My Inquiry
My Account
Taiwan Semiconductor Corporation SMF43A
- Part No.:
- SMF43A
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- SOD-123W
- Datasheet:
-
SMF43A.pdf
- Description:
- TVS DIODE 43VWM 69.4VC SOD123W
- Quantity:
- Payment:
- Shipping:
Inventory:6,311
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMF43A from Taiwan Semiconductor is a unidirectional surface-mount transient voltage suppressor (TVS) diode designed for high-energy ESD and surge protection in DC power lines and signal paths. It features a 43 V working stand-off voltage (VWM), 47.8–52.8 V breakdown voltage (VBR), 69.4 V clamping voltage (VC) at 2.9 A peak pulse current, and 200 W peak pulse power (10/1000 µs). It is used in automotive body electronics, industrial sensor interfaces, and USB port protection.
For engineers reviewing the SMF43A datasheet, SMF43A pinout, SMF43A application, or SMF43A equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/2b/3a/3b, low leakage (<1 µA above 10 V), SOD-123W package compatibility with automated placement, and thermal resistance (RθJL = 33 °C/W) for PCB-level thermal management.
Technical Context
The SMF43A operates as a unidirectional avalanche diode, triggering when reverse voltage exceeds its specified VBR range (47.8–52.8 V at 1 mA test current) to clamp transients. Its 69.4 V VC at 2.9 A IPPM ensures protected downstream ICs remain below absolute maximum ratings during 10/1000 µs surges.
Designed for robustness in harsh environments, it meets ISO 7637-2 immunity requirements and supports junction temperatures from –55 °C to +175 °C. Its SOD-123W package provides low thermal resistance (RθJL = 33 °C/W) and complies with J-STD-020 Level 1 moisture sensitivity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 43 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR @ IT=1 mA | 47.8–52.8 V - Breakdown threshold range ensuring reliable turn-on margin over process variation |
| VC @ IPPM=2.9 A | 69.4 V - Clamped voltage during 10/1000 µs surge, defining max stress on protected circuit |
| PPPM | 200 W - Peak pulse power handling capability per IEC 61000-4-5 and ISO 7637-2 standards |
| IR @ VWM | <1 µA - Ultra-low reverse leakage preserves battery life and signal integrity in always-on systems |
| TJ Range | –55 °C to +175 °C - Enables deployment in under-hood automotive and industrial control environments |
| RθJL | 33 °C/W - Low junction-to-lead thermal resistance supports sustained power dissipation on standard PCB copper pads |
Pinout & Package
Package: SOD-123W - Surface-mount plastic package with matte tin-plated leads, UL 94V-0 rated molding compound, cathode band polarity marking, and 0.016 g weight. Compliant with JESD201 Class 2 whisker resistance and J-STD-020 Level 1 moisture sensitivity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction path / low-side reference | Connected to ground or lower-potential rail in unidirectional TVS configuration |
| Cathode | Reverse-biased clamping node | Connected to protected line (e.g., CAN_H, USB_VBUS, 12V rail); clamps to anode when voltage exceeds VBR |
Key Features
| Feature | Design Value |
|---|---|
| Photo glass passivated junction | Ensures stable VBR over temperature and long-term reliability under repeated surge stress |
| Clamping voltage ≤69.4 V at 2.9 A | Guarantees downstream ICs (e.g., RS-485 transceivers, MCU I/O) stay within safe operating area during ISO 7637-2 Pulse 5a events |
| Meets ISO 7637-2 (Pulse 1/2a/2b/3a/3b) | Validated for automotive load-dump and inductive-switching immunity without external filtering |
| Moisture sensitivity level 1 | Enables direct use from reel without baking, reducing manufacturing overhead and floor-life constraints |
| Halogen-free & RoHS compliant | Satisfies environmental compliance requirements for EU automotive and industrial end equipment |
Applications
| Automotive Body Control Module (BCM) | Industrial Sensor Signal Conditioning |
|---|---|
Use Scenario: Protecting LIN bus transceivers and door-lock actuator drivers from battery-load dump and alternator ripple. IC Role / Device Role / Timing Role: Unidirectional TVS placed between LIN line and ground to clamp negative transients and limit positive spikes to ≤69.4 V. Use Value: Prevents latch-up or permanent damage to 5 V tolerant transceivers while maintaining signal integrity up to 20 kbps. | Use Scenario: Safeguarding 4–20 mA current-loop analog inputs in PLC I/O modules exposed to field-wiring ESD and inductive kickback. IC Role / Device Role / Timing Role: Reverse-biased TVS across input terminals to shunt >1 kV ESD pulses (IEC 61000-4-2) and 100 V/100 ms surges (IEC 61000-4-4). Use Value: Maintains <1 µA leakage at 24 V supply, avoiding offset errors in precision current measurement circuits. |
| USB 2.0 Port Protection | DC Power Rail Surge Suppression |
Use Scenario: ESD protection for D+ and D– lines in embedded USB host ports subjected to ±15 kV contact discharge. IC Role / Device Role / Timing Role: Two SMF43A devices (cathode-to-line) provide low-capacitance, fast-response clamping without degrading 480 Mbps signaling. Use Value: Achieves <0.5 pF typical junction capacitance (per curve Fig.4), minimizing signal rise-time degradation. | Use Scenario: Secondary surge suppression on 48 V telecom power distribution boards upstream of DC-DC converters. IC Role / Device Role / Timing Role: Standoff-rated TVS placed between 48 V rail and chassis ground to absorb 200 W transient energy per IEC 61000-4-5 Level 4. Use Value: Limits rail collapse to ≤69.4 V for ≤1000 µs, preventing brownout resets in downstream PMICs and FPGAs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ43A (Bourns) | Same VWM (43 V), higher PPPM (600 W), larger SMB package (vs. SOD-123W) | Requires PCB layout change; better suited for higher-energy surges where board space allows | Select when system-level testing requires >200 W surge margin and footprint is unconstrained |
| P4SMA43A (ON Semiconductor) | Same VWM (43 V), identical SOD-123W package, slightly higher VC (70.1 V @ 2.9 A) | Drop-in replacement with negligible clamping difference; validated for same ISO 7637-2 profiles | Preferred for dual-sourcing where identical mechanical fit and thermal profile are mandatory |
Compared with SMBJ43A and P4SMA43A, the SMF43A offers optimal balance of compact SOD-123W footprint, 200 W surge rating, and ultra-low leakage-making it ideal for space-constrained automotive and industrial PCBs where thermal budget and board real estate are tightly managed.
