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STMicroelectronics SMC30J28A
- Part No.:
- SMC30J28A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SMC30J28A.pdf
- Description:
- TVS DIODE 28VWM 45.4VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:2,621
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Product details
Overview
SMC30J28A from STMicroelectronics is a unidirectional 3000 W transient voltage suppression diode designed for primary-level ESD and surge protection in DC power rails and signal lines. It features a 28 V stand-off voltage (VRM), 34.3 V maximum clamping voltage at 168 A (8/20 µs), and 0.2 µA leakage current at 25 °C, operating up to 175 °C junction temperature - deployed in industrial power supplies and automotive body control modules.
For engineers reviewing the SMC30J28A datasheet, SMC30J28A pinout, SMC30J28A application, or SMC30J28A equivalent, key selection criteria include clamping performance under IEC 61000-4-2 (±30 kV contact/air) and IEC 61000-4-4 level 4 (4 kV), low dynamic resistance (41.4 mΩ), and SMC package compatibility with IPC7531 footprints.
Technical Context
The SMC30J28A employs planar junction silicon avalanche technology optimized for fast response (<1 ns) to electrostatic discharge and repetitive surges. Its unidirectional configuration provides forward conduction path during overvoltage events while maintaining high impedance in normal operation.
It delivers 3000 W peak pulse power (10/1000 µs) and up to 40 kW (8/20 µs), with thermal derating down to ~1500 W at 125 °C junction temperature per Figure 3. The device meets MIL-STD-883 Method 3015 and IEC 61000-4-2/4-4 compliance without external circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 28 V - Maximum continuous reverse working voltage before breakdown; defines safe operating margin for 24 V nominal DC systems. |
| Breakdown Voltage (VBR min) | 31.1 V at 1 mA - Guaranteed avalanche initiation threshold; ensures reliable triggering above system transients. |
| Clamping Voltage (VCL max) | 45.4 V at 168 A (8/20 µs) - Peak voltage seen by protected circuit during worst-case surge; limits stress on downstream ICs. |
| Peak Pulse Power (PPP) | 3000 W (10/1000 µs) - Sustained energy-handling capability for lightning-induced surges in industrial environments. |
| Leakage Current (IRM) | 0.2 µA at 25 °C - Negligible standby power loss; critical for battery-backed or low-power sensor nodes. |
| Operating Junction Temp | –55 °C to +175 °C - Enables deployment in under-hood automotive or high-temperature industrial enclosures. |
| Dynamic Resistance (RD) | 41.4 mΩ - Low impedance during clamping reduces voltage overshoot and improves protection fidelity. |
Pinout & Package
SMC30J28A uses the JEDEC-registered SMC (DO-214AB) surface-mount package: 7.75–8.15 mm length × 5.55–6.25 mm width × 2.45 mm height, matte tin-plated leads, MSL Level 1, compatible with standard reflow profiles (peak 240–245 °C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Marked Band) | Surge Return Path | Connected to ground or low-impedance return; conducts avalanche current during positive transients on anode side. |
| Anode | Protected Line Input | Connected to line being protected (e.g., 24 V rail); blocks reverse current until VBR exceeded. |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 ESD Robustness | ±30 kV air/contact discharge - Eliminates need for secondary ESD stages in USB, CAN, or sensor interfaces. |
| Low Clamping Ratio (VCL/VBR) | 1.46 (45.4 V / 31.1 V) - Minimizes overvoltage exposure to protected ICs versus competing TVS devices. |
| High-Temperature Stability | Rated to 175 °C Tj - Maintains clamping performance in engine control units or motor drive inverters. |
| JEDEC-Compliant Footprint | IPC7531-recommended pad layout - Ensures manufacturability and thermal reliability on FR4 PCBs with 70 µm copper. |
| Whisker-Resistant Finish | JESD201 Class 2 tin plating - Prevents tin whisker growth in long-life industrial deployments (>15 years). |
Applications
| Industrial Power Supply 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 clamp on main DC input rail; responds within <1 ns to suppress transients before they reach DC-DC converters. Use Value: Limits clamped voltage to 45.4 V, protecting 36 V-rated input capacitors and enabling single-stage protection architecture. |
Use Scenario: LIN bus transceiver power rail in door module subjected to ESD events during assembly and field use. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VBAT and GND near transceiver IC; absorbs ±30 kV contact discharges per IEC 61000-4-2. Use Value: 0.2 µA leakage avoids battery drain in sleep mode; 175 °C rating supports under-dash mounting near HVAC ducts. |
| Telecom Remote Radio Unit (RRU) | Smart Energy Meter Interface |
|
Use Scenario: 48 V DC power feed to outdoor base station radio unit experiencing lightning-induced surges on PoE-like distribution lines. IC Role / Device Role / Timing Role: First-line defense against 8/20 µs surges up to 168 A; coordinates with upstream fuses and downstream MOVs. Use Value: 40 kW surge handling (8/20 µs) enables robust front-end protection without oversized components or derating penalties. |
