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STMicroelectronics SMA4F170A
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- Part No.:
- SMA4F170A
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-221AC, SMA Flat Leads
- Datasheet:
-
SMA4F170A.pdf
- Description:
- TVS DIODE 170VWM 275VC SMAFLAT
- Quantity:
- Payment:
- Shipping:
Inventory:17,879
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Product details
Overview
SMA4F170A from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode designed for high-reliability surge protection in power and signal lines. It features a 170 V stand-off voltage (VRM), 275 V clamping voltage (VCL) at 1 A, 400 W peak pulse power (10/1000 µs), and operates up to 175 °C junction temperature-ideal for industrial power supplies and telecom interface protection.
For engineers reviewing the SMA4F170A datasheet, SMA4F170A pinout, SMA4F170A application, or SMA4F170A 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 SMA4F170A employs planar silicon avalanche technology to deliver precise breakdown behavior with tight VBR tolerance (190–210 V at 1 mA) and low dynamic resistance (22.2 Ω). Its unidirectional configuration enables asymmetric surge handling on DC-biased lines without reverse conduction during normal operation.
It meets IEC 61000-4-2 ESD immunity requirements with verified clamping response under 150 pF / 330 Ω discharge networks, and supports high-temperature reliability via MSL Level 1 moisture sensitivity and 260 °C soldering tolerance-critical for reflow-compatible industrial PCB assembly.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 170 V - Maximum continuous reverse operating voltage before leakage exceeds 0.2 µA |
| Breakdown Voltage (VBR) | 190–210 V @ 1 mA - Ensures reliable triggering above system nominal voltage with margin |
| Clamping Voltage (VCL) | 275 V @ 1 A (10/1000 µs) - Limits downstream voltage stress during surge events |
| Peak Pulse Power | 400 W (10/1000 µs), 2.5 kW (8/20 µs) - Supports robust surge handling per IEC 61000-4-5 |
| Leakage Current | 0.2 µA @ 25 °C, 1 µA @ 85 °C - Minimizes standby power loss in battery-backed or low-power systems |
| Junction Temperature Range | -55 °C to +175 °C - Enables deployment in under-hood automotive, industrial motor drives, and outdoor telecom equipment |
| ESD Rating | ±25 kV contact / ±30 kV air (IEC 61000-4-2 Level 4) - Exceeds standard immunity requirements for user-accessible ports |
Pinout & Package
The SMA4F170A uses the industry-standard SMA (DO-214AC) flat package: 2.25–2.90 mm width (D), 5.00–5.35 mm length (E), 0.90–1.10 mm height (A), with matte tin-plated leads compliant with J-STD-002 and JEDEC registered outline.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (Marked Band) | Surge current sink | Connected to protected line; conducts transient energy to ground when VREV > VBR |
| Anode | Reference / Ground return | Typically tied to system ground or low-impedance return path for controlled clamping |
Key Features
| Feature | Design Value |
|---|---|
| High-temperature operation | Rated for continuous use up to +175 °C junction temperature-enables placement near heat sources without derating |
| Low-leakage planar construction | 0.2 µA max @ VRM and 25 °C-reduces parasitic loading on high-impedance sensor or reference circuits |
| Stable clamping under thermal stress | VCL drift compensated by αT = 10.8 × 10⁻⁴ /°C-ensures predictable protection across full operating range |
| Robust ESD immunity | Exceeds IEC 61000-4-2 Level 4-validates suitability for USB, RS-485, and Ethernet port protection |
| MSL Level 1 packaging | No floor life limitation-supports unlimited storage and standard SMT reflow without baking |
Applications
| Industrial Power Supply Input Protection | Telecom Line Interface Protection |
|---|---|
Use Scenario: Protecting AC/DC converter inputs against lightning-induced surges and load dump transients in DIN-rail mounted PSUs. IC Role / Device Role / Timing Role: Unidirectional TVS diode placed between L/N and PE or DC+ and GND to clamp fast-rising overvoltages. Use Value: 275 V clamping at 1 A ensures downstream rectifier and controller ICs remain below absolute maximum ratings during 400 W surge events. | Use Scenario: Shielding RS-485 transceivers and PoE injectors from ESD and induced surges on outdoor data links. IC Role / Device Role / Timing Role: Primary-level surge suppressor on differential bus lines, coordinated with secondary filtering. Use Value: ±30 kV air discharge rating prevents latch-up or damage during field maintenance or connector mating cycles. |
| Automotive Body Control Module (BCM) Inputs | Renewable Energy Inverter DC Link Monitoring |
