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STMicroelectronics SMA4F30A
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- Part No.:
- SMA4F30A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AC, SMA Flat Leads
- Datasheet:
-
SMA4F30A.pdf
- Description:
- TVS DIODE 30VWM 64.3VC SMAFLAT
- Quantity:
- Payment:
- Shipping:
Inventory:9,876
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Product details
Overview
SMA4F30A from STMicroelectronics is a unidirectional 400 W transient voltage suppression (TVS) diode designed for primary-level surge protection in DC power rails and signal lines. It features a 30 V stand-off voltage (VRM), 33.2–36.8 V breakdown voltage (VBR) at 1 mA, 48.4 V clamping voltage (VCL) at 8.3 A (10/1000 µs), and operates up to 175 °C junction temperature - ideal for automotive body electronics and industrial power supply input stages.
For engineers reviewing the SMA4F30A datasheet, SMA4F30A pinout, SMA4F30A application, or SMA4F30A equivalent, key selection criteria include clamping performance under IEC 61000-4-2 Level 4 (±25 kV contact / ±30 kV air), low leakage (<0.2 µA @ 25 °C), and thermal stability across -55 °C to +175 °C operation.
Technical Context
The SMA4F30A employs planar silicon avalanche technology to deliver precise voltage clamping during fast transients. Its unidirectional configuration enables integration on positive-rail-only paths without reverse-bias concerns, and its low dynamic resistance (0.761 Ω) ensures minimal voltage overshoot under high-current surges.
Designed for compliance with IEC 61000-4-2 and UL94 V0, it sustains 400 W peak pulse power (10/1000 µs) at 25 °C and retains 200 W capability at Tj = 175 °C. The device's αT voltage temperature coefficient (9.9 × 10⁻⁴ /°C) allows accurate VBR and VCL derating over temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 30 V - maximum continuous reverse operating voltage before leakage exceeds 0.2 µA |
| Breakdown Voltage (VBR) | 33.2–36.8 V at 1 mA - defines onset of avalanche conduction; tight tolerance supports predictable protection threshold |
| Clamping Voltage (VCL) | 48.4 V at 8.3 A (10/1000 µs) - limits downstream voltage stress during surge events |
| Peak Pulse Power (PPP) | 400 W (10/1000 µs) - sustains 8.3 A surge for 1 ms without failure at 25 °C ambient |
| Junction Temperature Range | -55 °C to +175 °C - enables deployment in under-hood automotive and high-temp industrial environments |
| Leakage Current (IRM) | 0.2 µA max @ VRM and 25 °C - minimizes standby power loss in battery-powered systems |
| Dynamic Resistance (RD) | 0.761 Ω - determines VCL rise per unit current; critical for precision clamping design |
Pinout & Package
The SMA4F30A is housed in an industry-standard SMA (DO-214AC) flat package with matte tin-plated leads, compliant with IPC7531 footprint and JEDEC MO-136AA outline. Dimensions: 4.60 mm × 2.90 mm × 2.20 mm (L × W × H), weight 39 mg.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked band) | Surge current sink terminal | Connected to protected line; conducts avalanche current to ground during overvoltage |
| Anode | Reference/return terminal | Tied to system ground or lower-potential rail; completes conduction path during transient |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 Level 4 compliance | Withstands ±25 kV contact and ±30 kV air discharge - eliminates need for external ESD staging in Class B/C designs |
| High-temperature reliability | Rated for 175 °C junction operation with 200 W pulse power retention - supports compact heatsink-free placement near hot components |
| Low dynamic resistance | 0.761 Ω enables <1 V/A clamping slope - reduces voltage overshoot on 12 V/24 V rails during 5–10 A surges |
| MSL Level 1 moisture sensitivity | Unlimited floor life at ≤30 °C/60% RH - eliminates bake requirements prior to reflow assembly |
| UL94 V0 flammability rating | Self-extinguishing epoxy molding compound - satisfies safety requirements for enclosed industrial enclosures |
Applications
| Automotive Body Control Module (BCM) | Industrial PLC Digital Input Card |
|---|---|
Use Scenario: Protecting 12 V CAN/LIN bus power inputs against load dump and ISO 7637-2 pulses. IC Role / Device Role: Primary TVS clamp on main VBAT rail upstream of DC-DC converters and interface ICs. Use Value: Clamps to 48.4 V at 8.3 A, preventing damage to 36 V-rated regulators and transceivers during 100 V/50 ms transients. |
Use Scenario: Safeguarding 24 V digital input channels from field-wiring induced surges and inductive kickback. IC Role / Device Role: Front-end transient suppressor before optocoupler or Schmitt-trigger input stage. Use Value: Sub-µA leakage preserves input hysteresis thresholds; 175 °C rating allows mounting directly on DIN-rail mounted PCBs. |
| Telecom Power Supply Input | Smart Meter AC/DC Auxiliary Rail |
Use Scenario: Secondary surge protection on +48 V telecom rectifier outputs feeding PoE PSE controllers. IC Role / Device Role: Fast-response clamp between bulk capacitor and DC-DC controller IC. Use Value: 0.761 Ω RD limits clamping rise to <6 V above VBR under 10 A surge - maintains regulation margin for 52 V-rated controllers. |
