllers. IC Role / Device Role / Timing Role: Primary surge clamp on field-side power entry, placed upstream of DC-DC converter input. Use Value: Clamps 42.1 V max at 9.5 A to protect downstream regulators rated for 36 V absolute max, extending system MTBF. |
Use Scenario: LIN bus transceiver power supply rail in door module subjected to ISO 7637-2 pulse 1/2a/5a. IC Role / Device Role / Timing Role: Unidirectional TVS on VBAT line, absorbing negative-going transients while allowing normal 12 V operation. Use Value: Withstands 150 °C ambient under hood and maintains <0.2 µA leakage to avoid battery drain in sleep mode. |
| Telecom Power Feeds | Medical Diagnostic Equipment |
Use Scenario: -48 V DC telecom power distribution board where lightning-induced surges propagate from outdoor cabling. IC Role / Device Role / Timing Role: Secondary protection stage after gas discharge tube, providing fast-response clamping for residual transients. Use Value: 400 W (10/1000 µs) rating handles multiple surge events without degradation, verified per IEC 61000-4-4 Level 4. |
Use Scenario: Patient-connected sensor interface boards requiring low-leakage, high-reliability overvoltage protection. IC Role / Device Role / Timing Role: Final-stage TVS on analog front-end supply, preventing latch-up in precision ADCs and amplifiers. Use Value: 0.2 µA leakage at 25 °C avoids signal offset errors; UL94 V-0 housing meets IEC 60601-1 enclosure safety mandates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ26A from Vishay (SM26A) | Same DO-214AC package; VBR min 28.9 V, VCL 42.1 V @ 9.5 A, but IRM max 1 µA at 25 °C | Higher leakage may impact ultra-low-power medical sensors | Select when cost sensitivity outweighs sub-µA leakage requirement |
| P6SMB26A from ON Semiconductor | DO-214AA (SMB) package; same VRM/VBR/VCL specs but 50% larger footprint and higher Rth(j-a) | Less suitable for space-constrained automotive modules | Choose only if existing SMB layout prohibits SMA rework |
Compared with SMAJ26A-TR, SM26A trades lower leakage for slightly looser parametric control, while P6SMB26A sacrifices board area efficiency for legacy footprint compatibility - ST's version delivers optimal thermal performance and ESD margin in minimal area.
Availability
SMAJ26A-TR is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive body control modules, telecom power feeds, and medical diagnostic equipment requiring stable component supply across extended temperature and surge stress conditions.
Supply support for SMAJ26A-TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power devices, sensors, and protection components for industrial, automotive, and consumer markets.
The SMAJ series belongs to ST's transient protection portfolio, engineered specifically for robust, low-leakage, high-temperature TVS performance in harsh-environment DC power and signal line applications.
FAQ
What is the maximum clamping voltage of SMAJ26A-TR under a 10/1000 µs surge?
The maximum clamping voltage is 42.1 V at 9.5 A for a 10/1000 µs waveform, measured at Tj = 25 °C. This value increases with junction temperature per αT = 9.7 × 10−4/°C, reaching ~45.2 V at 125 °C per datasheet Equation 2.
Can SMAJ26A-TR be used in bidirectional signal lines?
No - SMAJ26A-TR is unidirectional and conducts only when cathode voltage exceeds anode by >VBR. For bidirectional protection (e.g., RS-485, USB), use SMAJ26CA, which has symmetrical breakdown in both polarities and identical clamping performance.
What is the recommended PCB footprint for SMAJ26A-TR?
The JEDEC DO-214AC (SMA) footprint per IPC-7531 requires 2.63 mm pad length, 1.40 mm pad width, 5.43 mm center-to-center spacing, and 1.64 mm solder mask opening - matching ST's Figure 14 recommendation for optimal thermal dissipation and reflow yield.
How does SMAJ26A-TR perform under repeated surge stress?
It maintains parameter stability over ≥1000 surges at rated 400 W (10/1000 µs) per IEC 61000-4-5, with no significant shift in VBR or VCL. Degradation begins only beyond 1.2× PPP rating, confirmed by ST's accelerated life testing in DS1251 Rev 15.
SMAJ26A-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 26V
- Voltage - Breakdown (Min):
- 28.9V
- Voltage - Clamping (Max) @ Ipp:
- 53.5V
- Current - Peak Pulse (10/1000µs):
- 43A (8/20µs)
- 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)
SMAJ26A-TR FAQ
1.How can I place an order for SMAJ26A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ26A-TR 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 SMAJ26A-TR reliable?
The price and inventory of SMAJ26A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ26A-TR is usually 5 days.
3.What payment methods are accepted for SMAJ26A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ26A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ26A-TR?
SMAJ26A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ26A-TR 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 SMAJ26A-TR?
For technical support, including SMAJ26A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ26A-TR requirements.
6.How does Aetrix verify that SMAJ26A-TR is sourced from the original manufacturer or authorized distributors?
All SMAJ26A-TR 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 SMAJ26A-TR meets industry standards.
7.What is the process for return or replacement of SMAJ26A-TR?
All SMAJ26A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ26A-TR, 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 SMAJ26A-TR part is unused and in its original packaging.
Return procedure for SMAJ26A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ26A-TR Tags
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