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STMicroelectronics STIEC45-33AS
- Part No.:
- STIEC45-33AS
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
STIEC45-33AS.pdf
- Description:
- TVS DIODE 33VWM 59VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:3,751
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Product details
Overview
STIEC45-33AS from STMicroelectronics is a unidirectional Transil™ TVS diode designed for IEC 61000-4-5 Level 4 surge protection on DC power lines, with 33 V stand-off voltage, 59 V max clamping voltage at 500 A (8/20 μs), 0.2 μA leakage at 25 °C, and SMC (DO-214AB) package. It operates up to 150 °C junction temperature and delivers 410 A peak pulse current at Tj = 150 °C.
For engineers reviewing the STIEC45-33AS datasheet, STIEC45-33AS pinout, STIEC45-33AS application, or STIEC45-33AS equivalent, key selection criteria include clamping performance under 4 kV common-mode surges per IEC 61000-4-5, low-leakage operation in high-temperature SMPS rails, and compatibility with IPC 7351-compliant SMC footprints.
Technical Context
The STIEC45-33AS uses planar silicon technology to achieve stable breakdown behavior and low leakage across temperature, enabling reliable transient suppression in high-reliability power supplies. Its unidirectional architecture provides forward conduction (~0.6 V) and reverse clamping starting at VBR = 36.7–40.6 V, with dynamic resistance of 0.036 Ω.
It meets IEC 61000-4-2 Level 4 ESD (15 kV air / 8 kV contact), IEC 61000-4-4 EFT, and MIL-STD-883G HBM (25 kV), while maintaining UL 94 V0 resin compliance and JEDEC-registered SMC mechanical outline.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 33 V - Maximum continuous DC operating voltage before leakage exceeds 1 μA at 85 °C |
| Breakdown Voltage (VBR) | 36.7–40.6 V at 1 mA - Confirmed reverse conduction onset range defining clamping threshold |
| Clamping Voltage (VCL) | 59 V max at 500 A, 8/20 μs - Peak voltage seen by protected circuit during worst-case surge |
| Peak Pulse Current (IPP) | 500 A (8/20 μs) at Tj = 25 °C; 410 A at Tj = 150 °C - Validated surge-handling capacity under thermal stress |
| Leakage Current (IR) | 0.2 μA at 25 °C; 1 μA at 85 °C - Enables use in low-power standby circuits without loading |
| Junction Temperature Range | −55 °C to +150 °C - Supports deployment in industrial and automotive under-hood environments |
| Dynamic Resistance (RD) | 0.036 Ω - Determines VCL rise slope (ΔV = RD × IPP + VBR) for accurate system-level clamping prediction |
Pinout & Package
The STIEC45-33AS is housed in an SMC package (JEDEC DO-214AB), with a standardized two-terminal configuration optimized for high-current PCB trace routing and thermal dissipation via copper pads per IPC 7351.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (A) | Forward conduction path | Connects to ground or low-side return; conducts ~0.6 V during positive transients |
| Cathode (K) | Reverse-biased clamping node | Connects to protected line; initiates clamping at VBR ≥ 36.7 V during negative surges |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-5 Level 4 compliance | Withstands 4 kV common-mode surge (R = 12 Ω) - eliminates need for external series impedance in telecom/data line protection |
| Low-temperature-coefficient VBR | αT = 10 × 10−4/°C - Ensures predictable clamping shift across −55 °C to +150 °C operating range |
| High-temperature surge capability | 410 A @ Tj = 150 °C - Maintains >80% of room-temp IPP, critical for enclosed power supply designs |
| UL 94 V0 resin housing | Self-extinguishing polymer - satisfies flammability requirements for Class I/II AC-DC adapters and industrial controllers |
Applications
| Industrial PLC Power Rails | Telecom DC Feeds (48 V) |
|---|---|
Use Scenario: Protection of 24–36 V DC input stages in programmable logic controllers exposed to lightning-induced surges on factory floor wiring. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between input rail and chassis ground to shunt 4 kV common-mode transients per IEC 61000-4-5. Use Value: Limits voltage excursion to ≤59 V during 500 A surge, preventing damage to upstream DC-DC controllers and isolated gate drivers. | Use Scenario: Surge suppression on −48 V telecom distribution boards where differential-mode surges reach 500 A (1 kV, R = 2 Ω). IC Role / Device Role / Timing Role: Cathode-to-rail connection enables fast clamping response (<1 ns) without adding series inductance from bidirectional layout. Use Value: Delivers 59 V clamping at full rated current, reducing overvoltage stress on hot-swap controllers and PMBus monitoring ICs. |
| Server PSU Hold-up Capacitors | Automotive Body Control Modules |
