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onsemi 1SMB26CAT3
- Part No.:
- 1SMB26CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB26CAT3.pdf
- Description:
- TVS DIODE 26VWM 42.1VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:5,147
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Product details
Overview
1SMB26CAT3 from ON Semiconductor is a bidirectional 600 W transient voltage suppressor (TVS) diode designed for parallel overvoltage protection of sensitive electronics. It features a 26 V working peak reverse voltage (VRWM), 31.9 V clamping voltage at 14.2 A peak pulse current, and sub-1 ns response time - enabling robust surge suppression in power supply inputs and communication line interfaces.
For engineers reviewing the 1SMB26CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM matching system DC bus voltage, VC/IPP trade-off for downstream component withstand capability, UL 497B certification for isolated loop compliance, and SMB (DO-214AA) package compatibility with high-density PCB layouts.
Technical Context
The 1SMB26CAT3 operates as a bidirectional Zener-based TVS, leveraging avalanche breakdown to clamp transients above its 28.9–31.9 V breakdown range. Its low zener impedance and fast <1 ns turn-on ensure minimal overshoot during ESD or lightning-induced surges.
It is rated for 600 W non-repetitive peak power (10/1000 µs waveform), supports 5 µA max leakage at 26 V, and meets UL 497B for isolated loop circuit protection - confirming suitability for telecom and industrial signal interface protection where safety certification is mandatory.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 26 V - must be ≥ continuous operating voltage of protected circuit to avoid leakage or conduction during normal operation |
| VBR (min/typ/max) | 28.9 / 30.42 / 31.9 V @ 1 mA - defines precise avalanche onset window for predictable clamping threshold |
| VC @ IPP | 42.1 V @ 14.2 A - maximum clamped voltage seen by downstream ICs during 600 W transient event |
| PPK | 600 W @ 1 ms - peak surge energy handling capacity under standardized 10/1000 µs waveform |
| Response Time | < 1 ns - ensures clamping activation before transient edge propagates into protected circuitry |
| ESD Rating | Class 3 (>16 kV HBM) - qualifies for direct handling in unshielded assembly environments |
| UL Recognition | UL 497B (QVGV2, File #116110) - certified for use in isolated loop protection circuits per safety standard |
Pinout & Package
Package: SMB (DO-214AA), surface-mount, void-free thermosetting plastic case (Case 403A). Dimensions: 4.06 × 3.30 × 2.11 mm (L × W × H); polarity band not marked; leads solderable at 260°C for 10 s.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked end) | Anode/Cathode terminal (bidirectional) | No polarity marking; either terminal functions identically due to symmetrical Zener structure |
| Anode (unmarked end) | Anode/Cathode terminal (bidirectional) | Enables placement without orientation check; simplifies automated placement and reduces assembly error risk |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Protects AC-coupled or differential lines (e.g., RS-485, CAN, Ethernet PHY) without polarity constraints |
| UL 497B recognition | Validated for isolated loop protection - eliminates need for separate safety certification in end equipment |
| Low clamping ratio (VC/VBR ≈ 1.39) | Minimizes voltage stress on downstream components during surge events compared to higher-ratio TVS devices |
| High surge current rating (14.2 A) | Withstands IEC 61000-4-5 Level 4 (4 kV/2 Ω) surges when properly decoupled with series impedance |
| Sub-1 ns response | Reduces transient-induced logic upset or latch-up risk in high-speed digital interfaces near protected nodes |
Applications
| Industrial Power Supply Input | Automotive Body Control Module (BCM) Inputs |
|---|---|
|
Use Scenario: 24 V DC input stage of programmable logic controller (PLC) power supply exposed to load dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed across bulk input capacitor, shunting surge energy before it reaches upstream rectifier and downstream DC/DC controller. Use Value: 42.1 V clamping voltage ensures MCU and gate drivers remain below absolute maximum ratings during 12 V system load dump events. |
Use Scenario: LIN bus or sensor input lines in BCM subjected to battery transients and ESD per ISO 10605. IC Role / Device Role / Timing Role: Localized TVS at connector entry point, providing first-line defense before signal conditioning amplifiers and microcontroller GPIOs. Use Value: Bidirectional operation protects against both positive and negative polarity transients common in automotive 12 V systems. |
| Medical Equipment Isolated Signal Interface | Telecom Line Card Surge Protection |
|
Use Scenario: Isolated analog sensor interface (e.g., pressure transducer) in patient monitoring device requiring UL 497B-compliant protection. IC Role / Device Role / Timing Role: Secondary protection element on secondary side of isolation barrier, ensuring fault energy does not propagate across reinforced insulation. Use Value: UL 497B recognition validates safe use in medically isolated circuits without additional external certification burden. |
Use Scenario: T1/E1 line interface card in central office equipment exposed to lightning-induced surges per GR-1089-CORE. IC Role / Device Role / Timing Role: First-stage surge suppressor on tip/ring pair, coordinated with gas discharge tube (GDT) upstream for multi-level protection. Use Value: 600 W peak power rating enables coordination with slower GDTs while maintaining low let-through voltage for IC-level protection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ26CA | Same VRWM (26 V), identical SMB package, but lower PPK (600 W same), slightly higher VC (43.0 V @ 13.9 A) | Marginally higher clamping voltage may reduce margin for 3.3 V or 5 V logic rails downstream | Select if sourcing flexibility required; verify VC margin against protected IC's absolute max rating |
| 1.5SMC27CA | Higher PPK (1500 W), DO-214AB (SMC) package (larger footprint), VRWM = 27 V, VC = 43.0 V @ 34.9 A | Requires PCB layout change; suited for higher-energy threats where 600 W is insufficient | Choose only when surge threat level exceeds IEC 61000-4-5 Level 4 or when legacy SMC footprint is fixed |
Compared with SMBJ26CA and 1.5SMC27CA, the 1SMB26CAT3 offers optimal balance of UL 497B certification, SMB footprint compatibility, and verified 42.1 V clamping performance - making it preferred for space-constrained, safety-certified industrial and medical designs where layout change is not feasible.
