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STMicroelectronics SMAJ154A-TR
- Part No.:
- SMAJ154A-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
SMAJ154A-TR.pdf
- Description:
- TVS DIODE 154VWM 317VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:11,363
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Product details
Overview
SMAJ154A-TR from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode designed for primary-level surge protection in DC power rails and signal lines. It features a 154 V stand-off voltage (VRM), 246 V maximum clamping voltage (VCL) at 1.6 A peak pulse current (IPP), 400 W peak pulse power (10/1000 µs), and operates up to +150 °C junction temperature - deployed in industrial power supplies, telecom interface circuits, and automotive body control modules.
For engineers reviewing the SMAJ154A-TR datasheet, SMAJ154A-TR pinout, SMAJ154A-TR application, or SMAJ154A-TR equivalent, key selection criteria include clamping voltage margin vs. protected IC VMAX, leakage current at elevated temperature, JEDEC DO-214AC (SMA) package thermal performance, and IEC 61000-4-2/4-4 compliance level.
Technical Context
This unidirectional TVS diode uses planar silicon junction technology to achieve low leakage (≤0.2 µA at 25 °C, ≤1 µA at 85 °C) and stable breakdown behavior across -55 °C to +150 °C operating range. Its dynamic resistance (RD = 18.3 Ω) and temperature coefficient (αT = 10.8 × 10−4/°C) enable predictable clamping voltage shift with junction temperature.
The device complies with IEC 61000-4-2 Level 4 (30 kV air/contact discharge) and IEC 61000-4-4 Level 4 (4 kV), meeting MIL-STD-883 Method 3015 ESD requirements. Its SMA package meets IPC-7531 footprint standards and J-STD-020 MSL Level 1, supporting lead-free reflow up to 245 °C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 154 V - Maximum continuous reverse working voltage before avalanche conduction begins. |
| Breakdown Voltage (VBR) | 171–180 V at 1 mA - Confirmed minimum/maximum avalanche onset threshold under DC test conditions. |
| Clamping Voltage (VCL) | 246 V at 1.6 A (10/1000 µs) - Peak voltage seen by protected circuit during specified surge event. |
| Peak Pulse Power (PPP) | 400 W (10/1000 µs) - Sustained surge energy handling capability without degradation. |
| Leakage Current (IRM) | ≤0.2 µA at 25 °C, ≤1 µA at 85 °C - Ensures minimal standby power loss and signal integrity in high-impedance nodes. |
| Junction Temperature Range | -55 °C to +150 °C - Validated operation in under-hood automotive, industrial motor drives, and outdoor telecom enclosures. |
| Dynamic Resistance (RD) | 18.3 Ω - Determines VCL rise slope under increasing surge current; critical for precision clamping design. |
Pinout & Package
The SMAJ154A-TR is housed in a JEDEC DO-214AC (SMA) surface-mount package with two terminals: Cathode (marked band) and Anode. The package measures 4.80–5.35 mm (E) × 2.25–2.90 mm (D) × 0.75–1.50 mm (L), with matte tin-plated leads compliant with JESD-22-B102 E3 and MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Surge current sink node | Connected to protected line; conducts avalanche current to ground during overvoltage events. |
| Anode | Reference/ground return path | Typically tied to system ground or low-impedance return plane; completes surge current loop. |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 Level 4 ESD immunity | 30 kV contact/air discharge - Eliminates need for secondary ESD protection on board-level interfaces. |
| Low-temperature-coefficient clamping | αT = 10.8 × 10−4/°C - Enables accurate VCL prediction across full operating temperature range. |
| High-reliability planar junction | 150 °C max Tj, MSL Level 1 - Supports long-term stability in thermally stressed environments without derating. |
| Controlled dynamic resistance | RD = 18.3 Ω - Allows precise modeling of VCL vs. IPP for PCB-level surge margin analysis. |
Applications
| Industrial Power Supply Protection | Telecom Line Interface |
|---|---|
|
Use Scenario: 24 V DC input rail in programmable logic controller (PLC) power module exposed to inductive switching transients. IC Role / Device Role / Timing Role: Primary surge clamp placed upstream of DC-DC converter input, absorbing 400 W surges within 1 ms. Use Value: Limits voltage excursion to ≤246 V, preventing damage to 36 V-rated input capacitors and MOSFET gate drivers. |
Use Scenario: RS-485 data line in base station remote radio unit subjected to lightning-induced surges. IC Role / Device Role / Timing Role: Unidirectional TVS on differential pair, referenced to local ground, activated within <1 ns of overvoltage onset. Use Value: Clamps common-mode transients to safe levels while maintaining <1 pF junction capacitance impact on signal integrity at 10 Mbps. |
| Automotive Body Control Module | Smart Meter Power Input |
|
