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STMicroelectronics SMAJ15A-TR
- Part No.:
- SMAJ15A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ15A-TR.pdf
- Description:
- TVS DIODE 15VWM 32.5VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:28,028
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Product details
Overview
SMAJ15A-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 15 V standoff voltage (VRM), 24.4 V clamping voltage at 16.4 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 SMAJ15A-TR datasheet, SMAJ15A-TR pinout, SMAJ15A-TR application, or SMAJ15A-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 @ 25 °C, 1 µA @ 85 °C) and stable breakdown behavior across its operating temperature range (–55 °C to +150 °C). Its unidirectional configuration provides asymmetrical clamping-forward conduction during negative transients and reverse avalanche clamping above 16.7 V.
The device complies with IEC 61000-4-2 Level 4 (30 kV air/contact discharge) and IEC 61000-4-4 Level 4 (4 kV), with dynamic resistance of 0.361 Ω at 25 °C enabling fast response to sub-microsecond surges. Its DO-214AC package supports IPC-7531-compliant footprints and meets J-STD-020 MSL Level 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Standoff Voltage (VRM) | 15 V - Maximum continuous reverse working voltage before significant leakage begins; sets minimum system rail compatibility. |
| Breakdown Voltage (VBR min) | 16.7 V @ 1 mA - Guaranteed avalanche onset threshold; ensures reliable triggering before downstream IC damage. |
| Clamping Voltage (VCL) | 24.4 V @ 16.4 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge; defines safe margin over 15 V rail. |
| Peak Pulse Power (PPP) | 400 W (10/1000 µs) - Sustained energy-handling capability for lightning-induced surges in industrial environments. |
| Leakage Current (IRM) | 0.2 µA @ 25 °C - Minimal parasitic loading on high-impedance sensor or reference circuits. |
| Junction Temperature Range | –55 °C to +150 °C - Enables deployment in under-hood automotive or enclosed industrial enclosures without derating. |
| Package | DO-214AC (SMA) - Standardized surface-mount outline with 5.35 mm × 4.60 mm footprint; compatible with automated assembly and IPC-7531 land patterns. |
Pinout & Package
DO-214AC (SMA) package: molded plastic case with two coplanar gull-wing leads; cathode indicated by band marking; JEDEC registered outline per DS1251 Rev 15.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Low-side connection point | Connected to ground or return path; conducts forward current during negative transients. |
| Cathode (K) | High-side connection point | Connected to protected line (e.g., 15 V rail); avalanches in reverse to clamp positive surges. |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 Level 4 ESD protection | 30 kV air/contact discharge - eliminates need for external ESD suppressors in USB, CAN, or sensor interfaces. |
| Low-temperature coefficient (αT) | 8.8 × 10⁻⁴ /°C - minimal VBR drift over temperature, ensuring consistent clamping across automotive thermal cycles. |
| Planar junction construction | Enables <1 µA leakage at 85 °C - critical for battery-powered IoT nodes where standby current must be minimized. |
| JEDEC DO-214AC mechanical standardization | Guarantees solder joint reliability and board-level thermal dissipation via defined lead geometry and thermal pad layout. |
| UL94 V0 flammability rating | Self-extinguishing epoxy housing - satisfies safety requirements for industrial control panels and medical power supplies. |
Applications
| Industrial Power Input Protection | Automotive Body Control Module (BCM) |
|---|---|
|
Use Scenario: 24 V DC input stage of programmable logic controller (PLC) power supply exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Primary surge shunt element placed upstream of DC-DC converter input capacitor. Use Value: Clamps 400 W transients to ≤24.4 V, preventing overvoltage stress on 36 V-rated input MOSFETs and enabling single-stage protection architecture. |
Use Scenario: LIN bus line protection in door module against ESD events during assembly and service. IC Role / Device Role / Timing Role: Unidirectional TVS tied between LIN line and chassis ground. Use Value: Withstands 30 kV contact discharge while adding <1 pF capacitance, preserving LIN signal integrity up to 20 kbps. |
| Smart Meter Voltage Rail Protection | POS Terminal Serial Interface Protection |
|
Use Scenario: 15 V auxiliary rail in utility smart meter subjected to induced surges from nearby lightning strikes. IC Role / Device Role / Timing Role: Standoff-clamp TVS parallel to rail, sized to absorb 10/1000 µs surges without thermal runaway. Use Value: 0.2 µA leakage at 25 °C avoids measurable impact on metrology ADC reference stability over 15-year field life. |
Use Scenario: RS-232 interface lines in retail point-of-sale terminal exposed to user-handling ESD. IC Role / Device Role / Timing Role: Discrete TVS on TX/RX lines referenced to local ground plane. Use Value: 24.4 V clamping voltage maintains margin below MAX3232 absolute maximum ratings (±30 V), eliminating latch-up risk. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ15A from Vishay (SM8S15A) | Higher PPP (6600 W @ 10/1000 µs), higher VCL (27.7 V @ 14.4 A), larger DO-218AB package | Better suited for high-energy automotive load dump; less suitable for space-constrained PCBs | Select when surge energy exceeds 400 W but board area allows larger footprint |
| P6SMB15A from ON Semiconductor | Same DO-214AC package, identical VRM/VBR, but higher IRM (1 µA @ 25 °C) and lower Tj max (175 °C) | Acceptable for commercial-grade designs; not recommended for extended high-temp operation | Choose only if cost sensitivity outweighs leakage and thermal margin requirements |
Compared with SMAJ15A-TR, SM8S15A offers superior surge handling at the expense of board space and clamping voltage margin, while P6SMB15A trades leakage and thermal robustness for lower unit cost-making SMAJ15A-TR optimal for thermally demanding, low-leakage industrial applications.
