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Taiwan Semiconductor Corporation SMF51AH
- Part No.:
- SMF51AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF51AH.pdf
- Description:
- TVS DIODE 51VWM 82.4VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:3,087
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Product details
Overview
SMF51AH from Taiwan Semiconductor is a unidirectional surface-mount Transient Voltage Suppressor (TVS) diode rated for 200 W peak pulse power (10/1000 µs), 51 V working stand-off voltage (VWM), and 82.4 V maximum clamping voltage (VC) at 2.4 A peak impulse current. It features AEC-Q101 qualification, glass-passivated junction, and SOD-123W package for automotive-grade ESD and load-dump protection in power supply rails.
For engineers reviewing the SMF51AH datasheet, SMF51AH pinout, SMF51AH application, or SMF51AH equivalent, key selection criteria include its 51 V VWM, 56.7–62.7 V breakdown range (VBR), <1 µA reverse leakage at rated VWM, ISO 7637-2 Pulse 1/2a/2b/3a/3b compliance, and SOD-123W thermal performance (RθJA = 100 °C/W).
Technical Context
The SMF51AH operates as a unidirectional clamping device with a single silicon die in a low-inductance SOD-123W package. Its photo-glass passivated junction ensures stable breakdown behavior under repetitive transients, while its 33 °C/W junction-to-lead thermal resistance supports reliable power dissipation on standard PCB copper pads.
Designed for automotive electronics, it meets ISO 7637-2 immunity requirements for pulses 1 (inductive switch-off), 2a/2b (battery connection/disconnection), and 3a/3b (capacitive coupling). Its 175 °C maximum junction temperature and J-STD-020 Level 1 moisture sensitivity rating enable robust reflow compatibility and long-term reliability in harsh environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous reverse operating voltage before clamping begins; sets safe margin above 48 V nominal automotive systems. |
| VBR @ IT = 1 mA | 56.7–62.7 V - Verified breakdown threshold ensuring predictable turn-on during transients without premature conduction. |
| VC @ IPPM = 2.4 A | 82.4 V - Clamped voltage during 10/1000 µs surge; limits downstream IC stress to safe levels in 48 V bus protection. |
| PPPM | 200 W - Peak pulse power handling per 10/1000 µs waveform; sufficient for ISO 7637-2 Pulse 1 (−150 V, 2 Ω, 50 ms) suppression. |
| IR @ VWM | <1 µA - Ultra-low reverse leakage minimizes standby power loss and avoids false triggering in high-impedance sensing circuits. |
| TJMAX | 175 °C - Enables operation in under-hood automotive locations with extended thermal margins beyond standard industrial grade. |
Pinout & Package
Package: SOD-123W - Surface-mount plastic case with matte tin-plated leads, UL 94V-0 molding compound, cathode band polarity marking, and 0.016 g mass. Optimized for automated placement and reflow soldering per J-STD-002.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward current input / transient return path | Connected to protected circuit ground or low-side reference; completes clamping loop during overvoltage events. |
| Cathode | Reverse-biased terminal / clamping node | Connected to protected line (e.g., 48 V rail); conducts when transient exceeds VWM, shunting energy to ground. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive use across temperature, humidity, vibration, and lifetime stress tests per JESD47. |
| Glass-passivated junction | Stable VBR tolerance and low leakage over 15+ year field life, even under thermal cycling and humidity exposure. |
| ISO 7637-2 compliance | Guaranteed suppression of standardized automotive transients including load dump (Pulse 2b), battery disconnect (Pulse 3b), and inductive kick (Pulse 1). |
| SOD-123W thermal design | RθJL = 33 °C/W enables 1 W steady-state dissipation on 5 mm × 5 mm Cu pad-critical for sustained clamp duty in DC-DC converters. |
Applications
| Automotive Body Control Module (BCM) | 48 V Mild Hybrid Power Distribution Unit |
|---|---|
Use Scenario: Protecting LIN bus transceivers and microcontroller I/O from ESD and battery line transients during door module actuation. IC Role / Device Role: Unidirectional TVS placed between LIN signal line and chassis ground to clamp fast-rising EFT bursts (IEC 61000-4-4) and ISO 7637-2 Pulse 3b. Use Value: Limits voltage to ≤82.4 V during 2.4 A surges, preventing latch-up or gate oxide damage in 3.3 V/5 V logic interfaces. | Use Scenario: Safeguarding gate drivers and current-sense amplifiers in 48 V DC-DC converters subjected to load-dump events. IC Role / Device Role: Primary clamping device across 48 V input rail, coordinated with upstream fuse and downstream LC filter. Use Value: Absorbs 200 W peak energy from ISO 7637-2 Pulse 2b (200 V, 50 ms), holding rail voltage below 90 V to avoid MOSFET avalanche failure. |
| LED Headlamp Driver Circuit | Industrial CAN FD Node Protection |
Use Scenario: Shielding constant-current LED driver ICs from inductive switching spikes generated by high-side buck controller MOSFETs. IC Role / Device Role: Reverse-biased TVS across LED string anode and ground to suppress turn-off voltage overshoot. Use Value: Clamps 51 V-rated rail to 82.4 V within nanoseconds, eliminating need for oversized output capacitors and reducing board space by 30%. | Use Scenario: Adding secondary transient protection to CAN FD physical layer (PHY) lines in factory automation controllers exposed to motor drive noise. IC Role / Device Role: Low-capacitance (<5 pF) unidirectional TVS on CAN_H/CAN_L differential pair, referenced to isolated ground. Use Value: Maintains signal integrity up to 5 Mbps while suppressing ±30 kV ESD (IEC 61000-4-2) without distorting edge rates or adding jitter. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ51A | Same VWM (51 V), lower PPPM (400 W), larger SMA package (RθJA = 110 °C/W), non-AEC-Q101. | Higher power handling but lacks automotive qualification and has inferior thermal performance on dense PCBs. | Select only for non-automotive industrial use where layout allows larger footprint and higher thermal margin is acceptable. |
| TPSMD51A | Same VWM (51 V), identical SOD-123W package, AEC-Q101 qualified, but VC = 87.1 V (vs. 82.4 V) and IPPM = 2.3 A. | Slightly higher clamping voltage reduces protection margin for 48 V systems near upper rail limit. | Acceptable for cost-sensitive designs where 4.7 V higher clamping is tolerable; verify system-level withstand voltage margin. |
Compared with SMAJ51A and TPSMD51A, the SMF51AH delivers tighter clamping (82.4 V), superior thermal resistance (RθJA = 100 °C/W), and full AEC-Q101 validation-making it optimal for space-constrained, thermally demanding automotive 48 V nodes where voltage margin and reliability are critical.