Use Scenario: RS-485 communication port on utility meter exposed to induced surges from nearby switching loads and ESD during field servicing. IC Role / Device Role / Timing Role: Bidirectional-capable series (SMC30J28CA exists), but SMC30J28A used on VCC rail; clamps transients before reaching isolated RS-485 transceiver. Use Value: 41.4 mΩ dynamic resistance ensures minimal voltage overshoot during fast transients, preserving signal integrity on 100 kbps bus. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ28A (ON Semiconductor) | Same VRM (28 V), lower PPP (600 W), higher VCL (48.4 V @ 123 A), SMB package (smaller footprint, lower thermal mass) | Limited to lower-energy surges; unsuitable for IEC 61000-4-4 level 4 or 10/1000 µs lightning events | Select only when space-constrained and surge threat is limited to ESD-only environments. |
| 1.5KE28A (Littelfuse) | Same VRM (28 V), axial leaded DO-201 package, 1500 W PPP, higher leakage (5 µA), no MSL rating | Not suitable for automated SMT assembly; requires manual soldering and lacks reflow compatibility | Choose only for prototyping or legacy through-hole designs where SMT is unavailable. |
Compared with SMBJ28A and 1.5KE28A, SMC30J28A uniquely combines 3000 W surge rating, SMT-ready SMC packaging, MSL Level 1 compliance, and sub-µA leakage - making it the only option qualified for high-reliability, high-volume industrial and automotive production.
Availability
SMC30J28A is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, telecom remote radio units, and smart energy meter interfaces requiring stable component supply across multi-year production cycles.
Supply support for SMC30J28A 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 automotive, industrial, and power discrete technologies with vertical manufacturing capabilities.
The SMC30J TVS series targets high-reliability DC rail protection in harsh environments, emphasizing thermal stability, low leakage, and full IEC/MIL standard compliance for mission-critical infrastructure.
FAQ
What is the maximum clamping voltage of SMC30J28A under a 168 A 8/20 µs surge?
The maximum clamping voltage is 45.4 V, measured at 168 A peak pulse current with 8/20 µs waveform per Table 2 of DS8598 Rev 8. This value is guaranteed across –55 °C to +175 °C junction temperature range using the αT coefficient (9.8 × 10⁻⁴/°C) for thermal adjustment.
Can SMC30J28A be used in bidirectional signal line protection?
No - SMC30J28A is unidirectional and conducts only in reverse breakdown. For bidirectional protection (e.g., RS-485, USB D+/D−), the pin-compatible SMC30J28CA variant must be used, which provides symmetrical clamping for both polarities.
Does SMC30J28A meet RoHS and REACH requirements?
Yes - it is manufactured in ST's ECOPACK2-compliant facilities, meeting RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, with lead-free matte tin plating and halogen-free molding compound per DS8598 Section 2.
What is the recommended PCB footprint for optimal thermal performance?
The IPC7531-recommended footprint specifies 8.19 mm × 5.11 mm pads with 3.14 mm spacing, using 70 µm copper thickness on FR4. Thermal resistance drops from 100 °C/W (minimal copper) to 40 °C/W with 4 cm² total copper area per lead, per Figure 12.
SMC30J28A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- SMC30J
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 28V
- Voltage - Breakdown (Min):
- 31.1V
- Voltage - Clamping (Max) @ Ipp:
- 45.4V
- Current - Peak Pulse (10/1000µs):
- 66A
- Power - Peak Pulse:
- 3000W (3kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC (DO-214AB)
SMC30J28A FAQ
1.How can I place an order for SMC30J28A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMC30J28A 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 SMC30J28A reliable?
The price and inventory of SMC30J28A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMC30J28A is usually 5 days.
3.What payment methods are accepted for SMC30J28A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMC30J28A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMC30J28A?
SMC30J28A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMC30J28A 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 SMC30J28A?
For technical support, including SMC30J28A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMC30J28A requirements.
6.How does Aetrix verify that SMC30J28A is sourced from the original manufacturer or authorized distributors?
All SMC30J28A 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 SMC30J28A meets industry standards.
7.What is the process for return or replacement of SMC30J28A?
All SMC30J28A units undergo pre-shipment inspection (PSI). If there is an issue with SMC30J28A, 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 SMC30J28A part is unused and in its original packaging.
Return procedure for SMC30J28A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMC30J28A Tags
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