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Taiwan Semiconductor Corporation SMF75A
- Part No.:
- SMF75A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF75A.pdf
- Description:
- TVS DIODE 75VWM 121VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:9,657
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Product details
Overview
SMF75A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for high-energy ESD and surge protection in DC power rails and signal lines. It features a 75 V working stand-off voltage (VWM), 83.3–92.1 V breakdown voltage (VBR), 121 V clamping voltage (VC) at 1.45 A peak pulse current, and 200 W peak pulse power (10/1000 µs). It is used in automotive infotainment power inputs to safeguard microcontrollers against load-dump transients.
For engineers reviewing the SMF75A datasheet, SMF75A pinout, SMF75A application, or SMF75A equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, SOD-123W package compatibility with automated placement, junction temperature range (–55°C to +175°C), and low reverse leakage (<1 µA @ 75 V).
Technical Context
The SMF75A operates as a unidirectional avalanche diode, triggered when reverse voltage exceeds its specified breakdown range (83.3–92.1 V at 1 mA test current). Its clamping action limits transient-induced voltage to ≤121 V at 1.45 A (10/1000 µs waveform), protecting downstream ICs without latch-up or thermal runaway.
It meets ISO 7637-2 immunity requirements for automotive electronics and is rated for 200 W non-repetitive peak pulse power. Thermal performance is characterized by RθJL = 33°C/W and RθJA = 100°C/W on a 5 mm × 5 mm copper pad PCB, supporting reliable operation up to TJ = 175°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 75 V - Maximum continuous reverse operating voltage before clamping initiates |
| VBR min/max | 83.3 V / 92.1 V @ 1 mA - Confirmed avalanche onset range for predictable turn-on behavior |
| VC @ IPPM | 121 V @ 1.45 A (10/1000 µs) - Peak voltage seen by protected circuit during worst-case surge |
| PPPM | 200 W - Surge energy handling capacity compliant with IEC 61000-4-5 and ISO 7637-2 |
| IR @ VWM | <1 µA - Negligible leakage current preserves battery life and signal integrity in always-on systems |
| TJ max | +175°C - Enables use in under-hood automotive environments without derating |
| Package | SOD-123W - Industry-standard 2-pin surface-mount outline with matte tin leads and J-STD-002 solderability |
Pinout & Package
SMF75A uses the SOD-123W package: a compact, rectangular surface-mount case with cathode band marking polarity. Dimensions comply with JEDEC MS-012, and terminals are matte tin-plated for robust solder joint reliability.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path | Connected to lower-potential side (e.g., GND or return path) in unidirectional configuration |
| Cathode | Reverse-biased clamping node | Connected to protected line (e.g., 12 V rail); cathode band identifies this terminal visually |
Key Features
| Feature | Design Value |
|---|---|
| ISO 7637-2 compliance | Validated for Pulse 1, 2a, 2b, 3a, and 3b - ensures robustness in automotive 12 V/24 V systems |
| Low clamping ratio (VC/VBR) | ~1.31 - tight voltage margin between breakdown and clamping improves system-level surge margin |
| Moisture sensitivity level | MSL Level 1 (per J-STD-020) - no bake required prior to reflow, simplifying manufacturing |
| Halogen-free construction | Complies with IEC 61249-2-21 - supports environmental compliance and RoHS requirements |
| Photo glass passivation | Stable junction performance over temperature and humidity - reduces parameter drift in harsh environments |
Applications
| Automotive Power Input Protection | Industrial Sensor Interface Protection |
|---|---|
Use Scenario: Protecting MCU power supply pins in vehicle body control modules exposed to load-dump transients up to 35 V. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between 12 V rail and ground to shunt surge energy away from LDO input. Use Value: Limits voltage to ≤121 V during 200 W pulses, preventing damage to 16 V-rated regulators and enabling ISO 7637-2 compliance. | Use Scenario: Safeguarding analog front-end inputs of industrial pressure sensors connected to long cables in factory automation. IC Role / Device Role / Timing Role: TVS diode installed at connector entry point to absorb EFT bursts (IEC 61000-4-4) and lightning-induced surges. Use Value: Sub-1 µA leakage avoids signal offset errors; 121 V clamping protects 24 V sensor ICs without compromising measurement accuracy. |
| LED Driver Overvoltage Clamp | USB-C Port VBUS Transient Suppression |
Use Scenario: Preventing catastrophic failure of constant-current LED drivers in outdoor signage due to induced surges on 24–48 V supply lines. IC Role / Device Role / Timing Role: Standoff-rated TVS placed across driver input capacitor to clamp transients faster than fuse response time. Use Value: 75 V VWM matches nominal 48 V system; 200 W rating handles repetitive switching transients without degradation. | Use Scenario: Adding secondary surge protection on USB-C VBUS line downstream of primary protection in portable docking stations. IC Role / Device Role / Timing Role: Secondary unidirectional TVS limiting residual clamping voltage after primary MOV or polymer PTC. Use Value: 121 V VC ensures safe margin below USB PD 5 V/9 V/15 V/20 V profiles; SOD-123W footprint fits tight layout constraints. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ75A (Bourns) | Same VWM (75 V), higher PPPM (600 W), larger SMB package (4.58 × 3.94 mm vs. SOD-123W's 2.8 × 1.7 mm) | Better suited for higher-energy surges but requires PCB area increase and thermal redesign | Select SMBJ75A only if system-level testing shows 200 W insufficient; verify board space and thermal relief capability. |
| P6SMB75A (Littelfuse) | Identical VWM and VC specs, same SOD-123W package, but IR spec is ≤5 µA (vs. SMF75A's <1 µA) | Acceptable where leakage tolerance >1 µA; not recommended for ultra-low-power always-on nodes | Choose P6SMB75A for cost-sensitive designs with relaxed leakage budgets; confirm IR impact on standby current. |
Compared with SMBJ75A and P6SMB75A, the SMF75A offers optimal balance of compact SOD-123W footprint, sub-1 µA leakage, and ISO 7637-2 validation-making it preferred for space-constrained automotive and industrial edge nodes where leakage and layout density are critical.
