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onsemi 1SMB43AT3G
- Part No.:
- 1SMB43AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB43AT3G.pdf
- Description:
- TVS DIODE 43VWM 69.4VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:12,500
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Product details
Overview
1SMB43AT3G from ON Semiconductor is a unidirectional 600 W peak power Zener transient voltage suppressor (TVS) designed for overvoltage protection in DC power rails and signal lines. It features a 43 V working peak reverse voltage (VRWM), 52.8 V minimum breakdown voltage (VBR) at 1 mA, 69.4 V maximum clamping voltage (VC) at 8.6 A peak pulse current (IPP), and <1.0 ns response time - deployed in industrial power supplies, automotive ECUs, and medical equipment input stages.
For engineers reviewing the 1SMB43AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 8.3 ms surge, UL 497B certification for isolated loop protection, low leakage (<5 µA @ 43 V), and SMB package compatibility with high-density PCB layouts.
Technical Context
The 1SMB43AT3G operates as a unidirectional Zener-based TVS diode, leveraging avalanche breakdown to clamp transients above its VRWM of 43 V. Its design targets single-pulse 8.3 ms surges per IEC 61000-4-5, with guaranteed clamping at ≤69.4 V up to 8.6 A IPP while maintaining <5 µA leakage at rated VRWM.
It uses ON Semiconductor's SURMETIC™ SMB (Case 403A) package with modified L-bend leads, rated for 260°C soldering (10 s), and meets AEC-Q101 stress requirements when ordered as SZ1SMB43AT3G. Thermal resistance is 226°C/W junction-to-ambient on FR-4 board with minimum footprint.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 43 V - Maximum continuous reverse operating voltage before clamping begins; sets minimum system bus voltage rating. |
| VBR (min) | 50.3 V @ 1 mA - Guaranteed avalanche initiation threshold; ensures reliable turn-on above normal operating voltage. |
| VC (max) | 69.4 V @ 8.6 A - Peak clamped voltage during 8.3 ms surge; defines worst-case overvoltage seen by protected ICs. |
| IPP | 8.6 A - Maximum non-repetitive peak pulse current it can safely shunt without degradation. |
| Leakage (IR) | <5.0 µA @ 43 V - Negligible standby power loss and minimal loading on sensitive reference or bias networks. |
| Response Time | <1.0 ns - Enables suppression of fast ESD and lightning-induced edges before downstream components react. |
| Junction Capacitance | 400 pF @ 0 V - Low enough for <10 MHz signal integrity preservation; suitable for DC/low-speed data lines. |
Pinout & Package
1SMB43AT3G is housed in an SMB (Case 403A) surface-mount plastic package with cathode indicated by a polarity band. The device has two terminals: anode and cathode, with no internal circuitry or active control logic.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry point during forward conduction; connected to lower-potential side of protected line. | Used only during fault conditions in reverse-biased protection configuration; not intended for sustained forward operation. |
| Cathode | Current exit point during reverse avalanche clamping; connected to higher-potential side (e.g., VBUS). | Marked with band; must be routed to rail being protected; determines orientation during PCB placement and layout. |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power | Rated for single 10/1000 µs surge events up to 600 W - sufficient for IEC 61000-4-5 Level 3 (1 kV/2 Ω) testing. |
| UL 497B recognition | Qualified for isolated loop circuit protection per Underwriters Laboratories File #E210057 - enables use in telecom and industrial safety-critical interfaces. |
| ESD robustness | Class 3 HBM (>16 kV) - withstands handling and assembly ESD without parameter shift or failure. |
| Pb-free SURMETIC™ package | RoHS-compliant SMB case with corrosion-resistant finish and solderable leads - supports lead-free reflow (260°C/10 s). |
| AEC-Q101 capability | Available as SZ1SMB43AT3G variant - qualified for automotive underhood and body electronics per stress test requirements. |
Applications
| Industrial Power Supply Input Protection | Automotive Body Control Module (BCM) CAN Bus Line Protection |
|---|---|
|
Use Scenario: Protects AC/DC adapter primary-side rectifier output and secondary-side 48 V DC bus against load dump and inductive switching spikes. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VOUT and GND to clamp positive transients exceeding 43 V. Use Value: Limits voltage excursion to ≤69.4 V during 8.3 ms surges, preventing damage to downstream DC-DC controllers and MOSFET gate drivers. |
Use Scenario: Shields CANH/CANL differential pair in BCM from battery voltage transients during jump-start or alternator load dump. IC Role / Device Role / Timing Role: One 1SMB43AT3G per line (CANH–GND, CANL–GND) providing asymmetric clamping aligned with common-mode surge paths. Use Value: Maintains CAN signal integrity with 400 pF capacitance and sub-ns response, ensuring bit error rate remains within ISO 11898-2 limits during EMC testing. |
| Medical Equipment Isolated Sensor Interface | Programmable Logic Controller (PLC) Digital Input Module |
|
Use Scenario: Guards analog front-end inputs of isolated patient monitoring sensors against ESD and defibrillator-induced transients. IC Role / Device Role / Timing Role: Placed at transformer-isolated barrier output to clamp residual surges passing through isolation. Use Value: UL 497B certification validates suitability for protected circuits in Class II medical devices, supporting regulatory submission. |
Use Scenario: Protects 24 V DC digital input channels in modular PLC backplanes from field-wiring induced surges and relay coil flyback. IC Role / Device Role / Timing Role: Mounted directly at terminal block entry point, with cathode tied to 24 V rail and anode to input pin. Use Value: 600 W surge rating handles repetitive 100 A/10 ms transients typical in factory floor environments without derating or thermal shutdown. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ43A | Same VRWM (43 V) and VC (69.4 V), but 400 W peak power (vs. 600 W); SMA package (smaller footprint, higher thermal resistance). | Limited to lower-energy surges; unsuitable for IEC 61000-4-5 Level 3+ or automotive load dump. | Select when board space is constrained and surge energy is ≤400 W; verify thermal margin on FR-4. |
| SMCJ43A | Same VRWM and VC, but 1500 W peak power; larger SMC package (Case 403D), higher mounting height and thermal mass. | Overqualified for 600 W needs; adds cost and area where 1SMB43AT3G suffices. | Choose only if future-proofing against higher surge classes or extended lifetime under repeated stress is required. |
Compared with SMAJ43A and SMCJ43A, the 1SMB43AT3G delivers optimal balance of 600 W surge capacity, SMB footprint compatibility, and UL 497B certification - making it the preferred choice for industrial and automotive applications requiring certified, mid-power transient suppression without over-engineering.
