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STMicroelectronics STIEC45-28AS
- Part No.:
- STIEC45-28AS
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
STIEC45-28AS.pdf
- Description:
- TVS DIODE 28VWM 49VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:5,232
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Product details
Overview
STIEC45-28AS from STMicroelectronics is a unidirectional Transil™ TVS diode designed for IEC 61000-4-5 Level 4 surge protection on DC power lines, with 28 V stand-off voltage, 32.6 V typical breakdown voltage at 1 mA, 49 V clamping voltage at 500 A (8/20 μs), and 0.2 μA leakage at 25 °C. It operates up to 150 °C junction temperature and is packaged in JEDEC-registered SMC (DO-214AB) for industrial power supply and telecom interface protection.
For engineers reviewing the STIEC45-28AS datasheet, STIEC45-28AS pinout, STIEC45-28AS application, or STIEC45-28AS equivalent, key selection criteria include clamping performance at 500 A surge, thermal resistance (15 °C/W junction-to-leads), low leakage stability across temperature, and SMC footprint compatibility with IPC 7351-recommended pad layout.
Technical Context
The STIEC45-28AS uses planar silicon technology to achieve stable reverse breakdown at 31.1–34.3 V and precise clamping behavior governed by dynamic resistance (0.029 Ω) and temperature coefficient (9.8 × 10⁻⁴ /°C). Its unidirectional architecture provides forward conduction near 0.6 V while maintaining high impedance below VRM = 28 V.
It meets IEC 61000-4-2 Level 4 ESD immunity (15 kV air / 8 kV contact), IEC 61000-4-4 EFT robustness, and MIL-STD-883G HBM (25 kV), with thermal design enabled by Rth(j-l) = 15 °C/W and Rth(j-a) = 90 °C/W on recommended copper layout.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 28 V - Maximum continuous reverse operating voltage before clamping begins |
| Breakdown Voltage (VBR) | 31.1–34.3 V at 1 mA - Ensures reliable triggering margin above VRM under temperature variation |
| Clamping Voltage (VCL) | 49 V at 500 A (8/20 μs) - Limits transient energy delivered to protected circuitry |
| Peak Pulse Current (Ipp) | 500 A (8/20 μs) - Supports IEC 61000-4-5 Level 4 common-mode surge (334 A) with safety margin |
| Leakage Current (IRM) | 0.2 μA at 25 °C - Minimizes standby power loss in high-impedance DC rails |
| Junction Temperature Range | −55 to +150 °C - Enables deployment in automotive under-hood and industrial SMPS environments |
| Dynamic Resistance (RD) | 0.029 Ω - Determines linear clamping slope; critical for predicting VCL at non-standard surge currents |
Pinout & Package
The STIEC45-28AS is housed in an SMC package (JEDEC DO-214AB), featuring two terminals: cathode (marked end) and anode. The package measures 5.55–6.25 mm × 7.75–8.15 mm × 2.45 mm max height, with gull-wing leads optimized for high-current PCB routing and thermal dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Surge current sink node | Connected to protected line; conducts during reverse transients to clamp voltage |
| Anode | Reference/ground return path | Typically tied to system ground or low-impedance return plane for effective energy diversion |
Key Features
| Feature | Design Value |
|---|---|
| High-temperature reliability | Rated for continuous operation up to Tj = 150 °C with only 410 A derated peak current - supports compact, thermally constrained designs |
| Low-temperature coefficient of VBR | αT = 9.8 × 10⁻⁴ /°C - ensures predictable clamping voltage shift across −55 to +150 °C range |
| Ultra-low leakage | ≤1 μA at 85 °C - preserves signal integrity and battery life in always-on monitoring circuits |
| JEDEC-compliant SMC footprint | DO-214AB outline with IPC 7351-recommended pad layout - enables drop-in replacement and automated assembly |
Applications
| Industrial Power Supply Protection | Telecom Interface Surge Suppression |
|---|---|
Use Scenario: Protecting 24 V DC input rails in programmable logic controllers against lightning-induced surges per IEC 61000-4-5 Level 4. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between input rail and chassis ground to shunt common-mode transients. Use Value: Clamps 500 A surges to ≤49 V, preventing damage to upstream DC/DC converters and downstream microcontrollers. | Use Scenario: Safeguarding RS-485 transceiver inputs in outdoor base stations exposed to induced surges on long cable runs. IC Role / Device Role / Timing Role: Standoff-rated TVS on differential pair lines, leveraging 28 V VRM to avoid false triggering during normal 24 V bus operation. Use Value: Maintains <0.2 μA leakage at 25 °C, eliminating bias current errors in precision termination networks. |
| Automotive Body Control Module (BCM) | Smart Meter DC Power Input |
