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onsemi 1SMB26CAT3G
- Part No.:
- 1SMB26CAT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB26CAT3G.pdf
- Description:
- TVS DIODE 26VWM 42.1VC 425TEPBGA
- Quantity:
- Payment:
- Shipping:
Inventory:35,000
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Product details
Overview
1SMB26CAT3G from ON Semiconductor is a bidirectional 600 W peak power Zener transient voltage suppressor (TVS) designed for parallel clamping protection of sensitive electronics against ESD, lightning surges, and inductive switching transients. It features a 26 V working peak reverse voltage (VRWM), 31.9 V minimum breakdown voltage (VBR) at 1 mA, 42.1 V maximum clamping voltage (VC) at 14.2 A peak pulse current (IPP), and <1 ns response time. It is widely deployed in industrial power supplies and automotive control modules.
For engineers reviewing the 1SMB26CAT3G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, UL 497B-certified isolation loop protection capability, SMB package mechanical dimensions, and validated alternatives for surge-rated overvoltage protection design.
Technical Context
The 1SMB26CAT3G operates as a bidirectional avalanche diode, leveraging Zener breakdown in both polarities to clamp transient voltages symmetrically across its terminals. Its low zener impedance (<1 Ω typical) and fast response (<1 ns) enable effective suppression of sub-microsecond transients without significant overshoot when properly laid out.
It is rated for 600 W non-repetitive peak pulse power (10/1000 µs waveform), with thermal derating starting at 75 °C junction temperature and full ambient derating above 25 °C. The device meets Class 3 ESD immunity (>16 kV HBM) and is UL 497B recognized for isolated loop circuit protection - a requirement for telecom and industrial interface ports.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 26 V - Maximum continuous reverse operating voltage before clamping begins; sets minimum system bus voltage compatibility. |
| VBR (min) | 31.9 V @ 1 mA - Guaranteed avalanche initiation threshold; ensures reliable turn-on above normal operating transients. |
| VC (max) | 42.1 V @ IPP = 14.2 A - Maximum clamped voltage during 10/1000 µs surge; defines worst-case stress on protected ICs. |
| IPP | 14.2 A - Peak pulse current supported at VRWM = 26 V; determines surge energy handling (600 W peak). |
| Ctyp | 330 pF @ 0 V, 1 MHz - Junction capacitance affecting high-frequency signal integrity; critical for data line protection. |
| IR (max) | 5 µA @ VRWM - Reverse leakage at rated working voltage; ensures minimal standby power loss and signal distortion. |
| Response Time | <1 ns - Time from transient onset to clamping conduction; enables protection of fast-edge digital and analog circuits. |
Pinout & Package
1SMB26CAT3G is housed in an SMB (DO-214AA) surface-mount plastic package per CASE 403C, featuring a void-free thermosetting body, corrosion-resistant finish, and modified L-bend leads for enhanced pad adhesion. Mounting position is unrestricted.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked band side) | Transient return path / reference node | Bidirectional operation means either terminal serves as cathode depending on polarity of transient; no polarity marking required. |
| Anode (unmarked side) | Transient return path / reference node | Functionally identical to cathode under reverse bias; symmetrical construction enables AC-coupled or floating protection. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC lines, differential buses, or ungrounded systems without polarity concerns. |
| UL 497B recognition (QVGQ2) | Validated for isolated loop circuit protection - required for telecom interfaces, PoE injectors, and industrial fieldbus ports. |
| 600 W peak pulse rating (10/1000 µs) | Supports IEC 61000-4-5 Level 4 (4 kV line-earth) surge testing with margin when combined with series impedance. |
| AEC-Q101 qualified (SZ variant) | Qualified for automotive underhood and body electronics where temperature cycling and vibration reliability are mandatory. |
| Pb-free SURMETIC™ package | RoHS-compliant molding compound with 260 °C / 10 s solderability; compatible with standard reflow profiles. |
Applications
| Industrial Power Supply Input Protection | Automotive Body Control Module (BCM) CAN Bus Protection |
|---|---|
|
Use Scenario: Protecting 24 V DC input rails in programmable logic controllers (PLCs) and motor drives from load dump and inductive kickback. IC Role / Device Role / Timing Role: Parallel-connected TVS diode providing low-impedance shunt path during >40 V transients. Use Value: Limits voltage to ≤42.1 V during 14.2 A surges, preventing damage to upstream DC-DC controllers and downstream microcontrollers. |
Use Scenario: Safeguarding CAN_H/CAN_L differential pair in vehicle BCMs against battery disconnect transients and ESD events. IC Role / Device Role / Timing Role: Bidirectional clamping element placed across differential lines to suppress common-mode and differential-mode spikes. Use Value: Maintains CAN signal integrity by clamping transients within ±42.1 V while adding only 330 pF capacitance per line. |
| Medical Equipment Isolated Sensor Interface | Point-of-Sale (POS) Terminal Ethernet Port Protection |
|
Use Scenario: Shielding isolated analog front-ends (e.g., EEG/ECG inputs) from ESD and coupling noise in Class II medical devices. IC Role / Device Role / Timing Role: UL 497B-recognized transient suppressor bridging isolated domains to meet IEC 60601-1 creepage/clearance requirements. Use Value: Provides certified overvoltage protection without compromising galvanic isolation integrity or failing flammability tests. |
Use Scenario: Hardening 10/100BASE-TX Ethernet PHY interfaces in retail POS terminals against lightning-induced surges on unshielded twisted-pair cabling. IC Role / Device Role / Timing Role: Primary-level TVS on each differential pair (TX+/TX−, RX+/RX−) to absorb common-mode surges before reaching magnetics. Use Value: Withstands 16 kV HBM ESD and 4 kV IEC 61000-4-5 surges while maintaining <1 ns response to preserve Ethernet timing margins. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMB26CAT3G | AEC-Q101 qualified; identical electrical specs but with automotive-grade traceability, PPAP documentation, and extended temperature validation. | Required for automotive OEM designs; not necessary for industrial or consumer use. | Select SZ1SMB26CAT3G when automotive qualification, lot traceability, or PPAP compliance is mandated. |
| SMBJ26CA | Same SMB package and 26 V VRWM, but lower 600 W peak power rating applies only up to 25 °C ambient; derates more aggressively above 25 °C. | Less suitable for high-temperature enclosures (e.g., under-hood automotive or sealed industrial cabinets). | Choose 1SMB26CAT3G over SMBJ26CA when sustained operation above 25 °C or UL 497B certification is required. |
Compared with SZ1SMB26CAT3G, the 1SMB26CAT3G offers identical surge performance without automotive process controls; compared with SMBJ26CA, it provides superior thermal derating and UL 497B recognition for safety-critical isolation barrier protection.
