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onsemi 1SMA43CAT3G
- Part No.:
- 1SMA43CAT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA43CAT3G.pdf
- Description:
- TVS DIODE 43VWM 77.4VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:6,509
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Product details
Overview
1SMA43CAT3G from onsemi is a bidirectional 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), 47.8–50.2 V breakdown voltage (VBR) at 1 mA, 70.1 V clamping voltage (VC) at 5.7 A peak pulse current, and <1 ns response time. It is used in automotive power supply protection and industrial I/O interface surge suppression.
For engineers reviewing the 1SMA43CAT3G datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM margin over operating voltage, VC vs. protected IC absolute maximum rating, junction capacitance (135 pF @ 0 V), thermal derating above 75°C, and AEC-Q101 qualification status for automotive deployment.
Technical Context
The 1SMA43CAT3G operates as a bidirectional avalanche diode, leveraging silicon PN junction physics to clamp both positive and negative transients without polarity dependence. Its low zener impedance and flat handling surface support stable mounting on FR-4 PCBs with ON Semiconductor's recommended 403B footprint.
It is rated for 400 W non-repetitive peak power (10/1000 µs waveform), with thermal resistance of 50 °C/W (junction-to-lead) and 250 °C/W (junction-to-ambient). Maximum junction temperature is +150°C, and it meets Class 3 ESD immunity (>16 kV HBM).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 43 V - Minimum reverse standoff voltage before clamping begins; must exceed circuit's max continuous operating voltage. |
| VBR @ IT=1 mA | 47.8–50.2 V - Measured breakdown range ensures consistent turn-on across production lots. |
| VC @ IPP=5.7 A | 70.1 V - Clamped voltage seen by downstream ICs during 10/1000 µs surge; defines safe margin vs. IC abs max rating. |
| IPP | 5.7 A - Peak pulse current supported at VRWM = 43 V; determines minimum surge energy (≈1.2 J) the device can absorb. |
| CJ @ 0 V, 1 MHz | 135 pF - Junction capacitance impacts high-speed signal integrity; limits use in >10 Mbps data lines unless filtered. |
| Package | SMA (Case 403D) - Surface-mount plastic package with 2.6 mm nominal width, optimized for automated placement and reflow. |
| AEC-Q101 | Qualified - Validated for automotive underhood and body electronics per stress test requirements. |
Pinout & Package
SMA (Case 403D) is a two-terminal, bidirectional surface-mount package with cathode polarity indicated by a band on one end. The device has no functional distinction between anode and cathode terminals due to symmetrical bidirectional operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Terminal 1 (Banded End) | Cathode Marking Reference | Band denotes terminal orientation only; does not define unidirectional polarity-device conducts symmetrically in both directions. |
| Terminal 2 (Opposite End) | Anode Marking Reference | Complementary terminal; identical electrical behavior to Terminal 1 under reverse or forward bias due to bidirectional Zener structure. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Protects AC-coupled or floating signal lines (e.g., RS-485, CAN FD bus) without external polarity routing. |
| 400 W peak power rating | Handles IEC 61000-4-5 Level 4 surges (4 kV line-earth) when paired with appropriate series impedance. |
| ESD rating >16 kV HBM | Eliminates need for separate ESD diodes on board-level interfaces exposed to handling or connector mating. |
| Low profile SMA package | Enables placement near connectors or IC pins with minimal PCB area (2.6 × 4.3 mm) and compatible with standard SMT pick-and-place. |
| Pb-free and RoHS compliant | Meets global environmental compliance mandates without requiring special soldering profiles beyond JEDEC J-STD-020. |
Applications
| Automotive Power Rail Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: Suppressing load dump and jump-start transients on 12 V battery-fed ECUs. IC Role / Device Role / Timing Role: Bidirectional TVS placed upstream of LDO regulators and microcontrollers to clamp spikes up to ±100 V. Use Value: Prevents latch-up or permanent damage to 5 V/3.3 V logic supplies while maintaining AEC-Q101 qualification. | Use Scenario: Protecting 24 V digital input modules from field-wiring induced surges in factory automation. IC Role / Device Role / Timing Role: Standoff device mounted at DIN-rail I/O terminal block entry point to shunt fast transients before optocoupler inputs. Use Value: Enables robust operation under IEC 61000-4-4 (EFT) and IEC 61000-4-5 (surge) without adding discrete RC filters. |
| Medical Equipment Signal Line Guarding | Telecom Interface Surge Suppression |
Use Scenario: Safeguarding isolated analog sensor inputs (e.g., ECG front-end) against ESD and defibrillator discharge coupling. IC Role / Device Role / Timing Role: Low-capacitance TVS (135 pF) placed directly at connector to limit voltage overshoot before isolation barrier. Use Value: Maintains signal fidelity in sub-mV biopotential measurements while meeting IEC 60601-1-2 ESD immunity requirements. | Use Scenario: Protecting Ethernet PHY differential pairs and POTS line interfaces from lightning-induced surges. IC Role / Device Role / Timing Role: Bidirectional TVS array element used in conjunction with common-mode chokes to suppress asymmetric and symmetric transients. Use Value: Achieves GR-1089-CORE Level 3 surge immunity (6 kV differential mode) without degrading 100BASE-TX signal integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMA43CAT3G | Identical electrical specs; includes AEC-Q101 qualification documentation and PPAP support for automotive programs. | Required for Tier 1 automotive BOMs where process control traceability is mandated. | Select SZ prefix when full PPAP documentation, site-specific change control, and extended reliability reporting are contractually required. |
| 1.5SMC43CA | Same VRWM/VBR/VC ratings but in larger SMC (DO-214AB) package; higher thermal mass (RJA = 180 °C/W vs. 250 °C/W). | Better suited for high-temperature ambient environments (>85°C) or higher average power dissipation scenarios. | Choose 1.5SMC43CA when board layout allows larger footprint and thermal performance outweighs space constraints. |
Compared with 1SMA43CAT3G, the SZ1SMA43CAT3G offers identical protection performance with added automotive process controls, while the 1.5SMC43CA trades compactness for improved thermal derating-making the former ideal for space-constrained automotive modules and the latter better for industrial power supplies with sustained ambient heat.
