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onsemi 1SMB51CAT3
- Part No.:
- 1SMB51CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB51CAT3.pdf
- Description:
- TVS DIODE 51VWM 82.4VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:7,511
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Product details
Overview
1SMB51CAT3 from ON Semiconductor is a bidirectional 600 W transient voltage suppressor (TVS) diode designed for parallel overvoltage protection of sensitive electronics. It features a 51 V working peak reverse voltage (VRWM), 62.7 V clamping voltage at 7.3 A peak pulse current, and sub-1 ns response time. Used in power supply input stages, automotive ECUs, and industrial I/O interfaces to absorb lightning-induced surges and ESD events.
For engineers reviewing the 1SMB51CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system DC bus voltage, VC margin below IC absolute maximum ratings, UL 497B certification for isolated loop protection, and SMB package thermal performance under repetitive surge conditions.
Technical Context
This device operates as a voltage-clamped shunt protector: when transient voltage exceeds its breakdown threshold (56.11–59.69 V at 1 mA), it avalanches into low-impedance conduction to divert surge current away from downstream circuitry. Its bidirectional symmetry enables AC line and differential signal protection without polarity concerns.
Thermal design relies on junction-to-lead resistance (40 °C/W) and lead temperature derating above 75°C; maximum ambient operation is limited to 150°C with 0.55 W DC dissipation at 25°C. The Surmetic SMB package provides void-free molding and solderable L-bend leads compatible with standard reflow profiles up to 260°C for 10 seconds.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 51 V - Minimum continuous reverse standoff voltage; must exceed protected circuit's max operating voltage to avoid leakage-induced power loss. |
| VBR (min/typ/max) | 56.11 / 59.69 / 62.7 V @ 1 mA - Ensures reliable avalanche initiation before damage occurs to downstream components. |
| VC @ IPP | 82.4 V @ 7.3 A - Clamping voltage during 1 ms 10/1000 µs surge; defines upper voltage limit seen by protected load. |
| PPK | 600 W @ 1 ms - Peak surge energy handling capacity; determines survivability against IEC 61000-4-5 Level 4 transients. |
| IR @ VRWM | < 5 µA - Low leakage preserves efficiency in high-impedance bias networks and battery-powered circuits. |
| Response Time | < 1 ns - Enables suppression before fast-rising ESD or switching noise propagates into IC inputs. |
| UL Recognition | UL 497B QVGV2 - Certified for isolated loop circuit protection; validates dielectric strength, endurance, and flammability compliance. |
Pinout & Package
Package: SMB (DO-214AA), case outline 403A, surface-mount plastic package with modified L-bend leads for enhanced pad adhesion and thermal transfer.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked side) | Anode/Cathode terminal | Bidirectional operation means both terminals function identically; no polarity marking required per spec. |
| Anode (unmarked side) | Anode/Cathode terminal | Terminal symmetry allows placement across AC lines or differential pairs without orientation constraints. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, RS-485 buses, and transformer-coupled interfaces without external diode pairing. |
| 600 W peak pulse rating | Withstands IEC 61000-4-5 combination wave surges (4 kV/2 Ω) without degradation when properly mounted on FR-4 with minimum footprint. |
| ESD HBM Class 3 (>16 kV) | Eliminates need for additional ESD diodes in USB, CAN, or sensor interface front-ends where human contact is possible. |
| UL 497B recognition | Validates suitability for telecom and industrial isolated loop applications requiring certified surge protection per safety standards. |
| Sub-1 ns response | Minimizes voltage overshoot during nanosecond-scale ESD events, critical for protecting 3.3 V or 5 V logic inputs. |
Applications
| Industrial Power Supply Input | Automotive Body Control Module |
|---|---|
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: Shunt TVS diode clamping transient energy before it reaches primary-side controller IC and bulk capacitor. Use Value: 82.4 V clamping ensures MOSFET and controller remain below 100 V absolute maximum rating during 120 V load dump events. |
Use Scenario: LIN bus transceiver input in door module subjected to ESD and battery reversal transients. IC Role / Device Role / Timing Role: Bidirectional overvoltage clamp placed directly at transceiver pins to limit voltage excursions during ±25 kV contact discharge. Use Value: Sub-1 ns response prevents latch-up in LIN PHY ICs; UL 497B certification supports automotive functional safety documentation. |
| Medical Equipment Isolated Interface | Telecom DSL Line Card |
Use Scenario: Signal isolation barrier between patient-connected analog front-end and digital processing unit in ECG monitor. IC Role / Device Role / Timing Role: Transient suppressor on secondary side of isolated DC-DC converter, protecting ADC reference and op-amp inputs. Use Value: UL 497B recognition confirms compliance with medical isolation requirements; 5 µA leakage avoids measurement offset errors. |
Use Scenario: Protection of ADSL line driver/receiver pair connected to unshielded twisted-pair telephone lines. IC Role / Device Role / Timing Role: Bidirectional TVS across differential pair to suppress lightning-induced common-mode surges entering via tip/ring. Use Value: 600 W rating handles longitudinal surges per ITU-T K.20; SMB footprint allows dense placement near RJ-11 connector. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ51CA | Same VRWM (51 V) and VC (82.4 V), but lower PPK (600 W vs. 600 W); identical SMB package and UL 497B recognition. | No functional difference; SMBJ series uses same die but different branding and tape/reel packaging. | Select 1SMB51CAT3 for ON Semiconductor preferred-device status and T3 (13″ reel) logistics compatibility. |
| P6SMB51CA | Identical electrical specs and SMB package, but manufactured by STMicroelectronics; RoHS-compliant and AEC-Q200 qualified. | Preferred for automotive designs requiring AEC-Q200 qualification; same layout but different manufacturer traceability. | Choose P6SMB51CA when AEC-Q200 compliance is mandatory; otherwise 1SMB51CAT3 offers direct ON Semi support and preferred-device lifecycle assurance. |
Compared with SMBJ51CA and P6SMB51CA, the 1SMB51CAT3 provides identical clamping performance and package compatibility while offering ON Semiconductor's preferred-device designation, UL 497B certification for isolated loops, and optimized thermal resistance (40 °C/W) for high-reliability industrial deployments.