Availability
1SMB26CAT3G is available at Aetrix Electronics and suitable for industrial power supplies, automotive control units, medical sensor interfaces, and point-of-sale terminal designs requiring stable component supply and certified surge protection.
Supply support for 1SMB26CAT3G 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 solutions for automotive, industrial, and cloud power applications.
The 1SMB26CAT3G belongs to ON Semiconductor's SMB-series transient voltage suppressor family, engineered for high-energy surge clamping in space-constrained surface-mount applications demanding UL recognition and robust ESD immunity.
FAQ
What is the clamping voltage of the 1SMB26CAT3G at its rated peak pulse current?
The 1SMB26CAT3G has a maximum clamping voltage (VC) of 42.1 V when subjected to its rated peak pulse current (IPP) of 14.2 A under the standard 10/1000 µs waveform. This value is guaranteed across temperature and represents the highest voltage the device will allow to appear across protected circuitry during a surge event. The 1SMB26CAT3G maintains this clamping performance due to its low dynamic impedance and optimized Zener structure.
Is the 1SMB26CAT3G suitable for protecting RS-485 communication lines?
Yes, the 1SMB26CAT3G is suitable for RS-485 line protection when used with appropriate series current-limiting resistors or PTCs. Its 330 pF typical junction capacitance minimizes signal distortion on half-duplex or full-duplex buses up to 10 Mbps, and its bidirectional clamping handles both positive and negative transients on differential pairs. The 1SMB26CAT3G's UL 497B recognition further supports its use in safety-isolated RS-485 implementations.
Does the 1SMB26CAT3G have polarity markings, and how is it installed in-circuit?
No, the 1SMB26CAT3G does not have polarity markings because it is a bidirectional device - either terminal functions as anode or cathode depending on transient polarity. It is installed in parallel across the nodes to be protected (e.g., between VCC and GND, or across differential signal lines). The 1SMB26CAT3G's symmetrical construction eliminates orientation concerns during placement, simplifying assembly and reducing misorientation risk.
What is the maximum operating temperature range for the 1SMB26CAT3G?
The 1SMB26CAT3G is rated for an operating and storage temperature range of −65 °C to +150 °C. Its junction-to-lead thermal resistance is 25 °C/W, enabling reliable operation at elevated temperatures when mounted on adequate copper area. Derating of peak power begins at 75 °C lead temperature, and ambient derating starts at 25 °C - both defined in the official ON Semiconductor datasheet for the 1SMB26CAT3G.
How does the 1SMB26CAT3G differ from unidirectional TVS diodes like 1SMB26AT3G?
The 1SMB26CAT3G is bidirectional, meaning it clamps transients of either polarity symmetrically, making it ideal for AC-coupled, floating, or differential signal paths. In contrast, the unidirectional 1SMB26AT3G conducts only in reverse bias and blocks forward voltage - suited for DC rail protection where polarity is fixed. The 1SMB26CAT3G's bidirectional behavior is confirmed by its identical VBR min/max values in both directions and absence of polarity marking.
1SMB26CAT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 26V
- Voltage - Breakdown (Min):
- 28.9V
- Voltage - Clamping (Max) @ Ipp:
- 42.1V
- Current - Peak Pulse (10/1000µs):
- 14.2A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 330pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB26CAT3G FAQ
1.How can I place an order for 1SMB26CAT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB26CAT3G 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 1SMB26CAT3G reliable?
The price and inventory of 1SMB26CAT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB26CAT3G is usually 5 days.
3.What payment methods are accepted for 1SMB26CAT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB26CAT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB26CAT3G?
1SMB26CAT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB26CAT3G 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 1SMB26CAT3G?
For technical support, including 1SMB26CAT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB26CAT3G requirements.
6.How does Aetrix verify that 1SMB26CAT3G is sourced from the original manufacturer or authorized distributors?
All 1SMB26CAT3G 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 1SMB26CAT3G meets industry standards.
7.What is the process for return or replacement of 1SMB26CAT3G?
All 1SMB26CAT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB26CAT3G, 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 1SMB26CAT3G part is unused and in its original packaging.
Return procedure for 1SMB26CAT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB26CAT3G 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
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D12V0L1B2LP-7B
Diodes Incorporated
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PESD2V0Y1BSFYL
Nexperia USA Inc.
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DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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Diodes Incorporated
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