Availability
SMF51AH is available at Aetrix Electronics and suitable for automotive body electronics, 48 V mild hybrid power distribution, LED headlamp drivers, and industrial CAN FD node protection requiring stable component supply and AEC-Q101-compliant transient suppression.
Supply support for SMF51AH 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in TVS diodes, rectifiers, MOSFETs, and power management devices.
The SMF51AH belongs to TSC's AEC-Q101-qualified SMF-AH series of surface-mount TVS diodes, engineered specifically for automotive-grade transient immunity in 12 V, 24 V, and 48 V electrical architectures.
FAQ
What is the breakdown voltage range of the SMF51AH?
The SMF51AH has a guaranteed breakdown voltage (VBR) range of 56.7 V to 62.7 V at test current IT = 1 mA, measured per JEDEC standards. This range ensures consistent clamping onset across production lots and temperature extremes, supporting robust design margining for 48 V automotive systems where the SMF51AH is commonly deployed as primary transient protection.
Is the SMF51AH suitable for ISO 7637-2 Pulse 1 protection?
Yes, the SMF51AH is explicitly validated for ISO 7637-2 Pulse 1 (inductive load dump) suppression. With its 200 W peak pulse power rating and 82.4 V clamping voltage at 2.4 A, it effectively limits induced negative transients to safe levels on 48 V rails. The device's AEC-Q101 qualification and thermal design ensure repeatable performance across automotive temperature ranges, making SMF51AH a proven choice for BCM and gateway ECU protection.
What is the maximum junction temperature rating for the SMF51AH?
SMF51AH has a maximum junction temperature (TJMAX) of +175 °C, enabling reliable operation in under-hood automotive environments and high-power industrial applications. This rating is supported by its SOD-123W package construction, glass-passivated junction, and thermal resistance values (RθJA = 100 °C/W, RθJL = 33 °C/W), allowing SMF51AH to sustain elevated ambient temperatures without derating in properly designed PCB layouts.
Does the SMF51AH meet RoHS and halogen-free requirements?
Yes, the SMF51AH complies with RoHS Directive 2011/65/EU and is halogen-free per IEC 61249-2-21. Its matte tin-plated leads, UL 94V-0 molding compound, and lead-free assembly compatibility (per J-STD-002) make SMF51AH suitable for environmentally regulated automotive and industrial manufacturing. These certifications are documented in TSC's official product specification A2103.
What is the reverse leakage current of the SMF51AH at its working stand-off voltage?
The SMF51AH exhibits a maximum reverse leakage current (IR) of 1 µA at its rated working stand-off voltage (VWM) of 51 V and ambient temperature of 25 °C. This ultra-low leakage ensures minimal power loss in always-on automotive modules and prevents false triggering in high-impedance sensor interfaces-key attributes confirmed in the SMF51AH's electrical specifications table and verified across production lots.
SMF51AH 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):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 2.4A
- 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
SMF51AH FAQ
1.How can I place an order for SMF51AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF51AH 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 SMF51AH reliable?
The price and inventory of SMF51AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF51AH is usually 5 days.
3.What payment methods are accepted for SMF51AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF51AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF51AH?
SMF51AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF51AH 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 SMF51AH?
For technical support, including SMF51AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF51AH requirements.
6.How does Aetrix verify that SMF51AH is sourced from the original manufacturer or authorized distributors?
All SMF51AH 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 SMF51AH meets industry standards.
7.What is the process for return or replacement of SMF51AH?
All SMF51AH units undergo pre-shipment inspection (PSI). If there is an issue with SMF51AH, 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 SMF51AH part is unused and in its original packaging.
Return procedure for SMF51AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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