My Inquiry
My Account
Diodes Incorporated SMF4L43A-7
- Part No.:
- SMF4L43A-7
- Manufacturer:
- Diodes Incorporated
- Category:
- TVS Diodes
- Package:
- DO-219AA
- Datasheet:
-
SMF4L43A-7.pdf
- Description:
- TRANSIENT VOLTAGE SUPPRESSOR PP
- Quantity:
- Payment:
- Shipping:
Inventory:4,995
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
SMF4L43A-7 from Diodes Incorporated is a unidirectional 400W surface-mount transient voltage suppressor (TVS) diode with a 43V working peak reverse voltage, 47.8V minimum breakdown voltage, and 69.4V maximum clamping voltage at 1A surge current. It delivers fast sub-1ns response time and supports ESD protection to ±30kV (air/contact) per IEC61000-4-2, deployed in automotive power line and battery contact protection.
For engineers reviewing the SMF4L43A-7 datasheet, SMF4L43A-7 pinout, SMF4L43A-7 application, or SMF4L43A-7 equivalent, key selection criteria include clamping voltage margin versus system rail, unidirectional polarity for DC-biased lines, DO-219AA footprint compatibility, and AEC-Q qualification status for automotive use cases.
Technical Context
This TVS operates as a unidirectional avalanche clamp on DC power rails, triggering when reverse voltage exceeds 47.8V (min) and limiting transient energy with a 69.4V clamping voltage at 1A. Its 400W peak pulse power rating applies to the standard 10/1000µs waveform, and thermal resistance is 96°C/W junction-to-ambient on FR-4 PCB.
The device uses a planar silicon junction structure in a molded DO-219AA package with matte tin-plated copper alloy leads. Polarity is marked by a cathode band; it exhibits 5.7µA max reverse leakage at 43V and is rated for operation from –55°C to +175°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 400W (10/1000µs waveform; defines maximum transient energy absorption capability) |
| Working Peak Reverse Voltage (VRWM) | 43V (maximum continuous DC or RMS voltage the device blocks without conduction) |
| Breakdown Voltage (VBR min) | 47.8V @ 1mA (voltage at which avalanche conduction begins; sets overvoltage trip threshold) |
| Clamping Voltage (VC max) | 69.4V @ 1A (maximum voltage seen by protected circuit during specified surge; determines safe margin above VRWM) |
| ESD Rating | ±30kV air / ±30kV contact (IEC61000-4-2 compliance level; confirms robustness against human-body model events) |
| Response Time | <1.0ns (time from 0V to VBR under unidirectional surge; ensures protection before IC damage occurs) |
| Operating Temperature | –55°C to +175°C (enables deployment in under-hood automotive and industrial environments) |
Pinout & Package
Package: DO-219AA - ultra-compact surface-mount plastic case (2.80mm × 1.90mm × 0.60mm), halogen- and antimony-free, RoHS-compliant, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Low-side reference terminal | Connected to ground or low-potential node; completes clamping path during reverse surge |
| Cathode (marked with band) | High-side transient input terminal | Connected to protected line (e.g., 48V battery rail); avalanche conduction initiates here when VRWM exceeded |
Key Features
| Feature | Design Value |
|---|---|
| 400W peak pulse power dissipation | Enables suppression of high-energy transients (e.g., ISO 7637-2 Pulse 1/2a/5a) on 48V automotive systems |
| 69.4V clamping voltage at 1A | Provides ≥26V margin above 43V VRWM, protecting downstream 75V-rated MOSFETs and controllers |
| Sub-1ns response time | Activates before most microcontroller I/O pins or power management ICs sustain latch-up or gate oxide damage |
| ±30kV ESD immunity (IEC61000-4-2) | Eliminates need for secondary ESD protection on exposed connectors and battery terminals |
| DO-219AA footprint | Reduces PCB area by 40% vs. SMA packages while maintaining thermal performance via low RθJA (96°C/W) |
Applications
| Automotive Battery Protection | Industrial 48V DC Power Rail |
|---|---|
Use Scenario: Installed across 48V battery terminals in start-stop and mild-hybrid vehicles to suppress load dump and jump-start surges. IC Role / Device Role / Timing Role: Unidirectional TVS clamp that conducts only during negative transients relative to ground, preserving normal charging/discharging polarity. Use Value: Limits voltage to ≤69.4V during 1A surges, preventing damage to BMS analog front-ends and CAN transceivers rated for 75V absolute maximum. | Use Scenario: Placed at input of industrial 48V DC-DC converters powering PLC I/O modules and motor drivers. IC Role / Device Role / Timing Role: Primary overvoltage protector responding within <1ns to fast-rising line disturbances from relay switching or cable inductance. Use Value: Maintains system uptime by absorbing up to 400W transient energy without degradation, avoiding converter shutdown or MOSFET failure. |
| USB-C Power Delivery Interface | Telecom Base Station Power Input |