Availability
1SMB26CAT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive control units, medical sensor interfaces, and telecom line cards requiring stable component supply and long-term lifecycle support.
Supply support for 1SMB26CAT3 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 part of onsemi) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1SMB26CAT3 belongs to the SMB-series transient voltage suppressors - engineered specifically for high-reliability, surface-mount overvoltage protection in safety-critical and high-surge environments such as industrial controls and medical electronics.
FAQ
What is the clamping voltage of the 1SMB26CAT3 under maximum surge conditions?
The 1SMB26CAT3 has a maximum clamping voltage (VC) of 42.1 V at 14.2 A peak pulse current (IPP), measured using the standard 10/1000 µs waveform. This value represents the highest voltage that will appear across protected circuitry during a full 600 W transient event, and it is critical for verifying compatibility with downstream IC absolute maximum ratings.
Is the 1SMB26CAT3 unidirectional or bidirectional?
The 1SMB26CAT3 is a bidirectional transient voltage suppressor, meaning it provides symmetrical clamping for both positive and negative polarity transients. This is confirmed by its "C" suffix (denoting bidirectional) and absence of polarity marking on the SMB package - making it ideal for AC-coupled or differential signal lines like RS-485 or LIN bus.
Does the 1SMB26CAT3 have UL certification, and for what standard?
Yes, the 1SMB26CAT3 carries UL recognition under standard UL 497B (File #116110, QVGV2 category) for isolated loop circuit protection. This certification covers performance validation for strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge testing - confirming suitability for safety-critical telecom and medical isolation barriers.
What is the thermal resistance and derating behavior of the 1SMB26CAT3?
The 1SMB26CAT3 has a junction-to-lead thermal resistance (RJL) of 40 °C/W and junction-to-ambient (RJA) of 226 °C/W on FR-4 board. Its DC power dissipation derates linearly above 75°C (25 mW/°C) for lead temperature and above 25°C (4.4 mW/°C) for ambient temperature - requiring thermal pad design consideration in high-power or enclosed environments.
Can the 1SMB26CAT3 replace the 1SMB24CAT3 in an existing design?
Yes, the 1SMB26CAT3 can replace the 1SMB24CAT3 if the protected circuit's operating voltage is ≥26 V - since VRWM increases from 24 V to 26 V, reducing leakage risk. However, verify that the higher VBR (28.9–31.9 V vs. 26.7–29.5 V) and VC (42.1 V vs. 38.9 V) still meet downstream IC withstand requirements before substitution.
1SMB26CAT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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
1SMB26CAT3 FAQ
1.How can I place an order for 1SMB26CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB26CAT3 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 1SMB26CAT3 reliable?
The price and inventory of 1SMB26CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB26CAT3 is usually 5 days.
3.What payment methods are accepted for 1SMB26CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB26CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB26CAT3?
1SMB26CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB26CAT3 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 1SMB26CAT3?
For technical support, including 1SMB26CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB26CAT3 requirements.
6.How does Aetrix verify that 1SMB26CAT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB26CAT3 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 1SMB26CAT3 meets industry standards.
7.What is the process for return or replacement of 1SMB26CAT3?
All 1SMB26CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB26CAT3, 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 1SMB26CAT3 part is unused and in its original packaging.
Return procedure for 1SMB26CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB26CAT3 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
-
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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