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onsemi 1SMA43AT3G
- Part No.:
- 1SMA43AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA43AT3G.pdf
- Description:
- TVS DIODE 43VWM 69.4VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:115,000
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Product details
Overview
1SMA43AT3G from ON Semiconductor is a unidirectional 400 W peak power Zener transient voltage suppressor (TVS) designed for clamping high-energy transients in DC power rails and signal lines. It features a 43 V working peak reverse voltage (VRWM), 50.3 V nominal breakdown voltage (VBR) at 1 mA, 69.4 V clamping voltage (VC) at 5.8 A peak pulse current, and <1 ns response time - used in automotive power supply protection and industrial I/O interface surge hardening.
For engineers reviewing the 1SMA43AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM margin over operating voltage, clamping ratio (VC/VBR = 1.38), junction capacitance (295 pF @ 0 V), thermal derating above 75°C, and AEC-Q101 qualification status for automotive deployment.
Technical Context
This unidirectional TVS diode operates as a voltage-clamped shunt protector: under normal bias it presents high impedance (<2.5 µA leakage at 43 V), but triggers into low-impedance conduction when transient voltage exceeds VBR (47.8–52.8 V). Its 400 W peak power rating is defined per 10/1000 µs waveform with 1 ms pulse width.
The device uses a planar Zener junction structure in a void-free transfer-molded SMA package (Case 403D), enabling reliable 260°C soldering and flat-surface placement. Thermal resistance from junction to lead is 50°C/W, supporting 1.5 W DC dissipation at TL = 75°C with linear derating.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Working Peak Reverse Voltage (VRWM) | 43 V - maximum continuous DC or peak AC voltage the device blocks without clamping |
| Breakdown Voltage (VBR) | 47.8–52.8 V @ 1 mA - precise Zener turn-on range defining trigger threshold |
| Clamping Voltage (VC) | 69.4 V @ 5.8 A - maximum voltage seen by protected circuit during 400 W transient |
| Peak Pulse Power (PPK) | 400 W @ 1 ms - surge energy handling capability per non-repetitive 10/1000 µs waveform |
| Junction Capacitance (CJ) | 295 pF @ 0 V, 1 MHz - limits high-frequency signal integrity impact on data lines |
| ESD Rating (HBM) | Class 3 (>16 kV) - qualifies for direct ESD protection in exposed connectors and ports |
| Response Time | <1 ns - ensures clamping activation before sensitive downstream ICs experience overstress |
Pinout & Package
Package: SMA (DO-214AC), Case 403D - surface-mount, low-profile plastic package with cathode polarity band; dimensions: 4.32 mm × 2.60 mm × 2.10 mm (L × W × H); RoHS-compliant, Pb-free.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked with band) | High-side connection to protected line | Connected to the rail requiring overvoltage protection; conducts when transient exceeds VBR |
| Anode | Low-side reference (typically GND or return path) | Provides current return path during clamping; must be low-inductance to minimize VC overshoot |
Key Features
| Feature | Design Value |
|---|---|
| 400 W peak pulse power | Enables robust protection against IEC 61000-4-5 Level 4 surges (4 kV/2 Ω) on 12 V/24 V systems |
| AEC-Q101 qualified | Validated for automotive under-hood and powertrain applications with temperature cycling, HTOL, and ESD stress |
| Flat handling surface | Ensures consistent pick-and-place accuracy and coplanarity on PCBs during automated assembly |
| Low zener impedance | Maintains tight clamping across current range, minimizing voltage overshoot during fast transients |
| Pb-free SURMETIC® package | Delivers long-term reliability with corrosion-resistant finish and 260°C reflow compatibility |
Applications
| Automotive Power Rail Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: 12 V battery line in engine control unit subjected to load dump (up to 60 V, 400 ms). IC Role / Device Role / Timing Role: Shunt clamping TVS placed between battery rail and ground, triggered within <1 ns to limit voltage to ≤69.4 V. Use Value: Prevents destruction of MCU power inputs and CAN transceivers during ISO 16750-2 load dump events. |
Use Scenario: 24 V digital input channel on programmable logic controller exposed to field wiring surges. IC Role / Device Role / Timing Role: Unidirectional transient suppressor mounted at connector entry point, clamping induced spikes before optocoupler input stage. Use Value: Eliminates false triggering and extends optocoupler lifetime under IEC 61000-4-4 EFT bursts (5 kHz, 2 kV). |
| Medical Equipment Power Supply Input | Telecom Line Card Surge Protection |
Use Scenario: Secondary-side 48 V DC output of medical-grade AC/DC adapter feeding patient-monitoring analog front-end. IC Role / Device Role / Timing Role: Final-stage TVS on regulated output rail, absorbing coupling transients from internal switching noise or external ESD. Use Value: Maintains ±0.5% output regulation stability and prevents latch-up in precision ADC drivers during 15 kV HBM ESD events. |
Use Scenario: -48 V DC power feed to telecom line card in central office equipment. IC Role / Device Role / Timing Role: Primary overvoltage clamp on PSE-side power delivery, coordinated with upstream fusing and secondary TVS stages. Use Value: Limits fault voltage to safe levels during lightning-induced surges per GR-1089-CORE Zone 3 requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ43A | Same VRWM (43 V) and VC (69.4 V), but 600 W peak power in SMB package (larger footprint) | Better surge margin for infrequent high-energy events; requires PCB area increase (~30%) | Choose when system-level testing shows 400 W insufficient for worst-case surge profiles |
| 1.5SMC43A | Same electrical specs, but DO-214AB (SMC) package: 7.11 mm × 6.22 mm vs. SMA's 4.32 mm × 2.60 mm | Higher thermal mass supports longer pulse durations; incompatible with dense SMT layouts | Prefer when board space allows and thermal derating at elevated ambient temperatures is critical |
Compared with SMBJ43A and 1.5SMC43A, the 1SMA43AT3G delivers identical clamping performance in the smallest surface-mount footprint among 43 V unidirectional TVS devices, optimizing PCB real estate while maintaining AEC-Q101 compliance and 295 pF capacitance suitable for medium-speed interfaces.