Use Scenario: Protecting 5 V auxiliary rail derived from mains-connected SMPS against lightning-induced surges on neutral/line coupling. IC Role / Device Role: Final-stage TVS after primary MOV and gas discharge tube filtering. Use Value: 48.4 V clamping prevents latch-up in microcontroller LDOs rated for 6 V absolute max input. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ30A (onsemi) | Same SMA package; 400 W PPP; VBR = 33.3–36.8 V; VCL = 48.4 V @ 8.3 A; higher IRM (1 µA @ 25 °C) | Higher leakage may affect ultra-low-power metering circuits; identical clamping performance | Select when sourcing diversification is required and 1 µA leakage is acceptable in the system |
| SMBJ30A (Littelfuse) | SMB package (larger footprint); 600 W PPP; VBR = 33.3–36.8 V; VCL = 48.4 V @ 12.3 A; same 175 °C rating | Requires PCB redesign; offers higher surge margin but sacrifices board space efficiency | Choose for legacy SMB layouts or where >600 W single-pulse robustness is mandated by end-equipment standards |
Compared with SMAJ30A and SMBJ30A, the SMA4F30A provides optimal balance of low leakage (0.2 µA), compact SMA footprint, and verified 400 W IEC 61000-4-2 compliance - making it preferred for space-constrained, high-reliability automotive and industrial control designs.
Availability
SMA4F30A is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC input protection, telecom power supply inputs, and smart meter auxiliary rail protection requiring stable component supply across extended temperature and surge stress conditions.
Supply support for SMA4F30A 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, sensing, and control solutions for automotive, industrial, and consumer markets.
The SMA4F Transil series targets high-reliability transient suppression in thermally demanding environments, emphasizing low leakage, wide temperature operation, and IEC/UL-certified surge immunity for mission-critical power and signal interfaces.
FAQ
What is the maximum clamping voltage of SMA4F30A under IEC 61000-4-2 testing?
The SMA4F30A clamps to ≤48.4 V at 8.3 A for 10/1000 µs waveform and ≤64.3 V at 36 A for 8/20 µs waveform, both measured at Tj = 25 °C. These values are guaranteed per Table 2 in DS12542 Rev 1 and validated per IEC 61000-4-2 test conditions with 150 pF/330 Ω network.
Can SMA4F30A be used in bidirectional signal line protection?
No - SMA4F30A is unidirectional only, with cathode marking indicating polarity-sensitive installation. For bidirectional protection (e.g., RS-485, USB D+/D−), ST recommends the SMA4F30AY variant or discrete back-to-back configurations using two unidirectional devices.
Does SMA4F30A require derating at elevated ambient temperatures?
Yes - peak pulse power must be derated linearly from 400 W at 25 °C to 200 W at 175 °C, per Figure 3 in DS12542. Clamping voltage also increases with junction temperature using αT = 9.9 × 10⁻⁴ /°C, per footnote 1 in Table 2.
Is the SMA4F30A RoHS and REACH compliant?
Yes - SMA4F30A is manufactured in ST's ECOPACK®-compliant facilities and meets RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006. Full material declarations and compliance certificates are available via ST's Quality Portal upon registration.
SMA4F30A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-221AC, SMA Flat Leads
- Series:
- SMA4F, TRANSIL™
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 30V
- Voltage - Breakdown (Min):
- 33.2V
- Voltage - Clamping (Max) @ Ipp:
- 64.3V
- Current - Peak Pulse (10/1000µs):
- 8.3A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMAflat
SMA4F30A FAQ
1.How can I place an order for SMA4F30A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA4F30A 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 SMA4F30A reliable?
The price and inventory of SMA4F30A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA4F30A is usually 5 days.
3.What payment methods are accepted for SMA4F30A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA4F30A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA4F30A?
SMA4F30A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA4F30A 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 SMA4F30A?
For technical support, including SMA4F30A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA4F30A requirements.
6.How does Aetrix verify that SMA4F30A is sourced from the original manufacturer or authorized distributors?
All SMA4F30A 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 SMA4F30A meets industry standards.
7.What is the process for return or replacement of SMA4F30A?
All SMA4F30A units undergo pre-shipment inspection (PSI). If there is an issue with SMA4F30A, 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 SMA4F30A part is unused and in its original packaging.
Return procedure for SMA4F30A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMA4F30A Tags
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