My Inquiry
My Account
Taiwan Semiconductor Corporation SMA4F51AH
- Part No.:
- SMA4F51AH
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-221AC, SMA Flat Leads
- Datasheet:
-
SMA4F51AH.pdf
- Description:
- 400W, 60V, 5%, UNIDIRECTIONAL, T
- Quantity:
- Payment:
- Shipping:
Inventory:9,475
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMA4F51AH from Taiwan Semiconductor is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode with a 51V working stand-off voltage, 57.0–63.0V breakdown voltage at 1mA, and 82.8V clamping voltage at 4.8A peak pulse current. It is AEC-Q101 qualified and designed for overvoltage protection in automotive BLDC motor drives and battery management systems.
For engineers reviewing the SMA4F51AH datasheet, SMA4F51AH pinout, SMA4F51AH application, or SMA4F51AH equivalent, key selection criteria include its 400W 10/1000μs peak pulse power rating, -55°C to +175°C operating junction temperature range, UL 94V-0 molded package, and unidirectional polarity for DC rail protection.
Technical Context
The SMA4F51AH operates as a unidirectional avalanche diode, leveraging glass-passivated junction technology for stable VBR with a maximum temperature coefficient of 0.095%/°C. Its thermal design targets PCB-mounted operation with RθJA = 62°C/W and RθJL = 20°C/W on a 5mm × 5mm copper pad.
It meets JESD201 Class 2 whisker resistance and J-STD-020 moisture sensitivity Level 1, supporting reflow-compatible assembly. The device is rated for non-repetitive 10/1000μs impulse waveforms and exhibits 1μA maximum reverse leakage at 51V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 51 V - Maximum continuous DC or RMS voltage the device blocks without conduction |
| VBR @ IT = 1 mA | 57.0–63.0 V - Verified avalanche onset range under standardized test current |
| VC @ IPPM = 4.8 A | 82.8 V - Clamped voltage during 10/1000μs surge, defining protected circuit's max stress level |
| PPPM | 400 W - Peak pulse power handling per single 10/1000μs transient event |
| TJ Range | -55°C to +175°C - Validated junction temperature window for automotive under-hood use |
| Package | Thin SMA - Surface-mount outline with cathode band marking and matte tin-plated leads |
Pinout & Package
Thin SMA package: 2-terminal SMD device with cathode band indicating terminal 2. Matte tin-plated leads meet J-STD-002 solderability; polarity is unidirectional.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (Terminal 1) | Input/Line side | Connected to protected DC rail or signal line upstream of load |
| Cathode (Terminal 2, banded) | Ground/Return side | Connected to system ground or low-impedance return path for surge current diversion |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualification | Validated for automotive-grade reliability including temperature cycling, HTRB, and ESD robustness |
| Glass-passivated junction | Ensures stable VBR and low leakage across lifetime and temperature extremes |
| UL 94V-0 molding compound | Meets flammability safety requirement for enclosed automotive and industrial enclosures |
| J-STD-020 Level 1 moisture sensitivity | Enables standard SMT reflow without baking or special handling |
Applications
| BLDC Motor Drive Protection | Battery Management System (BMS) |
|---|---|
Use Scenario: Suppresses inductive kickback and load dump transients in 48V BLDC gate driver and power stage circuits. IC Role / Device Role / Timing Role: Unidirectional TVS placed across DC bus or between gate driver output and MOSFET source. Use Value: Limits transient voltage to ≤82.8V during 4.8A surges, preventing MOSFET avalanche failure and controller latch-up. | Use Scenario: Protects cell monitor ICs and coulomb counter inputs from ESD and board-level surges in multi-cell Li-ion packs. IC Role / Device Role / Timing Role: Standoff-rated TVS on analog sensing lines (e.g., voltage taps, thermistor inputs) referenced to pack ground. Use Value: Maintains <1μA leakage at 51V, preserving BMS measurement accuracy while clamping fast transients. |
| Automotive Lighting Module | Industrial SMPS Input Stage |
Use Scenario: Shields LED driver ICs and CAN/LIN communication interfaces from load dump and jump-start surges in headlamp modules. IC Role / Device Role / Timing Role: Primary overvoltage clamp on 12V/24V supply rail upstream of DC-DC converters. Use Value: Withstands 400W 10/1000μs pulses per ISO 7637-2 Pulse 5a, enabling compliance without additional filtering. | Use Scenario: Safeguards AC-DC rectifier outputs and PFC stage inputs against lightning-induced surges in DIN-rail power supplies. IC Role / Device Role / Timing Role: Secondary TVS on bulk capacitor input, coordinated with MOVs for staged clamping. Use Value: Provides precise 51V standoff and 82.8V clamping to protect downstream SiC MOSFETs rated for 100V VDSS. |
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 SMAJ51A | Same Thin SMA package; 51V VWM, 56.7–62.7V VBR, 84.5V VC @ 4.7A; 400W rating | Identical 10/1000μs waveform rating but slightly higher clamping voltage | Preferred where Littelfuse supply chain alignment or legacy design reuse is required |
| Vishay SMA6J51A | Same package; 51V VWM, 56.7–62.7V VBR, 85.0V VC @ 4.7A; 600W rating (derated to 400W at TA > 25°C) | Higher peak power capability but requires thermal derating above ambient | Selected when higher single-pulse margin is needed and board layout allows for thermal relief |
Compared with SMA4F51AH, SMAJ51A offers tighter VBR tolerance but higher clamping, while SMA6J51A delivers greater pulse energy headroom at the cost of stricter thermal management-both require validation of leakage and clamping behavior in the target circuit.