Use Scenario: Securing 12–24 V auxiliary power inputs in BCMs subjected to load-dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Primary overvoltage clamp on main power rail, coordinated with upstream fuse and downstream LDO regulators. Use Value: Withstands 150 °C junction temperature and delivers 410 A surge capability at Tj = 150 °C - matches under-hood thermal profiles. | Use Scenario: Protecting lithium-ion backup battery charging circuitry in utility smart meters against grid-switching transients. IC Role / Device Role / Timing Role: Low-leakage TVS on 3.3 V or 5 V system rails where standby current budget is <10 μA. Use Value: Delivers 0.2 μA IRM at 25 °C and 1 μA at 85 °C - avoids measurable impact on battery runtime over 10-year field life. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ28A | Lower Ipp (400 A), higher VCL (53.3 V at 400 A), same SMC package | Limited to IEC 61000-4-5 Level 3 (2 kV) due to reduced surge margin | Select when cost sensitivity outweighs need for Level 4 compliance |
| SMCJ28A | Higher Ipp (600 A), same VRM/VBR, larger SMC package (DO-214AB variant with thicker leads) | Requires revised PCB pad layout; better suited for repeated surge events | Choose for mission-critical infrastructure where surge repetition rate exceeds 100x/hour |
Compared with SMAJ28A and SMCJ28A, the STIEC45-28AS delivers optimal balance of 500 A surge rating, 49 V clamping, and ultra-low leakage in standard SMC - making it ideal for space-constrained, thermally demanding, and battery-sensitive IEC 61000-4-5 Level 4 applications.
Availability
STIEC45-28AS is available at Aetrix Electronics and suitable for industrial power supply protection, telecom interface surge suppression, automotive body control modules, and smart meter DC power input requiring stable component supply and full IEC 61000-4-5 Level 4 compliance.
Supply support for STIEC45-28AS 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 discrete devices for industrial, automotive, and consumer markets.
The STIEC45 series belongs to ST's Transil™ TVS portfolio, engineered specifically for high-reliability DC power line protection in harsh electromagnetic environments - emphasizing low leakage, high-temperature operation, and precise clamping predictability.
FAQ
What is the maximum clamping voltage of STIEC45-28AS at 300 A (8/20 μs)?
Using the formula VCLmax = RD × IPP + VBRmax, with RD = 0.029 Ω and VBRmax = 34.3 V, the calculated clamping voltage is 42.9 V. This value aligns with the device's linear clamping behavior and is verified in Figure 4 of the datasheet for interpolated surge levels.
Can STIEC45-28AS be used in bidirectional signal lines?
No - STIEC45-28AS is unidirectional and conducts only in reverse bias. For bidirectional protection (e.g., RS-485), ST recommends STIEC45-28ACS, which clamps symmetrically in both directions with identical VBR and VCL characteristics.
Does STIEC45-28AS meet RoHS2 and REACH requirements?
Yes - the device is RoHS2 compliant (2011/65/EU) and REACH SVHC-free, as confirmed in the ECOPACK® documentation referenced in Section 2 of the datasheet. It uses lead-free terminations and halogen-free molding compound meeting UL 94 V0.
What is the recommended PCB pad layout for optimal thermal performance?
ST specifies an IPC 7351-compliant SMC footprint with minimum 4.4 cm² copper area per lead (Figure 10). Use 35 µm copper thickness and connect pads directly to internal ground/power planes via ≥4 thermal vias per lead to achieve Rth(j-a) ≈ 90 °C/W.
STIEC45-28AS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- STIEC, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 49V
- Current - Peak Pulse (10/1000µs):
- 500A (8/20µs)
- Power - Peak Pulse:
- -
- 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:
- SMC
STIEC45-28AS FAQ
1.How can I place an order for STIEC45-28AS through Aetrix?
Please submit a Request for Quotation (RFQ) for STIEC45-28AS 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 STIEC45-28AS reliable?
The price and inventory of STIEC45-28AS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STIEC45-28AS is usually 5 days.
3.What payment methods are accepted for STIEC45-28AS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STIEC45-28AS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STIEC45-28AS?
STIEC45-28AS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STIEC45-28AS 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 STIEC45-28AS?
For technical support, including STIEC45-28AS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STIEC45-28AS requirements.
6.How does Aetrix verify that STIEC45-28AS is sourced from the original manufacturer or authorized distributors?
All STIEC45-28AS 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 STIEC45-28AS meets industry standards.
7.What is the process for return or replacement of STIEC45-28AS?
All STIEC45-28AS units undergo pre-shipment inspection (PSI). If there is an issue with STIEC45-28AS, 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 STIEC45-28AS part is unused and in its original packaging.
Return procedure for STIEC45-28AS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STIEC45-28AS Tags
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