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Taiwan Semiconductor Corporation SMF45AH
- Part No.:
- SMF45AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF45AH.pdf
- Description:
- TVS DIODE 45VWM 72.7VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:4,302
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Product details
Overview
SMF45AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode in SOD-123W package, rated for 45 V working stand-off voltage, 50.0–55.3 V breakdown voltage at 1 mA, 72.7 V clamping voltage at 2.8 A peak pulse current, and 200 W peak pulse power (10/1000 µs). It protects automotive-grade electronics against ISO 7637-2 pulses and ESD transients.
For engineers reviewing the SMF45AH datasheet, SMF45AH pinout, SMF45AH application, or SMF45AH equivalent, key selection criteria include clamping performance under 10/1000 µs surge, AEC-Q101 qualification, low leakage (<1 µA above 10 V), moisture sensitivity level 1 compliance, and SOD-123W thermal performance (RθJL = 33 °C/W).
Technical Context
The SMF45AH operates as a unidirectional avalanche diode with glass-passivated junction, designed to clamp fast-rising transients before they damage downstream ICs. Its 45 V VWM enables use in 36 V automotive supply rails, while its 72.7 V VC at 2.8 A ensures safe voltage limiting during ISO 7637-2 Pulse 1 (inductive load dump) and Pulse 2b (battery disconnect).
Thermally, it delivers RθJL = 33 °C/W and RθJA = 100 °C/W on a 5 mm × 5 mm Cu pad PCB, supporting continuous operation up to TJ = 175 °C. The device meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 45 V - Maximum continuous reverse operating voltage before clamping begins; matches 36 V nominal automotive systems with margin. |
| VBR @ IT = 1 mA | 50.0–55.3 V - Breakdown threshold range; defines onset of avalanche conduction under standardized test current. |
| VC @ IPPM = 2.8 A | 72.7 V - Clamped voltage during 10/1000 µs surge; determines maximum stress seen by protected IC inputs. |
| PPPM | 200 W - Peak pulse power handling (10/1000 µs); supports high-energy transients per ISO 7637-2. |
| IR @ VWM | <1 µA - Reverse leakage at 45 V; minimizes standby power loss and avoids false triggering. |
| TJ max | 175 °C - Maximum junction temperature; enables operation in under-hood automotive environments. |
| RθJL | 33 °C/W - Junction-to-lead thermal resistance; critical for estimating temperature rise under pulsed conditions. |
Pinout & Package
Package: SOD-123W - Surface-mount plastic package with matte tin-plated leads, polarity indicated by cathode band, weight ≈ 0.016 g, UL 94V-0 rated molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., ground or return path) in unidirectional TVS configuration. |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., CAN_H, LIN, sensor supply); conducts during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control, body electronics, and ADAS subsystems. |
| Glass-passivated junction | Enhances long-term reliability and stability of breakdown voltage under thermal cycling and humidity stress. |
| ISO 7637-2 compliance | Withstands Pulse 1 (inductive switch-off), Pulse 2a/2b (battery interruption), and Pulse 3a/3b (capacitive coupling) without degradation. |
| Moisture sensitivity level 1 | Enables standard SMT assembly without baking; eliminates pre-reflow moisture mitigation steps. |
| Low clamping ratio (VC/VBR ≈ 1.35) | Ensures tight voltage limiting relative to breakdown, reducing risk of overstress on protected ICs. |
Applications
| Automotive Power Line Protection | CAN Bus Transient Suppression |
|---|---|
Use Scenario: Protecting 12 V/24 V/36 V power distribution networks in vehicle ECUs from load dump and alternator transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between supply rail and ground to clamp surges before reaching PMICs or microcontrollers. Use Value: Withstands 200 W 10/1000 µs pulses and maintains <1 µA leakage at 45 V, preserving system efficiency and reliability. | Use Scenario: Safeguarding high-speed CAN FD transceivers (e.g., TCAN1042, SN65HVD256) against ESD and coupled noise. IC Role / Device Role / Timing Role: Bidirectionally unclamped (via external bias) or used as unidirectional clamp on CAN_H/CAN_L lines with proper grounding strategy. Use Value: 72.7 V clamping voltage prevents transceiver input damage while maintaining signal integrity up to 5 Mbps. |
| LED Lighting Driver Protection | Industrial Sensor Interface Protection |
Use Scenario: Shielding constant-current LED drivers in headlamps and interior lighting from switching spikes and ESD. IC Role / Device Role / Timing Role: TVS connected across driver output or input to absorb inductive kickback from MOSFET switches. Use Value: 50–55.3 V breakdown aligns with 48 V LED string supplies; 2.8 A IPPM handles typical flyback energy. | Use Scenario: Securing analog sensor outputs (e.g., pressure, temperature, position) in factory automation against cable discharge events. IC Role / Device Role / Timing Role: Placed at connector interface to shunt fast transients before reaching ADC front-end or op-amp buffers. Use Value: Sub-1 µA leakage avoids DC offset errors; 33 °C/W RθJL allows localized heat dissipation without thermal runaway. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ45A | Same VWM (45 V), but higher VC (73.0 V), lower PPPM (400 W), SMA package (larger footprint, higher RθJA). | Less suitable for space-constrained automotive modules; requires larger PCB area and exhibits higher thermal resistance (RθJA ≈ 150 °C/W). | Select SMAJ45A only if higher pulse power margin is needed and board space permits larger SMD package. |
| TPSMA6L45A | VWM = 45 V, VC = 72.0 V, PPPM = 600 W, same SOD-123W package, but not AEC-Q101 qualified. | Lacks automotive qualification; limited to industrial or consumer applications where AEC-Q101 is not mandated. | Choose TPSMA6L45A for cost-sensitive non-automotive designs requiring higher surge rating and identical footprint. |
Compared with SMAJ45A and TPSMA6L45A, the SMF45AH offers optimal balance of AEC-Q101 compliance, compact SOD-123W footprint, and verified ISO 7637-2 immunity-making it the preferred choice for automotive ECU and ADAS module protection where qualification and layout density are critical.