Availability
1SMA43CAT3G is available at Aetrix Electronics and suitable for automotive ECUs, industrial PLC I/O modules, medical sensor interfaces, and telecom line card designs requiring stable component supply and long-term lifecycle assurance.
Supply support for 1SMA43CAT3G 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.
The 1SMAxxCAT3G series belongs to onsemi's SURMETIC® TVS portfolio, engineered specifically for cost-sensitive, high-volume surge protection in automotive and industrial systems where AEC-Q101 compliance and repeatable clamping performance are mandatory.
FAQ
What is the clamping voltage of the 1SMA43CAT3G at its rated peak pulse current?
The 1SMA43CAT3G has a maximum clamping voltage (VC) of 70.1 V at 5.7 A peak pulse current (IPP), measured using the 10/1000 µs standard surge waveform. This value is guaranteed across temperature and production lot, ensuring predictable protection margin for downstream 5 V or 3.3 V logic circuits. The 1SMA43CAT3G datasheet specifies this parameter under "Electrical Characteristics" with test conditions fully defined.
Is the 1SMA43CAT3G suitable for bidirectional signal line protection such as RS-485 or CAN?
Yes, the 1SMA43CAT3G is explicitly designed as a bidirectional TVS and is commonly deployed on differential buses like RS-485 and CAN FD. Its symmetrical breakdown behavior (no anode/cathode functional distinction) allows direct placement across A/B lines without polarity concerns. The 135 pF junction capacitance at 0 V is low enough to avoid signal distortion at typical CAN bit rates (up to 5 Mbps), making the 1SMA43CAT3G a validated choice for such applications.
Does the 1SMA43CAT3G meet automotive qualification standards?
Yes, the 1SMA43CAT3G is AEC-Q101 qualified and PPAP capable. While the base part number lacks the "SZ" prefix, it shares identical die and assembly processes with the SZ1SMA43CAT3G variant. The qualification applies to the entire 1SMAxxCAT3G family per onsemi's certification scope, covering temperature cycling, humidity testing, and mechanical shock. The 1SMA43CAT3G is approved for under-hood and cabin ECU use per AEC-Q101 Rev D requirements.
What is the thermal derating behavior of the 1SMA43CAT3G above 75°C ambient?
The 1SMA43CAT3G derates linearly above 75°C ambient: its DC power dissipation drops by 20 mW/°C, reaching zero at 125°C. For pulsed operation, Figure 3 in the datasheet shows 10×1000 µs surge capability falls to ~60% of rated 400 W at 100°C ambient. These curves are measured on FR-4 boards using onsemi's minimum recommended 403B footprint. The 1SMA43CAT3G's thermal resistance (RJA = 250 °C/W) confirms sensitivity to PCB copper area and airflow.
How does the junction capacitance of the 1SMA43CAT3G affect high-speed data lines?
The 1SMA43CAT3G exhibits 135 pF typical junction capacitance at 0 V bias and 1 MHz, which introduces insertion loss and rise-time degradation on high-speed lines. At USB 2.0 speeds (480 Mbps), this capacitance may cause marginal eye closure; it is well-suited for CAN (1 Mbps), RS-485 (10 Mbps), and industrial Ethernet PHYs where signal bandwidth is below 30 MHz. The 1SMA43CAT3G datasheet provides C-V curves confirming capacitance drops to ~40 pF at 20 V reverse bias-enabling dynamic reduction in critical paths.
1SMA43CAT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 43V
- Voltage - Breakdown (Min):
- 47.8V
- Voltage - Clamping (Max) @ Ipp:
- 77.4V
- Current - Peak Pulse (10/1000µs):
- -
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 135pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA43CAT3G FAQ
1.How can I place an order for 1SMA43CAT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA43CAT3G 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 1SMA43CAT3G reliable?
The price and inventory of 1SMA43CAT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA43CAT3G is usually 5 days.
3.What payment methods are accepted for 1SMA43CAT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA43CAT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA43CAT3G?
1SMA43CAT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA43CAT3G 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 1SMA43CAT3G?
For technical support, including 1SMA43CAT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA43CAT3G requirements.
6.How does Aetrix verify that 1SMA43CAT3G is sourced from the original manufacturer or authorized distributors?
All 1SMA43CAT3G 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 1SMA43CAT3G meets industry standards.
7.What is the process for return or replacement of 1SMA43CAT3G?
All 1SMA43CAT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA43CAT3G, 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 1SMA43CAT3G part is unused and in its original packaging.
Return procedure for 1SMA43CAT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA43CAT3G Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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ESD5Z3.3T1G
onsemi
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D5V0H1B2LP-7B
Diodes Incorporated
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D5V0P1B2LP-7B
Diodes Incorporated
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DESD5V0U1BA-7
Diodes Incorporated
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ESD5Z5.0T1G
onsemi
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DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
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DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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