Use Scenario: Mounted on USB-C receptacle PCB near VBUS line to guard against hot-plug transients and ESD events during connector mating. IC Role / Device Role / Timing Role: Fast-acting unidirectional clamp referenced to ground, activated only when VBUS exceeds 43V during fault conditions. Use Value: Withstands ±30kV contact ESD per IEC61000-4-2, eliminating field failures caused by user-handling-induced surges. | Use Scenario: Deployed at 48V telecom rectifier output feeding remote radio units (RRUs) in outdoor base stations. IC Role / Device Role / Timing Role: High-reliability transient suppressor operating continuously at –40°C to +85°C ambient, with 175°C junction rating for thermal headroom. Use Value: Ensures >10-year field life under repeated lightning-induced surges due to low leakage (5.7µA @ 43V) and stable clamping performance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ43A | Same 43V VRWM and 69.4V VC, but in larger SMA package (RθJA = 110°C/W); 400W rating applies to same 10/1000µs waveform | Requires ~2.5× more PCB area; less suitable for space-constrained automotive modules | Select if legacy SMA footprint compatibility is required and thermal derating margin exists |
| SMF4L43CA | Bidirectional variant: identical VRWM (43V), VBR (47.8V), and VC (69.4V), but symmetrical conduction for AC-coupled or floating lines | Used where signal lines lack fixed polarity (e.g., RS-485 buses), not for DC power rails | Select only when bidirectional clamping is required; unidirectional SMF4L43A-7 is optimal for grounded 48V systems |
Compared with SMAJ43A and SMF4L43CA, SMF4L43A-7 offers superior board-space efficiency and thermal performance in DC power applications, while its unidirectional architecture avoids unnecessary conduction on non-inverting signal paths-making it the preferred choice for 48V battery and industrial supply protection.
Availability
SMF4L43A-7 is available at Aetrix Electronics and suitable for automotive battery protection, industrial 48V DC power rail conditioning, and USB-C power delivery interface hardening requiring stable component supply and long-term lifecycle support.
Supply support for SMF4L43A-7 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
Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability protection, power management, and signal integrity solutions for automotive, industrial, and computing markets.
The SMF4L series belongs to Diodes' high-power surface-mount TVS portfolio, engineered specifically for compact, high-efficiency transient suppression in next-generation 48V automotive and industrial power systems.
FAQ
What is the polarity configuration of SMF4L43A-7?
SMF4L43A-7 is a unidirectional TVS diode, with cathode denoted by a visible band on the DO-219AA package. It conducts only when reverse voltage exceeds its breakdown threshold, making it suitable for DC power lines referenced to ground. This differs from bidirectional variants like SMF4L43CA, which protect AC or floating signals.
Does SMF4L43A-7 meet AEC-Q200 requirements?
No-SMF4L43A-7 is not AEC-Q200 qualified. Diodes offers automotive-grade equivalents with Q-suffix part numbers (e.g., SMF4L43AQ-7), which undergo additional stress testing, PPAP documentation, and manufacturing in IATF 16949-certified facilities. For automotive production, the Q-suffix version must be selected.
How does the DO-219AA package affect thermal performance?
The DO-219AA package achieves a junction-to-ambient thermal resistance of 96°C/W on a 1" × 1" FR-4 board with 2 oz. copper, enabled by low-profile geometry and optimized internal thermal path. This is 14°C/W better than SMAJ43A in SMA, allowing higher sustained surge duty cycles without thermal runaway in confined spaces.
Can SMF4L43A-7 replace SMAJ43A in existing designs?
Yes-but only with layout revision. SMF4L43A-7 uses DO-219AA (2.80mm × 1.90mm), while SMAJ43A uses SMA (4.30mm × 2.60mm). Pad dimensions, solder mask openings, and thermal relief must be updated. Electrical performance is nearly identical, but the smaller footprint improves density and reduces parasitic inductance for faster transient response.
SMF4L43A-7 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Package/Case:
- DO-219AA
- Series:
- SMF4L
- 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):
- 5.7A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DO-219AA
SMF4L43A-7 FAQ
1.How can I place an order for SMF4L43A-7 through Aetrix?
Please submit a Request for Quotation (RFQ) for SMF4L43A-7 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 SMF4L43A-7 reliable?
The price and inventory of SMF4L43A-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMF4L43A-7 is usually 5 days.
3.What payment methods are accepted for SMF4L43A-7?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMF4L43A-7 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SMF4L43A-7?
SMF4L43A-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SMF4L43A-7 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 SMF4L43A-7?
For technical support, including SMF4L43A-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMF4L43A-7 requirements.
6.How does Aetrix verify that SMF4L43A-7 is sourced from the original manufacturer or authorized distributors?
All SMF4L43A-7 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 SMF4L43A-7 meets industry standards.
7.What is the process for return or replacement of SMF4L43A-7?
All SMF4L43A-7 units undergo pre-shipment inspection (PSI). If there is an issue with SMF4L43A-7, 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 SMF4L43A-7 part is unused and in its original packaging.
Return procedure for SMF4L43A-7:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SMF4L43A-7 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
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