Availability
1SMB51CAT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, medical isolated interfaces, and telecom line cards requiring stable component supply and long-term manufacturing continuity.
Supply support for 1SMB51CAT3 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 energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The 1SMB51CAT3 belongs to the SMB-series transient voltage suppressor family, engineered specifically for high-energy surge immunity in harsh environments where reliability, UL certification, and fast response are critical.
FAQ
What is the clamping voltage of the 1SMB51CAT3 at its rated peak pulse current?
The 1SMB51CAT3 has a maximum clamping voltage (VC) of 82.4 V at 7.3 A peak pulse current (IPP), measured under the standard 10/1000 µs waveform. This value defines the highest voltage that will appear across protected circuitry during a full-rated surge event, ensuring downstream components remain within safe operating limits. The 1SMB51CAT3 maintains this clamping performance consistently across its specified temperature range and lifetime.
Is the 1SMB51CAT3 suitable for bidirectional AC signal protection?
Yes, the 1SMB51CAT3 is explicitly designed as a bidirectional TVS diode, making it ideal for protecting AC-coupled or differential interfaces such as RS-485, CAN FD, and telecom line pairs. Its symmetrical breakdown behavior ensures equal clamping in both polarities without requiring external diode bridges. The 1SMB51CAT3 achieves this with no polarity marking and matched VBR min/typ/max values in either direction.
Does the 1SMB51CAT3 meet UL safety standards for isolated circuit protection?
Yes, the 1SMB51CAT3 carries UL 497B recognition under file QVGV2, specifically qualifying it for use in isolated loop circuit protection. This certification covers rigorous testing including strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge performance-far exceeding basic package flammability requirements. The 1SMB51CAT3 is validated for telecom and industrial isolation barriers where regulatory compliance is mandatory.
What is the maximum operating temperature for the 1SMB51CAT3?
The 1SMB51CAT3 supports an operating and storage temperature range of –65°C to +150°C. Its thermal design centers on junction-to-lead resistance (40 °C/W), allowing sustained operation at elevated ambient temperatures when mounted on appropriate copper land patterns. At 150°C ambient, the device maintains functionality but requires derating of DC power dissipation to preserve long-term reliability-details are provided in the thermal derating curves of the official 1SMB51CAT3 datasheet.
How does the 1SMB51CAT3 compare to unidirectional TVS diodes in surge protection design?
The 1SMB51CAT3 differs fundamentally from unidirectional TVS diodes by providing symmetrical clamping for both positive and negative transients, eliminating the need for polarity-aware placement or dual-diode configurations. While unidirectional devices like 1SMB51AT3 offer slightly lower leakage in DC-biased applications, the 1SMB51CAT3 delivers superior flexibility in AC, differential, or floating systems-making it the preferred choice for RS-485, Ethernet PHY interfaces, and isolated power rails where voltage polarity is undefined or alternating.
1SMB51CAT3 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):
- 51V
- Voltage - Breakdown (Min):
- 56.7V
- Voltage - Clamping (Max) @ Ipp:
- 82.4V
- Current - Peak Pulse (10/1000µs):
- 7.3A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 175pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB51CAT3 FAQ
1.How can I place an order for 1SMB51CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB51CAT3 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 1SMB51CAT3 reliable?
The price and inventory of 1SMB51CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB51CAT3 is usually 5 days.
3.What payment methods are accepted for 1SMB51CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB51CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB51CAT3?
1SMB51CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB51CAT3 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 1SMB51CAT3?
For technical support, including 1SMB51CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB51CAT3 requirements.
6.How does Aetrix verify that 1SMB51CAT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB51CAT3 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 1SMB51CAT3 meets industry standards.
7.What is the process for return or replacement of 1SMB51CAT3?
All 1SMB51CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB51CAT3, 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 1SMB51CAT3 part is unused and in its original packaging.
Return procedure for 1SMB51CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB51CAT3 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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