Availability
SMAJ15A-TR is available at Aetrix Electronics and suitable for industrial power input protection, automotive body control modules, smart meter voltage rail protection, and POS terminal serial interface protection requiring stable component supply and full traceability.
Supply support for SMAJ15A-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 analog ICs for industrial, automotive, and consumer markets.
The SMAJ series belongs to ST's transient protection portfolio, engineered specifically for robust, standardized ESD/surge suppression in space- and thermal-constrained surface-mount applications-emphasizing low leakage, high-temperature stability, and international EMC compliance.
FAQ
What is the maximum clamping voltage of SMAJ15A-TR under a 10/1000 µs surge?
The maximum clamping voltage is 24.4 V at 16.4 A for a 10/1000 µs waveform, measured at Tj = 25 °C. This value increases with junction temperature per αT = 8.8 × 10⁻⁴ /°C, reaching ~26.1 V at 125 °C using the formula VCL(Tj) = VCL(25 °C) × [1 + αT × (Tj – 25)].
Is SMAJ15A-TR bidirectional or unidirectional?
SMAJ15A-TR is unidirectional: it functions as a standard avalanche diode with cathode marked by a band, conducting forward current during negative transients and clamping positive surges above VBR. The "A" suffix denotes unidirectional; "CA" indicates bidirectional variants like SMAJ15CA.
Does SMAJ15A-TR meet automotive qualification standards?
While not AEC-Q200 qualified, SMAJ15A-TR meets IEC 61000-4-2 Level 4 (30 kV ESD) and IEC 61000-4-4 Level 4 (4 kV surge), and operates up to 150 °C junction temperature-enabling use in non-safety-critical automotive subsystems such as body electronics, provided system-level validation confirms robustness.
What is the thermal resistance (Rth(j-a)) of SMAJ15A-TR on a standard FR4 PCB?
On a 70 µm copper FR4 board with recommended IPC-7531 footprint (1.40 mm × 5.43 mm pads), Rth(j-a) is approximately 120 °C/W for a single pulse. With 2 cm² total copper area under both leads, this improves to ~3.5 °C/W-critical for sustaining repeated surge events without thermal runaway.
SMAJ15A-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):
- 15V
- Voltage - Breakdown (Min):
- 16.7V
- Voltage - Clamping (Max) @ Ipp:
- 32.5V
- Current - Peak Pulse (10/1000µs):
- 71A (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)
SMAJ15A-TR FAQ
1.How can I place an order for SMAJ15A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ15A-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 SMAJ15A-TR reliable?
The price and inventory of SMAJ15A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ15A-TR is usually 5 days.
3.What payment methods are accepted for SMAJ15A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ15A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ15A-TR?
SMAJ15A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ15A-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 SMAJ15A-TR?
For technical support, including SMAJ15A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ15A-TR requirements.
6.How does Aetrix verify that SMAJ15A-TR is sourced from the original manufacturer or authorized distributors?
All SMAJ15A-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 SMAJ15A-TR meets industry standards.
7.What is the process for return or replacement of SMAJ15A-TR?
All SMAJ15A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ15A-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 SMAJ15A-TR part is unused and in its original packaging.
Return procedure for SMAJ15A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMAJ15A-TR Tags
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