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STMicroelectronics SMAJ100A-TR
- Part No.:
- SMAJ100A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ100A-TR.pdf
- Description:
- TVS DIODE 100VWM 212VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:457
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Product details
Overview
SMAJ100A-TR from STMicroelectronics is a unidirectional 400 W transient voltage suppression diode designed for primary-level ESD and surge protection on DC power rails and signal lines. It features a 100 V stand-off voltage (VRM), 162 V clamping voltage at 2.5 A (10/1000 µs), 15.7 A peak pulse current, and operates up to 150 °C junction temperature-used in industrial power supplies and telecom interface protection.
For engineers reviewing the SMAJ100A-TR datasheet, SMAJ100A-TR pinout, SMAJ100A-TR application, or SMAJ100A-TR equivalent, key selection criteria include clamping voltage margin vs. protected IC VMAX, leakage current at elevated temperature, thermal resistance under PCB copper area constraints, and IEC 61000-4-2/4-4 compliance level.
Technical Context
This TVS diode uses planar silicon junction technology to achieve low leakage (≤1 µA at 85 °C) and stable breakdown characteristics across -55 °C to +150 °C operating range. Its unidirectional configuration provides asymmetric clamping-forward conduction only during negative transients-making it suitable for DC-biased lines where reverse polarity stress is absent.
The device complies with IEC 61000-4-2 (30 kV air/contact discharge) and IEC 61000-4-4 Level 4 (4 kV), with dynamic resistance of 8.1 Ω at 10/1000 µs. Clamping voltage scales linearly with junction temperature via αT = 10.7 × 10−4/°C, enabling accurate worst-case VCL calculation at Tj = 150 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 100 V - maximum continuous reverse working voltage before significant leakage or breakdown |
| Breakdown Voltage (VBR) | 111–117 V at 1 mA - ensures reliable triggering above normal rail voltage with margin |
| Clamping Voltage (VCL) | 162 V at 2.5 A (10/1000 µs) - limits transient voltage seen by downstream circuitry |
| Peak Pulse Power (PPP) | 400 W (10/1000 µs) - sustains standard lightning-surge energy without failure |
| Leakage Current (IRM) | 0.2 µA at 25 °C, 1 µA at 85 °C - preserves low-power standby integrity |
| Junction Temperature Range | -55 °C to +150 °C - supports operation in harsh industrial or automotive under-hood environments |
| Dynamic Resistance (RD) | 8.1 Ω - determines VCL rise per additional ampere of surge current beyond rated IPP |
Pinout & Package
SMAJ100A-TR is housed in an industry-standard SMA (DO-214AC) surface-mount package per IPC-7531 footprint, with matte tin-plated leads compliant with J-STD-002 and MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked band) | Transient current sink | Connected to protected line; conducts surge current to ground when VAK > VBR |
| Anode | Reference node / ground return | Typically tied to system ground or low-impedance return path for effective clamping |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 Level 4 compliance | 30 kV contact/air discharge - exceeds industrial immunity requirements without external filtering |
| Low-temperature coefficient | αT = 10.7 × 10−4/°C - enables precise VCL prediction across full operating range |
| JEDEC DO-214AC package | Standardized thermal and mechanical interface - ensures consistent solder joint reliability and board-level thermal dissipation |
| Planar junction construction | Enables <1 µA leakage at 85 °C - critical for battery-backed or ultra-low-power monitoring circuits |
Applications
| Industrial PLC I/O Protection | Telecom Line Interface |
|---|---|
Use Scenario: 24 V DC input channels on programmable logic controllers exposed to field wiring surges and ESD events. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed between terminal block and input conditioning circuitry. Use Value: Limits transients to ≤162 V, protecting downstream op-amps and ADC front-ends rated for 180 V absolute max. | Use Scenario: RS-485 data lines in outdoor base stations subject to induced lightning surges. IC Role / Device Role / Timing Role: Unidirectional shunt protector on VCC-biased differential pair, referenced to local ground. Use Value: Clamps common-mode surges within 1 ns response time while maintaining <1 pF capacitance impact on signal integrity. |
| DC Power Rail Protection | Automotive Body Control Module |