Availability
1SMA43AT3G is available at Aetrix Electronics and suitable for automotive ECUs, industrial PLCs, medical power supplies, and telecom line cards requiring stable component supply with full traceability and lifecycle management.
Supply support for 1SMA43AT3G 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 is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete components for automotive, industrial, and cloud power applications.
The 1SMA43AT3G belongs to ON Semiconductor's SMA-series unidirectional TVS family, engineered for cost-effective, high-reliability transient suppression in space-constrained, high-volume applications where AEC-Q101 qualification and Pb-free compliance are mandatory.
FAQ
What is the maximum clamping voltage of the 1SMA43AT3G under rated surge conditions?
The 1SMA43AT3G has a maximum clamping voltage (VC) of 69.4 V when subjected to its rated peak pulse current of 5.8 A, measured using the standard 10/1000 µs waveform. This value is guaranteed across the full operating temperature range and defines the highest voltage the protected circuit will experience during a 400 W transient event. Engineers use this parameter to verify margin between VC and the absolute maximum ratings of downstream ICs.
Is the 1SMA43AT3G suitable for automotive applications?
Yes, the 1SMA43AT3G is AEC-Q101 qualified and PPAP capable, making it suitable for automotive applications including engine control units, body electronics, and infotainment power supplies. Its operating temperature range of −65°C to +150°C, robust surge capability, and Pb-free SURMETIC® package meet stringent automotive reliability requirements. The SZ-prefix variant (SZ1SMA43AT3G) provides additional process control for mission-critical automotive deployments.
How does the junction capacitance of the 1SMA43AT3G affect high-speed signal lines?
The 1SMA43AT3G exhibits a typical junction capacitance of 295 pF at 0 V bias and 1 MHz, which may load high-speed digital or RF signal paths. It is not recommended for USB 2.0, HDMI, or Ethernet data lines where sub-5 pF capacitance is required. Instead, it is optimized for DC power rails, RS-485 buses, and lower-frequency analog signals where its 43 V VRWM and 69.4 V clamping provide effective surge protection without compromising signal integrity.
What is the thermal derating behavior of the 1SMA43AT3G above 75°C?
The 1SMA43AT3G has a thermal resistance from junction to lead (RJL) of 50°C/W and is rated for 1.5 W DC power dissipation at TL = 75°C. Above this temperature, power dissipation must be linearly derated at 20 mW/°C. At 125°C lead temperature, maximum allowable DC power drops to 0.5 W. This derating curve is documented in Figure 5 of the official datasheet and must be applied in thermally constrained enclosures.
Can the 1SMA43AT3G replace a bidirectional TVS in AC-coupled circuits?
No, the 1SMA43AT3G is strictly unidirectional and only protects against positive transients on the cathode side relative to anode. It cannot suppress negative-going surges or AC waveforms. For bidirectional protection (e.g., RS-232, audio lines, or AC mains), a dedicated bidirectional TVS such as 1SMA43CAT3G must be used. Substituting the 1SMA43AT3G in such circuits leaves the negative half-cycle unprotected and risks device failure.
1SMA43AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AC, SMA
- 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):
- 5.8A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 295pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA43AT3G FAQ
1.How can I place an order for 1SMA43AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA43AT3G 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 1SMA43AT3G reliable?
The price and inventory of 1SMA43AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA43AT3G is usually 5 days.
3.What payment methods are accepted for 1SMA43AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA43AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA43AT3G?
1SMA43AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA43AT3G 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 1SMA43AT3G?
For technical support, including 1SMA43AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA43AT3G requirements.
6.How does Aetrix verify that 1SMA43AT3G is sourced from the original manufacturer or authorized distributors?
All 1SMA43AT3G 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 1SMA43AT3G meets industry standards.
7.What is the process for return or replacement of 1SMA43AT3G?
All 1SMA43AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA43AT3G, 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 1SMA43AT3G part is unused and in its original packaging.
Return procedure for 1SMA43AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA43AT3G Tags
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