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onsemi 1SMB45CAT3G
- Part No.:
- 1SMB45CAT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB45CAT3G.pdf
- Description:
- TVS DIODE 45VWM 72.2VC 425TEPBGA
- Quantity:
- Payment:
- Shipping:
Inventory:3,875
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Product details
Overview
1SMB45CAT3G 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 45 V working peak reverse voltage (VRWM), 55.3 V maximum clamping voltage at 8.3 A peak pulse current, and <1 ns response time - deployed in industrial power supplies, automotive ECUs, and communication interface circuits.
For engineers reviewing the 1SMB45CAT3G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 µs surge, UL 497B certification for isolated loop protection, low leakage (<5 µA @ 45 V), and SMB package compatibility with high-density PCB layouts.
Technical Context
The 1SMB45CAT3G operates as a voltage-clamped shunt protector: when transient voltage exceeds its breakdown threshold (52.63 V min @ 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 75 °C derated DC power (3.0 W), while its 200 pF typical junction capacitance at 0 V bias ensures minimal signal distortion in data-line applications up to ~10 MHz. The device meets AEC-Q101 stress requirements and carries UL 497B recognition for isolated loop safety compliance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Power Dissipation | 600 W @ 1 ms 10/1000 µs pulse - sustains single high-energy surges common in industrial mains and automotive load-dump events |
| Working Peak Reverse Voltage (VRWM) | 45 V - sets minimum operating voltage margin; must exceed circuit's max continuous DC or peak AC voltage |
| Breakdown Voltage (VBR) | 50.0–52.63 V @ 1 mA - defines precise avalanche initiation point for predictable clamping onset |
| Clamping Voltage (VC) | 72.2 V @ 8.3 A IPP - maximum voltage seen by protected IC during full-rated surge; critical for I/O rail survivability |
| Junction Capacitance (Cj) | 200 pF @ 0 V, 1 MHz - limits bandwidth impact on high-speed lines; suitable for RS-485, CAN, and 100BASE-TX |
| Leakage Current (IR) | <5 µA @ 45 V - negligible standby power loss and no measurable loading on 45 V bias rails |
| Response Time | <1 ns - faster than most semiconductor switches; ensures clamping before transient energy couples into IC inputs |
Pinout & Package
1SMB45CAT3G uses the SMB (DO-214AA) surface-mount package per Case 403C outline: 4.06–4.57 mm length, 3.30–3.81 mm width, 2.159 mm height, with modified L-bend leads for enhanced pad adhesion. Polarity band is omitted due to bidirectional construction.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode/Cathode (symmetrical) | Bidirectional avalanche junction | No polarity marking required; either terminal serves as input or return path depending on transient polarity |
| Case / Body | Thermal conduction path | Direct thermal coupling to PCB copper; requires minimum 25 mm² 2-oz copper pour for 3.0 W DC dissipation |
Key Features
| Feature | Design Value |
|---|---|
| UL 497B Recognition (QVGQ2) | Validated for isolated loop circuit protection - eliminates need for separate safety certification in telecom and medical isolation barriers |
| ESD Robustness | Class 3 HBM (>16 kV) - withstands repeated human-body discharges without parameter shift or failure |
| AEC-Q101 Qualified | Qualified for automotive underhood and body-control modules - validated for temperature cycling, humidity, and mechanical shock |
| Pb-Free SURMETIC® Package | RoHS-compliant thermoset molding compound with 260 °C/10 s solder tolerance - compatible with lead-free reflow profiles |
| Low Clamping Ratio (VC/VBR) | 1.37 (72.2 V / 52.63 V) - tighter voltage control vs. unidirectional TVS diodes, reducing overvoltage stress on protected ICs |
Applications
| Industrial Power Supply Input Protection | Automotive LIN Bus Transient Suppression |
|---|---|
Use Scenario: 48 V DC input stage of programmable logic controller (PLC) power module exposed to 1 kV/500 A load dump pulses. IC Role / Device Role / Timing Role: Shunt clamping element placed across bulk capacitor input, triggered within <1 ns to limit voltage to ≤72.2 V during surge. Use Value: Prevents MOSFET gate oxide rupture and UC384x controller latch-up by holding rail voltage below 80 V absolute maximum rating. |
Use Scenario: LIN transceiver node in vehicle door module subjected to ISO 7637-2 Pulse 1 (−100 V, 2 Ω source) and Pulse 2a (25 V). IC Role / Device Role / Timing Role: Bidirectional clamp between LIN bus and ground, conducting both positive and negative transients without polarity reversal. Use Value: Maintains LIN physical layer integrity by limiting bus voltage excursion to ±72.2 V, ensuring transceiver remains in functional state post-surge. |
| Medical Isolated Sensor Interface | RS-485 Data Line Surge Protection |
