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Taiwan Semiconductor Corporation SMF33AH
- Part No.:
- SMF33AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF33AH.pdf
- Description:
- TVS DIODE 33VWM 53.3VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:19,940
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Product details
Overview
SMF33AH from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for automotive-grade ESD and surge protection in power rails and signal lines. It features a 33 V working stand-off voltage, 36.7–40.6 V breakdown voltage at 1 mA, 53.3 V clamping voltage at 3.8 A peak pulse current, and 200 W peak pulse power (10/1000 µs), meeting ISO 7637-2 Pulse 1/2a/2b/3a/3b requirements for vehicle electronics.
For engineers reviewing the SMF33AH datasheet, SMF33AH pinout, SMF33AH application, or SMF33AH equivalent, key selection criteria include its SOD-123W package compatibility with automated assembly, AEC-Q101 qualification, sub-1 µA reverse leakage above 10 V, and verified clamping performance under fast transients in automotive infotainment, body control modules, and sensor interfaces.
Technical Context
The SMF33AH operates as a unidirectional avalanche diode, activated when reverse voltage exceeds its 36.7–40.6 V breakdown threshold to shunt transient energy to ground. Its low clamping ratio (VC/VBR ≈ 1.33) ensures minimal overvoltage stress on downstream ICs during 10/1000 µs surges up to 3.8 A.
Thermally, it delivers 33 °C/W junction-to-lead resistance and supports continuous operation from –55 °C to +175 °C junction temperature, with moisture sensitivity level 1 per J-STD-020-enabling reflow-compatible manufacturing without dry-pack handling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 33 V - Maximum continuous reverse operating voltage before clamping initiates |
| VBR @ IT=1 mA | 36.7–40.6 V - Confirmed avalanche onset range ensuring reliable turn-on margin |
| VC @ IPPM=3.8 A | 53.3 V - Clamped voltage during 10/1000 µs surge, limiting stress on protected ICs |
| PPPM | 200 W - Peak pulse power handling capability compliant with ISO 7637-2 test profiles |
| IR @ VWM | <1 µA - Negligible leakage current preserving system standby power integrity |
| TJ max | +175 °C - Extended thermal rating enabling under-hood deployment without derating |
| Package | SOD-123W - Compact 2-pin surface-mount outline with 5 mm × 5 mm copper pad thermal path |
Pinout & Package
SOD-123W is a two-terminal surface-mount package with cathode band marking polarity. Leads are matte tin-plated and solderable per J-STD-002; weight is 0.016 g.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Ground reference terminal | Connected to system ground plane to complete clamping path during transient events |
| Cathode | Protected line input | Connected to line being safeguarded (e.g., CAN_H, LIN, 12V rail); cathode band identifies this terminal |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use across temperature, humidity, and mechanical shock stress profiles |
| Photo glass passivated junction | Enhanced reliability and long-term stability under high-humidity and thermal cycling conditions |
| ISO 7637-2 compliance | Guaranteed immunity to standardized automotive electrical transients (Pulse 1/2a/2b/3a/3b) |
| Moisture sensitivity level 1 | No bake requirement prior to reflow; compatible with standard SMT production lines |
| Halogen-free construction | Meets IEC 61249-2-21, supporting RoHS-compliant and environmentally regulated designs |
Applications
| Automotive Body Control Module (BCM) | Infotainment Power Rail Protection |
|---|---|
Use Scenario: Protecting microcontroller I/O and LIN bus transceivers from load dump and inductive switching spikes in door modules and seat controllers. IC Role / Device Role / Timing Role: Unidirectional TVS clamping device placed between LIN line and ground to limit voltage excursions during battery disconnect events. Use Value: Maintains signal integrity below 53.3 V clamping level while surviving repeated 200 W pulses per ISO 7637-2 Pulse 2b. | Use Scenario: Safeguarding USB-C PD controller power inputs against ESD and conducted surges in head unit power distribution networks. IC Role / Device Role / Timing Role: Standoff-rated transient suppressor on 5 V/9 V/15 V rails upstream of DC-DC converters and USB interface ICs. Use Value: Sub-1 µA leakage preserves low-power sleep states; 33 V VWM avoids false triggering during normal 12 V system operation. |
| Engine Control Unit (ECU) Sensor Interface | ADAS Camera Power Line Protection |
Use Scenario: Shielding analog sensor inputs (e.g., MAP, TPS) from ignition noise and alternator ripple-induced transients. IC Role / Device Role / Timing Role: Low-capacitance unidirectional clamp on 5 V reference or signal lines feeding ADC front-ends. Use Value: 53.3 V clamping prevents ADC saturation or latch-up; SOD-123W footprint minimizes board space near sensitive analog traces. | Use Scenario: Protecting 12 V camera module power inputs from hot-swap surges and ESD events during rear-view camera installation. IC Role / Device Role / Timing Role: Primary surge suppression element on main power feed, positioned before local LDO regulators. Use Value: 200 W PPPM rating handles worst-case hot-swap energy; AEC-Q101 qualification ensures field reliability in vibration-prone mounting locations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Littelfuse SMAJ33A | Same SOD-123 package, 33 V VWM, but 36.7–40.6 V VBR and 53.3 V VC match exactly; 1.0 W steady-state rating vs. SMF33AH's 1 W | Identical ISO 7637-2 compliance and AEC-Q101 qualification; minor thermal resistance difference (RθJA = 105 °C/W vs. 100 °C/W) | Drop-in replacement where Littelfuse supply chain preference applies; verify layout clearance for identical SOD-123W footprint |
| ON Semiconductor SMCJ33A | Higher PPPM (1500 W), larger DO-214AB package; VWM/VBR/VC values differ (33 V / 36.7–40.6 V / 53.3 V same, but rated for higher surge energy) | Used in industrial power supplies requiring higher surge margin; not suitable for space-constrained automotive PCBs due to DO-214AB size | Select only when >200 W surge capacity is required; requires PCB redesign due to different package and thermal pad layout |
Compared with SMAJ33A and SMCJ33A, the SMF33AH offers optimal balance of AEC-Q101 assurance, SOD-123W compactness, and precise 200 W/33 V rating-making it preferred for automotive modules where board area, thermal management, and qualification rigor are jointly constrained.