Availability
1SMB43AT3G is available at Aetrix Electronics and suitable for industrial power supplies, automotive electronic control units, and medical sensor interfaces requiring stable component supply across multi-year production cycles.
Supply support for 1SMB43AT3G 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
ON Semiconductor (now onsemi) is a global semiconductor supplier specializing in power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and medical markets.
The 1SMB43AT3G belongs to the SMB-series unidirectional TVS family, engineered specifically for robust, cost-effective overvoltage protection in high-reliability DC power and interface circuits - emphasizing clamping precision, surge endurance, and safety certification.
FAQ
What is the maximum clamping voltage of the 1SMB43AT3G under standard surge conditions?
The 1SMB43AT3G has a maximum clamping voltage (VC) of 69.4 V when subjected to its rated peak pulse current (IPP) of 8.6 A, measured using the 8.3 ms half-sine waveform defined in IEC 61000-4-5. This value is guaranteed across temperature and process variation, and appears in the Electrical Characteristics table on page 3 of the official datasheet. It defines the upper voltage limit imposed on protected circuitry during transient events.
Is the 1SMB43AT3G suitable for bidirectional signal line protection?
No, the 1SMB43AT3G is strictly unidirectional and must be used with correct polarity - cathode to the higher-potential rail, anode to ground or lower potential. For bidirectional protection (e.g., RS-485, USB D+/D−), ON Semiconductor offers the complementary 1SMB43CAT3G (bidirectional variant). Using 1SMB43AT3G on AC or differential lines risks forward conduction and failure during negative excursions.
Does the 1SMB43AT3G meet automotive qualification standards?
The base 1SMB43AT3G is not AEC-Q101 qualified; however, its automotive-grade counterpart SZ1SMB43AT3G is fully AEC-Q101 qualified and PPAP capable. Both share identical electrical specs and SMB packaging, but only the SZ-prefix version undergoes additional stress testing (temperature cycling, humidity bias, etc.) required for under-hood and chassis applications. Always specify SZ1SMB43AT3G for automotive designs.
What is the thermal resistance of the 1SMB43AT3G on a standard PCB?
The 1SMB43AT3G has a junction-to-ambient thermal resistance (RJA) of 226°C/W when mounted on an FR-4 board using ON Semiconductor's minimum recommended footprint (per Case 403A outline). This value assumes zero copper area beyond the pad; adding thermal relief or copper pour reduces RJA significantly. At 75°C ambient, its DC power dissipation derates to 0.55 W - critical for continuous leakage or low-duty-cycle surge scenarios.
How does the 1SMB43AT3G compare to the 1N6267A in terms of surge capability?
The 1SMB43AT3G provides 600 W peak pulse power in an SMB package, whereas the legacy 1N6267A (DO-201AD) delivers only 500 W in a larger through-hole package. The 1SMB43AT3G also offers lower clamping voltage (69.4 V vs. ~72 V), faster response (<1 ns vs. ~1.5 ns), and UL 497B recognition - making it superior for modern high-density, safety-certified designs. The 1N6267A lacks Pb-free compliance and AEC-Q101 variants.
1SMB43AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Bulk
- 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):
- 8.6A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 400pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB43AT3G FAQ
1.How can I place an order for 1SMB43AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB43AT3G 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 1SMB43AT3G reliable?
The price and inventory of 1SMB43AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB43AT3G is usually 5 days.
3.What payment methods are accepted for 1SMB43AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB43AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB43AT3G?
1SMB43AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB43AT3G 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 1SMB43AT3G?
For technical support, including 1SMB43AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB43AT3G requirements.
6.How does Aetrix verify that 1SMB43AT3G is sourced from the original manufacturer or authorized distributors?
All 1SMB43AT3G 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 1SMB43AT3G meets industry standards.
7.What is the process for return or replacement of 1SMB43AT3G?
All 1SMB43AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB43AT3G, 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 1SMB43AT3G part is unused and in its original packaging.
Return procedure for 1SMB43AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB43AT3G Tags
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DESD3V3E1BL-7B
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