Use Scenario: Safeguarding microcontroller GPIOs and LIN bus receivers connected to external sensors in engine bay environments. IC Role / Device Role / Timing Role: Localized TVS on each input trace, leveraging high Tj rating to survive under-hood thermal cycling. Use Value: 175 °C max junction temperature allows direct placement near high-power drivers without thermal derating. | Use Scenario: Protecting voltage sense circuitry monitoring high-voltage DC link (e.g., 150–200 V) in solar inverters and battery storage systems. IC Role / Device Role / Timing Role: Stand-off matched to DC link nominal voltage (170 V VRM) to avoid false triggering while enabling fast clamping. Use Value: Tight VBR tolerance (190–210 V) ensures consistent activation threshold across production lots and temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ170A (Bourns) | Same SMA package, 170 V VRM, but lower peak power (400 W vs. SMA4F170A's 400 W); VCL = 279 V @ 1 A | Marginally higher clamping voltage reduces protection margin for 3.3 V or 5 V logic interfaces downstream | Select when footprint compatibility is critical and clamping margin ≥4 V is acceptable |
| 1.5SMC170A (ON Semiconductor) | Higher package thermal mass (SMC/DO-214AB), 170 V VRM, VCL = 275 V @ 1 A, but rated only to 150 °C Tj | Not suitable for under-hood or high-ambient industrial deployments requiring 175 °C operation | Prefer for cost-sensitive consumer applications where ambient temperature stays <85 °C |
Compared with SMAJ170A and 1.5SMC170A, the SMA4F170A delivers identical clamping performance at 1 A but uniquely combines 175 °C operation, MSL Level 1 compliance, and tighter VBR distribution-making it optimal for thermally demanding, high-reliability industrial and automotive designs.
Availability
SMA4F170A is available at Aetrix Electronics and suitable for industrial power supply input protection, telecom line interface hardening, automotive body control module inputs, and renewable energy inverter DC link monitoring requiring stable component supply and long-term lifecycle support.
Supply support for SMA4F170A 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 microcontrollers for industrial, automotive, and consumer markets.
The SMA4F Transil series targets high-reliability transient suppression in thermally constrained environments-designed specifically for applications demanding low leakage, extended temperature operation, and repeatable clamping performance under repeated surge stress.
FAQ
What is the maximum clamping voltage of SMA4F170A under a 10/1000 µs surge?
The maximum clamping voltage (VCL) of SMA4F170A is 275 V at 1 A for a 10/1000 µs waveform, measured at 25 °C ambient. This value increases with junction temperature at a coefficient of 10.8 × 10⁻⁴ /°C, reaching approximately 292 V at 175 °C junction temperature per datasheet calculation.
Is SMA4F170A suitable for bidirectional signal line protection?
No-SMA4F170A is a unidirectional TVS diode, intended for DC-biased or ground-referenced lines. It does not conduct in forward bias beyond ~1.5 V and offers no protection against positive-going transients on AC-coupled or floating lines. For bidirectional protection, a symmetric device like SMA4F170CA must be selected.
Does SMA4F170A require derating at elevated ambient temperatures?
Yes-peak pulse power must be derated above 25 °C ambient. At 100 °C ambient, the 10/1000 µs power rating drops to ~240 W; at 150 °C, it falls to ~120 W. Derating curves are provided in Figure 3 of DS12542, and thermal design must account for PCB copper area and airflow to maintain Tj ≤ 175 °C.
What marking appears on the SMA4F170A package?
The SMA4F170A is marked "4HG" on the cathode band side of the SMA package, per Table 6 in DS12542. This 3-character alphanumeric code is laser-etched or printed and aligns with ST's standardized marking scheme for the SMA4FxxA series.
SMA4F170A 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):
- 170V (Max)
- Voltage - Breakdown (Min):
- 190V
- Voltage - Clamping (Max) @ Ipp:
- 275V
- Current - Peak Pulse (10/1000µs):
- 1.4A
- 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
SMA4F170A FAQ
1.How can I place an order for SMA4F170A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA4F170A 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 SMA4F170A reliable?
The price and inventory of SMA4F170A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA4F170A is usually 5 days.
3.What payment methods are accepted for SMA4F170A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA4F170A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA4F170A?
SMA4F170A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA4F170A 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 SMA4F170A?
For technical support, including SMA4F170A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA4F170A requirements.
6.How does Aetrix verify that SMA4F170A is sourced from the original manufacturer or authorized distributors?
All SMA4F170A 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 SMA4F170A meets industry standards.
7.What is the process for return or replacement of SMA4F170A?
All SMA4F170A units undergo pre-shipment inspection (PSI). If there is an issue with SMA4F170A, 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 SMA4F170A part is unused and in its original packaging.
Return procedure for SMA4F170A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMA4F170A Tags
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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