Use Scenario: 12 V battery feed to BCM microcontroller supply, vulnerable to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: First-line protection element between fuse and LDO regulator, rated for 150 °C ambient operation. Use Value: Withstands 125 °C under-hood temperatures with ≤1 µA leakage, avoiding false resets or brownouts. |
Use Scenario: AC/DC adapter input stage in utility smart meter exposed to grid switching surges. IC Role / Device Role / Timing Role: Standoff-rated TVS across bulk capacitor input, coordinated with MOV and fuse for staged protection. Use Value: Provides precise 154 V hold-off to avoid nuisance triggering during 110–240 VAC line fluctuations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ150A-TR | 150 V VRM, 243 V VCL at 1.6 A, RD = 17.5 Ω | Lower stand-off allows tighter margin near 150 V systems but reduces noise immunity. | Select when system nominal voltage is ≤150 V and clamping margin must be minimized. |
| SMAJ160A-TR | 160 V VRM, 256 V VCL at 1.6 A, RD = 19.2 Ω | Higher VRM improves noise immunity but increases VCL, risking overvoltage on downstream 200 V-rated components. | Prefer where input transients exceed 154 V but protected ICs tolerate ≥256 V clamping. |
Compared with SMAJ150A-TR and SMAJ160A-TR, SMAJ154A-TR offers optimal balance for 154 V nominal systems-delivering exact VRM alignment, lowest VCL among adjacent ratings, and verified thermal stability at 150 °C junction temperature.
Availability
SMAJ154A-TR is available at Aetrix Electronics and suitable for industrial power supply protection, telecom line interface hardening, automotive body control modules, and smart meter power input stages requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for SMAJ154A-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 analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.
The SMAJ series belongs to ST's Transient Voltage Suppressor portfolio, engineered specifically for robust, low-leakage, high-temperature surge protection in space-constrained surface-mount applications demanding IEC/EN/MIL compliance.
FAQ
What is the maximum clamping voltage of SMAJ154A-TR under a 10/1000 µs surge?
The maximum clamping voltage (VCL) is 246 V at 1.6 A peak pulse current for a 10/1000 µs waveform, measured per IEC 61000-4-5 test conditions. This value is guaranteed across the full operating temperature range (-55 °C to +150 °C) and defines the upper voltage limit imposed on protected circuitry during standardized surge events.
Is SMAJ154A-TR unidirectional or bidirectional, and how is polarity identified?
SMAJ154A-TR is a unidirectional TVS diode, intended for DC line protection where reverse voltage is not expected. Polarity is marked by a cathode band on the SMA package body; the banded end connects to the line being protected, while the anode connects to ground or reference potential.
Does SMAJ154A-TR meet lead-free reflow requirements?
Yes - SMAJ154A-TR uses matte tin-plated leads compliant with J-STD-020 MSL Level 1 and supports lead-free reflow profiles up to 245 °C peak temperature for 20–30 seconds, per STMicroelectronics' recommended profile (DS1251 Rev 15, Figure 21).
How does leakage current change with temperature for SMAJ154A-TR?
Leakage current (IRM) is ≤0.2 µA at 25 °C and rises to ≤1 µA at 85 °C, as specified in Table 2 of DS1251. This low, well-characterized drift ensures minimal impact on high-impedance sensor inputs or battery-backed circuits across automotive and industrial temperature ranges.
SMAJ154A-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):
- 154V
- Voltage - Breakdown (Min):
- 171V
- Voltage - Clamping (Max) @ Ipp:
- 317V
- Current - Peak Pulse (10/1000µs):
- 7A (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)
SMAJ154A-TR FAQ
1.How can I place an order for SMAJ154A-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for SMAJ154A-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 SMAJ154A-TR reliable?
The price and inventory of SMAJ154A-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMAJ154A-TR is usually 5 days.
3.What payment methods are accepted for SMAJ154A-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMAJ154A-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMAJ154A-TR?
SMAJ154A-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMAJ154A-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 SMAJ154A-TR?
For technical support, including SMAJ154A-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMAJ154A-TR requirements.
6.How does Aetrix verify that SMAJ154A-TR is sourced from the original manufacturer or authorized distributors?
All SMAJ154A-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 SMAJ154A-TR meets industry standards.
7.What is the process for return or replacement of SMAJ154A-TR?
All SMAJ154A-TR units undergo pre-shipment inspection (PSI). If there is an issue with SMAJ154A-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 SMAJ154A-TR part is unused and in its original packaging.
Return procedure for SMAJ154A-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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