Availability
SMA4F51AH is available at Aetrix Electronics and suitable for automotive BLDC motor drives, battery management systems, lighting modules, and industrial switching mode power supplies requiring stable component supply and AEC-Q101-compliant surge protection.
Supply support for SMA4F51AH 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 Taiwanese semiconductor manufacturer specializing in discrete power devices, TVS diodes, rectifiers, and MOSFETs for automotive and industrial markets.
The SMA4FxxAH series was developed to deliver AEC-Q101-qualified, high-power-density TVS protection in the space-constrained Thin SMA footprint for next-generation EV subsystems and smart industrial controls.
FAQ
What is the maximum clamping voltage of the SMA4F51AH under standard test conditions?
The SMA4F51AH has a maximum clamping voltage (VC) of 82.8 V when subjected to a 10/1000 μs peak pulse current of 4.8 A at TA = 25°C. This value is measured per JEDEC standards and defines the upper voltage limit imposed on protected circuitry during surge events. The SMA4F51AH maintains this clamping performance across its full operating temperature range, making it suitable for under-hood automotive applications where thermal stability is critical.
Is the SMA4F51AH suitable for bidirectional transient suppression?
No, the SMA4F51AH is a unidirectional TVS diode, indicated by its single cathode band and specified electrical parameters (e.g., forward voltage VF = 3.5 V @ 25 A). It is designed only for DC rail protection where polarity is fixed. For bidirectional AC or data-line protection, a dedicated bidirectional part such as SMA4F51AY must be used. The SMA4F51AH datasheet explicitly states "Polarity: Uni-directional", and its breakdown and clamping characteristics are validated only in the reverse direction.
What is the moisture sensitivity level (MSL) and reflow profile compatibility of the SMA4F51AH?
The SMA4F51AH is rated MSL Level 1 per J-STD-020, meaning it may be stored indefinitely at ≤30°C/60% RH and is compatible with standard lead-free reflow profiles without pre-baking. Its matte tin-plated leads meet J-STD-002 solderability requirements, and the UL 94V-0 molding compound ensures process stability. This MSL rating simplifies manufacturing logistics and eliminates dry-pack requirements for the SMA4F51AH in high-volume SMT lines.
How does the SMA4F51AH's thermal resistance support PCB-level reliability?
The SMA4F51AH specifies RθJA = 62°C/W and RθJL = 20°C/W when mounted on a 5 mm × 5 mm copper pad, enabling accurate thermal modeling for automotive and industrial designs. These values allow designers to calculate junction temperature rise under steady-state (7.5 W) and transient (400 W) conditions. The low RθJL confirms efficient heat transfer to the PCB, supporting long-term reliability in environments up to +175°C junction temperature-critical for engine bay and powertrain applications using the SMA4F51AH.
Does the SMA4F51AH comply with halogen-free and RoHS requirements?
Yes, the SMA4F51AH is RoHS compliant and halogen-free per IEC 61249-2-21. Its molding compound contains no brominated flame retardants or chlorine-based additives, and all plating and substrate materials meet EU Directive 2011/65/EU. This compliance is verified in TSC's material declarations and supports sustainability requirements for automotive OEMs and industrial equipment manufacturers specifying the SMA4F51AH.
SMA4F51AH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-221AC, SMA Flat Leads
- Series:
- SMA4F
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 51V
- Voltage - Breakdown (Min):
- 57V
- Voltage - Clamping (Max) @ Ipp:
- 82.8V
- Current - Peak Pulse (10/1000µs):
- 4.8A
- Power - Peak Pulse:
- 400W
- 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:
- Thin SMA
SMA4F51AH FAQ
1.How can I place an order for SMA4F51AH through Aetrix?
Please submit a Request for Quotation (RFQ) for SMA4F51AH 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 SMA4F51AH reliable?
The price and inventory of SMA4F51AH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMA4F51AH is usually 5 days.
3.What payment methods are accepted for SMA4F51AH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMA4F51AH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMA4F51AH?
SMA4F51AH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMA4F51AH 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 SMA4F51AH?
For technical support, including SMA4F51AH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMA4F51AH requirements.
6.How does Aetrix verify that SMA4F51AH is sourced from the original manufacturer or authorized distributors?
All SMA4F51AH 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 SMA4F51AH meets industry standards.
7.What is the process for return or replacement of SMA4F51AH?
All SMA4F51AH units undergo pre-shipment inspection (PSI). If there is an issue with SMA4F51AH, 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 SMA4F51AH part is unused and in its original packaging.
Return procedure for SMA4F51AH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMA4F51AH Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