Use Scenario: Guarding bulk capacitor inputs in 33 V intermediate bus converters where leakage must remain <1 μA at 85 °C ambient. IC Role / Device Role / Timing Role: Standby-mode TVS connected across input capacitors to absorb repetitive EFT bursts without thermal runaway. Use Value: 0.2 μA leakage at 25 °C and stable 1 μA at 85 °C ensure no measurable discharge of hold-up energy during idle periods. | Use Scenario: Protecting 33 V auxiliary power domains in BCMs subjected to load-dump and jump-start transients per ISO 7637-2. IC Role / Device Role / Timing Role: Unidirectional placement (cathode to rail) blocks reverse battery connection while clamping positive spikes above 36.7 V. Use Value: 150 °C Tj rating allows direct mounting near high-power relays without derating, improving board-level thermal margin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ33A (Bourns) | Same 33 V VRM, but higher VCL = 53.3 V at 52.2 A (not 500 A); lower IPP = 52.2 A (8/20 μs) | Rated for lower-energy surges; unsuitable for IEC 61000-4-5 Level 4 (4 kV) common-mode testing | Select only for cost-sensitive, low-surge-risk consumer power supplies where 500 A capability is unnecessary |
| P6SMB33A (Littelfuse) | Identical VRM and VCL specs, but 300 A IPP (8/20 μs); 125 °C max Tj | Limited to lower-temperature environments; cannot sustain 410 A at 150 °C like STIEC45-33AS | Prefer when footprint compatibility with SMB package is required and thermal derating to 125 °C is acceptable |
Compared with SMBJ33A and P6SMB33A, the STIEC45-33AS uniquely supports full IEC 61000-4-5 Level 4 compliance at elevated junction temperatures, offering superior clamping consistency and surge margin in thermally constrained industrial power systems.
Availability
STIEC45-33AS is available at Aetrix Electronics and suitable for industrial PLC power rails, telecom DC feeds, server PSU hold-up capacitors, and automotive body control modules requiring stable component supply and long-term obsolescence management.
Supply support for STIEC45-33AS 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, specializing in power management, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.
The STIEC45 series belongs to ST's Transil™ TVS portfolio, engineered specifically for robust, high-temperature DC power line protection against IEC 61000-4-5 surges in mission-critical infrastructure equipment.
FAQ
What is the maximum clamping voltage of STIEC45-33AS at 500 A?
The maximum clamping voltage (VCL) is 59 V under 8/20 μs surge conditions at Tamb = 25 °C, as specified in Table 4 of the official datasheet (DocID16871 Rev 3). This value represents the peak voltage measured across the device terminals during full-rated surge current, ensuring downstream components see no more than this level.
Can STIEC45-33AS be used in bidirectional signal lines?
No - STIEC45-33AS is strictly unidirectional and conducts forward current (~0.6 V) from anode to cathode. For bidirectional protection, ST offers the STIEC45-33ACS variant, which clamps symmetrically in both directions. Using the AS version on AC or differential signal lines risks forward conduction during normal operation and inadequate negative-swing protection.
What is the recommended PCB pad layout for thermal reliability?
ST specifies a minimum copper surface area of 4.0 cm² per lead (SCU = 4.0 cm²) on FR4 with 35 μm copper thickness, per Figure 10 and Table 5. This layout achieves Rth(j-a) = 90 °C/W and ensures safe operation at 150 °C junction temperature under sustained 500 A pulses, as validated in thermal characterization curves.
Does STIEC45-33AS meet RoHS2 and REACH requirements?
Yes - the device is RoHS2 compliant (2011/65/EU) and REACH SVHC-free, as confirmed in Section 2 ("Package information") and the ECOPACK® environmental documentation referenced in the datasheet. The molding compound also meets UL 94 V0 flammability standards and MIL-STD-750 solderability requirements.
STIEC45-33AS Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- STIEC, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 59V
- 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
STIEC45-33AS FAQ
1.How can I place an order for STIEC45-33AS through Aetrix?
Please submit a Request for Quotation (RFQ) for STIEC45-33AS 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 STIEC45-33AS reliable?
The price and inventory of STIEC45-33AS are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STIEC45-33AS is usually 5 days.
3.What payment methods are accepted for STIEC45-33AS?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STIEC45-33AS transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STIEC45-33AS?
STIEC45-33AS orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STIEC45-33AS 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 STIEC45-33AS?
For technical support, including STIEC45-33AS datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STIEC45-33AS requirements.
6.How does Aetrix verify that STIEC45-33AS is sourced from the original manufacturer or authorized distributors?
All STIEC45-33AS 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 STIEC45-33AS meets industry standards.
7.What is the process for return or replacement of STIEC45-33AS?
All STIEC45-33AS units undergo pre-shipment inspection (PSI). If there is an issue with STIEC45-33AS, 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 STIEC45-33AS part is unused and in its original packaging.
Return procedure for STIEC45-33AS:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STIEC45-33AS Tags
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