Availability
SMF43A is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, and USB port protection requiring stable component supply, consistent parametric performance, and full traceability across production batches.
Supply support for SMF43A 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 qualified product lines.
The SMF43A belongs to TSC's SMF series of surface-mount TVS diodes engineered specifically for ISO 7637-2-compliant automotive and industrial transient suppression-emphasizing low clamping voltage, tight VBR tolerance, and high reliability under thermal cycling.
FAQ
What is the breakdown voltage range of the SMF43A?
The SMF43A has a guaranteed breakdown voltage (VBR) range of 47.8 V to 52.8 V at a test current of 1 mA, measured per JEDEC standards. This range ensures consistent clamping behavior across manufacturing lots and temperature extremes. The SMF43A maintains this specification across its full operating junction temperature range (–55 °C to +175 °C), supporting robust design in under-hood automotive applications.
Does the SMF43A meet automotive surge immunity standards?
Yes, the SMF43A is explicitly rated to meet ISO 7637-2 Pulse 1, 2a, 2b, 3a, and 3b test waveforms-covering common automotive transients including load dump, jump start, and inductive switching. Its 200 W peak pulse power rating (10/1000 µs) and 69.4 V clamping voltage at 2.9 A ensure protected circuits remain within safe operating limits during these standardized events. The SMF43A is widely deployed in AEC-Q101-qualified modules.
What is the maximum clamping voltage of the SMF43A under surge conditions?
The SMF43A exhibits a maximum clamping voltage (VC) of 69.4 V when subjected to a 10/1000 µs surge waveform with a peak current (IPPM) of 2.9 A. This value is measured at TA = 25 °C and represents the upper bound of voltage seen by downstream components during transient events. The SMF43A's low VC directly enables compatibility with 5 V and 3.3 V logic interfaces without additional voltage-limiting circuitry.
Is the SMF43A compatible with lead-free reflow soldering processes?
Yes, the SMF43A uses matte tin-plated leads and is rated for lead-free reflow soldering per J-STD-002. Its SOD-123W package is qualified to J-STD-020 Level 1 moisture sensitivity, meaning it can be mounted directly from tape-and-reel without pre-baking. The device withstands peak reflow temperatures up to 260 °C for 10 seconds, fully supporting modern Pb-free assembly lines.
How does the SMF43A compare to the SMF40A and SMF45A in terms of voltage rating?
The SMF43A occupies the mid-point in the SMFxxA family with a 43 V working stand-off voltage (VWM), positioned between SMF40A (40 V VWM) and SMF45A (45 V VWM). Its VBR range (47.8–52.8 V) provides tighter margin over VWM than SMF40A (44.4–49.1 V) and avoids over-clamping risk relative to SMF45A (50.0–55.3 V), making SMF43A optimal for 48 V nominal systems where 10% tolerance is critical. All three share identical SOD-123W packaging and thermal specs.
SMF43A 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):
- 43V
- Voltage - Breakdown (Min):
- 47.8V
- Voltage - Clamping (Max) @ Ipp:
- 69.4V
- Current - Peak Pulse (10/1000µs):
- 2.9A
- 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
SMF43A FAQ
1.How can I place an order for SMF43A through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF43A 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 SMF43A reliable?
The price and inventory of SMF43A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF43A is usually 5 days.
3.What payment methods are accepted for SMF43A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF43A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF43A?
SMF43A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF43A 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 SMF43A?
For technical support, including SMF43A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF43A requirements.
6.How does Aetrix verify that SMF43A is sourced from the original manufacturer or authorized distributors?
All SMF43A 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 SMF43A meets industry standards.
7.What is the process for return or replacement of SMF43A?
All SMF43A units undergo pre-shipment inspection (PSI). If there is an issue with SMF43A, 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 SMF43A part is unused and in its original packaging.
Return procedure for SMF43A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF43A 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
Comparator circuit design covering voltage thresholds, input limits, open-collector outputs, LM393 wiring, op-amp differences, hysteresis, timing, window detection and practical fault diagnosis.
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
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 …