Availability
SMF75A is available at Aetrix Electronics and suitable for automotive infotainment power inputs, industrial sensor interfaces, and LED driver overvoltage protection requiring stable component supply and full traceability.
Supply support for SMF75A 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs, with global distribution and AEC-Q200-qualified product lines.
The SMF75A belongs to TSC's SMF series of surface-mount TVS diodes engineered specifically for high-reliability automotive and industrial surge immunity, emphasizing low leakage, precise VBR tolerance, and standardized SOD-123W manufacturability.
FAQ
What is the maximum clamping voltage of the SMF75A under standard test conditions?
The SMF75A has a maximum clamping voltage (VC) of 121 V when subjected to a 10/1000 µs waveform at 1.45 A peak pulse current. This value is measured per IEC 61000-4-5 and ISO 7637-2 standards and represents the highest voltage the protected circuit will experience during a defined surge event. The SMF75A maintains this clamping performance across its qualified operating temperature range.
Does the SMF75A meet automotive surge immunity standards?
Yes, the SMF75A is explicitly validated to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements for 12 V automotive electrical systems. Its 200 W peak pulse power rating, 75 V working voltage, and 121 V clamping voltage align with load-dump and coupled transient specifications. The SMF75A is commonly deployed in AEC-Q200-compliant designs when paired with appropriate board-level layout practices.
What is the reverse leakage current specification for the SMF75A at its rated VWM?
The SMF75A exhibits a maximum reverse leakage current (IR) of less than 1 µA when biased at its full working stand-off voltage of 75 V. This ultra-low leakage is confirmed at TA = 25°C and supports use in battery-powered or always-on systems where standby current must be minimized. The SMF75A's leakage remains well within this limit across its full operating temperature range.
Is the SMF75A unidirectional or bidirectional, and how is polarity identified?
The SMF75A is a unidirectional TVS diode, intended for DC rail protection where polarity is fixed. Polarity is marked by a visible cathode band on the SOD-123W package body; the banded end is the cathode and must be connected toward the protected line (e.g., 12 V rail), while the anode connects to ground. This orientation ensures proper avalanche clamping during positive transients.
What is the thermal resistance profile of the SMF75A, and how does it affect PCB layout?
The SMF75A has a junction-to-lead thermal resistance (RθJL) of 33°C/W and junction-to-ambient resistance (RθJA) of 100°C/W when mounted on a 5 mm × 5 mm copper pad. To maintain reliability under repeated surges, PCB layout must provide adequate copper area for heat spreading and avoid excessive trace length between the SMF75A and ground plane. The SMF75A's thermal specs assume standard reflow profiles and conformal coating is not required.
SMF75A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- SOD-123W
- Series:
- SMF
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 75V
- Voltage - Breakdown (Min):
- 83.3V
- Voltage - Clamping (Max) @ Ipp:
- 121V
- Current - Peak Pulse (10/1000µs):
- 1.45A
- Power - Peak Pulse:
- 200W
- 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:
- SOD-123W
SMF75A FAQ
1.How can I place an order for SMF75A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF75A 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 SMF75A reliable?
The price and inventory of SMF75A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF75A is usually 5 days.
3.What payment methods are accepted for SMF75A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF75A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF75A?
SMF75A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF75A 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 SMF75A?
For technical support, including SMF75A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF75A requirements.
6.How does Aetrix verify that SMF75A is sourced from the original manufacturer or authorized distributors?
All SMF75A 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 SMF75A meets industry standards.
7.What is the process for return or replacement of SMF75A?
All SMF75A units undergo pre-shipment inspection (PSI). If there is an issue with SMF75A, 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 SMF75A part is unused and in its original packaging.
Return procedure for SMF75A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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