Availability
SMF45AH is available at Aetrix Electronics and suitable for automotive power line protection, CAN bus transient suppression, LED lighting driver protection, and industrial sensor interface protection requiring stable component supply and full traceability.
Supply support for SMF45AH 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-Q101 validation capability.
The SMF45AH belongs to TSC's SMF-AH series of automotive-grade TVS diodes, engineered specifically for robust transient immunity in harsh automotive electrical environments-including engine bays, battery management, and communication bus interfaces.
FAQ
What is the clamping voltage of SMF45AH at its rated peak pulse current?
The SMF45AH has a maximum clamping voltage (VC) of 72.7 V when subjected to its specified peak pulse current of 2.8 A using a 10/1000 µs waveform. This value is measured per JEDEC standards and ensures predictable voltage limiting during surge events. The clamping performance is validated across temperature and process variations, and appears consistently in TSC's official datasheet revision A2103. SMF45AH's low clamping ratio supports reliable protection of 48 V-rated ICs.
Is SMF45AH qualified for automotive applications?
Yes, SMF45AH is AEC-Q101 qualified, confirming its suitability for automotive electronic systems. This qualification covers stress tests including high-temperature operating life, temperature cycling, and mechanical shock-all performed on the SOD-123W packaged device. The qualification applies directly to the SMF45AH part number, not just the family. SMF45AH is widely deployed in automotive ECUs, body control modules, and lighting systems where reliability under vibration and thermal extremes is mandatory.
What is the maximum steady-state power dissipation for SMF45AH?
The SMF45AH has a steady-state power dissipation (Ptot) of 1 W at lead temperature (TL) = 25 °C, measured on a standard 5 mm × 5 mm copper pad PCB. This rating assumes proper thermal land design and limits continuous DC power handling-not surge capability. For pulsed operation, the 200 W peak pulse power (10/1000 µs) dominates design considerations. SMF45AH's RθJL = 33 °C/W enables accurate junction temperature estimation under real-world mounting conditions.
Does SMF45AH meet ISO 7637-2 immunity requirements?
Yes, SMF45AH is explicitly rated to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b test waveforms. Its 200 W peak pulse power rating at 10/1000 µs, combined with sub-1 µA leakage and low clamping voltage, ensures compliance across all five pulse types. Test data is documented in TSC's application notes and validated in third-party lab reports referenced in the SMF-AH series datasheet. SMF45AH is routinely selected for power line protection in modules requiring full ISO 7637-2 certification.
What marking code identifies SMF45AH on the device body?
The SMF45AH is marked with the code "2W045" on its SOD-123W package body, followed by date and factory codes. This marking is confirmed in the Electrical Specifications table of TSC's datasheet revision A2103 and matches the ordering information section. The "2W045" identifier distinguishes it from adjacent variants (e.g., SMF43AH = "2W043", SMF48AH = "2W048") and enables visual verification during incoming inspection. SMF45AH's marking remains consistent across production lots and wafer fab sources.
SMF45AH 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):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 2.8A
- Power - Peak Pulse:
- 200W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOD-123W
SMF45AH FAQ
1.How can I place an order for SMF45AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF45AH 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 SMF45AH reliable?
The price and inventory of SMF45AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF45AH is usually 5 days.
3.What payment methods are accepted for SMF45AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF45AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF45AH?
SMF45AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF45AH 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 SMF45AH?
For technical support, including SMF45AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF45AH requirements.
6.How does Aetrix verify that SMF45AH is sourced from the original manufacturer or authorized distributors?
All SMF45AH 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 SMF45AH meets industry standards.
7.What is the process for return or replacement of SMF45AH?
All SMF45AH units undergo pre-shipment inspection (PSI). If there is an issue with SMF45AH, 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 SMF45AH part is unused and in its original packaging.
Return procedure for SMF45AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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