Availability
SMF33AH is available at Aetrix Electronics and suitable for automotive body control modules, infotainment power rails, and ADAS camera systems requiring stable component supply with full traceability and lifecycle support.
Supply support for SMF33AH 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, and rectifiers with global automotive and industrial certifications.
The SMF series was developed specifically for AEC-Q101-compliant transient suppression in automotive electronics, emphasizing low-leakage, high-clamping-efficiency, and SMT manufacturability in compact packages.
FAQ
What is the maximum clamping voltage of the SMF33AH under standard test conditions?
The SMF33AH has a maximum clamping voltage (VC) of 53.3 V when subjected to a 10/1000 µs peak pulse current of 3.8 A. This value is measured per JEDEC standards and ensures downstream ICs remain within safe operating voltage limits during transient events such as load dump or ESD. The clamping performance is consistent across the full operating temperature range of –55 °C to +175 °C.
Is the SMF33AH qualified for automotive applications?
Yes, the SMF33AH is AEC-Q101 qualified and meets ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b requirements. It undergoes rigorous stress testing including temperature cycling, humidity bias, and mechanical shock-ensuring reliability in automotive environments such as engine bays, door modules, and infotainment systems where the SMF33AH is commonly deployed.
What package type does the SMF33AH use, and is it compatible with standard reflow processes?
The SMF33AH uses the SOD-123W surface-mount package with matte tin-plated leads solderable per J-STD-002. It has moisture sensitivity level 1 per J-STD-020, meaning no baking is required before reflow. Its thermal resistance (RθJA = 100 °C/W) is validated on a 5 mm × 5 mm copper pad, making it fully compatible with standard lead-free reflow profiles used in automotive electronics manufacturing.
How does the SMF33AH compare to the SMF36AH in terms of voltage ratings and application suitability?
The SMF33AH has a 33 V working stand-off voltage and 36.7–40.6 V breakdown range, while the SMF36AH is rated for 36 V VWM and 40.0–44.2 V VBR. This 3 V offset makes the SMF33AH better suited for 33 V nominal systems or tighter-margin 12 V automotive rails where lower clamping headroom is needed. Both share identical PPPM (200 W), package (SOD-123W), and qualification (AEC-Q101), so selection depends strictly on system voltage tolerance.
Can the SMF33AH be used in bidirectional configurations?
No, the SMF33AH is a unidirectional TVS diode and must be connected with correct polarity-cathode to the protected line, anode to ground. For bidirectional protection (e.g., data lines like CAN or USB), a dedicated bidirectional part such as the SMF33CA is required. Using the SMF33AH in reverse-biased configuration will not provide symmetrical clamping and may fail to protect against positive transients on grounded lines.
SMF33AH 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):
- 33V
- Voltage - Breakdown (Min):
- 36.7V
- Voltage - Clamping (Max) @ Ipp:
- 53.3V
- Current - Peak Pulse (10/1000µs):
- 3.8A
- 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
SMF33AH FAQ
1.How can I place an order for SMF33AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF33AH 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 SMF33AH reliable?
The price and inventory of SMF33AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF33AH is usually 5 days.
3.What payment methods are accepted for SMF33AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF33AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF33AH?
SMF33AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF33AH 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 SMF33AH?
For technical support, including SMF33AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF33AH requirements.
6.How does Aetrix verify that SMF33AH is sourced from the original manufacturer or authorized distributors?
All SMF33AH 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 SMF33AH meets industry standards.
7.What is the process for return or replacement of SMF33AH?
All SMF33AH units undergo pre-shipment inspection (PSI). If there is an issue with SMF33AH, 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 SMF33AH part is unused and in its original packaging.
Return procedure for SMF33AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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