Use Scenario: 12–48 V supply inputs in industrial HMIs and motor drives subjected to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Standoff-rated TVS placed upstream of DC-DC converters and LDOs. Use Value: Absorbs 400 W (10/1000 µs) without degradation, preserving converter enable thresholds and feedback stability. | Use Scenario: 12 V auxiliary power inputs in BCMs exposed to jump-start transients and alternator load dump. IC Role / Device Role / Timing Role: Unidirectional clamp referenced to chassis ground, co-located with fuse and filter inrush stage. Use Value: Withstands 150 °C ambient and maintains <1 µA leakage at 85 °C junction, ensuring long-term reliability in sealed enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ100AHE3/5BT | Same electrical specs; AEC-Q200 qualified, halogen-free, RoHS-compliant variant | Required for automotive production; higher traceability and qualification documentation | Select for automotive-grade programs requiring PPAP and lot traceability |
| P6SMB100A | Same VRM/VBR/VCL but 600 W PPP rating (10/1000 µs); larger SMB package (DO-214AA) | Higher surge margin needed; PCB space allows larger footprint | Choose when legacy layout accommodates SMB or surge requirement exceeds 400 W |
Compared with SMAJ100AHE3/5BT, the SMAJ100A-TR lacks AEC-Q200 qualification but offers identical electrical performance at lower cost for industrial use; versus P6SMB100A, it trades 200 W extra pulse power for 30% smaller PCB area and lower thermal resistance on standard FR4.
Availability
SMAJ100A-TR is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and automotive body electronics requiring stable component supply with no minimum order quantity for prototyping and low-volume production.
Supply support for SMAJ100A-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, delivering intelligent power, analog, MEMS, and microcontroller solutions across industrial, automotive, and consumer markets.
The SMAJ series belongs to ST's transient protection portfolio, engineered specifically for high-reliability DC rail and interface protection where low leakage, tight VBR tolerance, and JEDEC-standard packaging are mandatory.
FAQ
What is the maximum clamping voltage of SMAJ100A-TR under a 10/1000 µs surge?
The maximum clamping voltage is 162 V at 2.5 A for a 10/1000 µs waveform, measured at Tj = 25 °C. At elevated junction temperatures, VCL increases linearly using αT = 10.7 × 10−4/°C, reaching ~172 V at Tj = 150 °C.
Can SMAJ100A-TR be used in bidirectional signal lines?
No - SMAJ100A-TR is unidirectional and conducts only in reverse bias. For bidirectional protection (e.g., USB, RS-485), the SMAJ100CA-TR variant must be used, which provides symmetrical clamping for both polarities.
What PCB copper area is recommended to maintain Tj ≤ 150 °C during surge events?
Per Figure 12 in DS1251, ≥2.5 cm² of 70 µm copper under each lead reduces Rth(j-a) to ~2.5 °C/W. With 400 W pulse power, this limits ΔT to ~1000 °C·W × 2.5 °C/W = 250 °C rise - but since pulse duration is short (<1 ms), actual Tj rise remains within safe limit if average power is managed.
Does SMAJ100A-TR meet UL 94 V-0 flammability requirements?
Yes - the SMA package meets UL 94 V-0 per the datasheet, confirmed by ST's ECOPACK environmental compliance documentation. This applies to the molded epoxy body material, not the metallization or leads.
SMAJ100A-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AC, SMA
- Series:
- SMAJ, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 100V
- Voltage - Breakdown (Min):
- 111V
- Voltage - Clamping (Max) @ Ipp:
- 212V
- Current - Peak Pulse (10/1000µs):
- 11A (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)
SMAJ100A-TR FAQ
1.How can I place an order for SMAJ100A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ100A-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 SMAJ100A-TR reliable?
The price and inventory of SMAJ100A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ100A-TR is usually 5 days.
3.What payment methods are accepted for SMAJ100A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ100A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ100A-TR?
SMAJ100A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ100A-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 SMAJ100A-TR?
For technical support, including SMAJ100A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ100A-TR requirements.
6.How does Aetrix verify that SMAJ100A-TR is sourced from the original manufacturer or authorized distributors?
All SMAJ100A-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 SMAJ100A-TR meets industry standards.
7.What is the process for return or replacement of SMAJ100A-TR?
All SMAJ100A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ100A-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 SMAJ100A-TR part is unused and in its original packaging.
Return procedure for SMAJ100A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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