Use Scenario: Isolated analog front-end of patient-worn ECG monitor with reinforced insulation barrier per IEC 60601-1. IC Role / Device Role / Timing Role: UL 497B-recognized protector on secondary-side sensor signal line, referenced to isolated ground. Use Value: Enables regulatory approval of isolation barrier without additional creepage/clearance analysis - certified for 250 V RMS working voltage. |
Use Scenario: Two-wire RS-485 trunk line in factory automation network subject to induced lightning surges (IEC 61000-4-5, 2 kV line-earth). IC Role / Device Role / Timing Role: Differential-mode clamp across A/B lines, with 200 pF capacitance preserving signal edge rate for 10 Mbps operation. Use Value: Limits differential overshoot to <144 Vpp, preventing MAX1487 receiver damage while maintaining >30 dB common-mode rejection at 1 MHz. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMB45CAT3G | AEC-Q101 qualified with PPAP documentation; identical electrical specs and SMB package | Required for automotive production programs needing traceable process control and change management | Select SZ1SMB45CAT3G when OEM Tier-1 qualification mandates automotive-grade documentation and site-specific control |
| SMBJ45CA | Same VRWM and VC, but lower 600 W peak power rated at 10/1000 µs (vs. 1 ms for 1SMB45CAT3G); 150 pF Cj | Better suited for higher-frequency data lines where lower capacitance is prioritized over extreme surge duration handling | Choose SMBJ45CA for USB 2.0 or CAN FD interfaces where <150 pF is mandatory, accepting reduced 100 ms surge endurance |
Compared with SZ1SMB45CAT3G, the 1SMB45CAT3G lacks PPAP support but offers identical surge robustness and cost advantage for non-automotive use; versus SMBJ45CA, it trades 50 pF higher capacitance for superior 1 ms pulse handling - critical in power rail protection where surge duration exceeds 100 µs.
Availability
1SMB45CAT3G is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and medical isolation barriers requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.
Supply support for 1SMB45CAT3G 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, sensors, and discrete devices for automotive, industrial, and cloud-power applications.
The 1SMB45CAT3G belongs to the SMB-series TVS family engineered for high-reliability transient suppression in harsh environments - optimized for UL 497B compliance, AEC-Q101 readiness, and cost-effective surface-mount integration.
FAQ
What is the clamping voltage of the 1SMB45CAT3G at its rated peak pulse current?
The 1SMB45CAT3G has a maximum clamping voltage (VC) of 72.2 V at its rated peak pulse current (IPP) of 8.3 A, measured under the standard 10/1000 µs waveform. This value is guaranteed across temperature and represents the highest voltage the protected circuit will experience during a full-rated surge event. The 1SMB45CAT3G maintains this clamping performance with <1 ns response, ensuring downstream ICs remain within safe operating limits.
Is the 1SMB45CAT3G suitable for bidirectional signal line protection like RS-485?
Yes, the 1SMB45CAT3G is explicitly designed as a bidirectional TVS diode, making it appropriate for differential signal lines such as RS-485. Its symmetrical breakdown behavior clamps both positive and negative transients equally, and its 200 pF junction capacitance at 0 V bias allows reliable operation up to 10 Mbps without excessive signal distortion. The 1SMB45CAT3G is commonly deployed across A/B lines with series impedance matching to preserve common-mode rejection.
Does the 1SMB45CAT3G meet automotive qualification standards?
The standard 1SMB45CAT3G is not AEC-Q101 qualified; however, its automotive-grade variant SZ1SMB45CAT3G is fully AEC-Q101 qualified and PPAP capable. Both share identical electrical parameters and SMB package dimensions, but only the SZ-prefix version undergoes extended stress testing including temperature cycling, humidity bias, and mechanical shock per automotive requirements. For non-automotive applications, the 1SMB45CAT3G delivers equivalent surge protection at lower cost.
What is the maximum working voltage the 1SMB45CAT3G can protect?
The 1SMB45CAT3G has a working peak reverse voltage (VRWM) of 45 V, meaning it is rated to continuously block up to 45 V DC or peak AC voltage without significant leakage. Designers must ensure the protected circuit's maximum steady-state voltage does not exceed this value - for example, it is suitable for 36 V nominal automotive systems (peak ~44 V) or 42 V industrial DC rails. Exceeding 45 V risks premature conduction and thermal runaway.
How does UL 497B recognition benefit designs using the 1SMB45CAT3G?
UL 497B recognition certifies the 1SMB45CAT3G for use in isolated loop circuit protection - specifically validating its performance in telecom, medical, and industrial isolation barriers. This eliminates the need for system-level retesting of the isolation boundary when the 1SMB45CAT3G is used per UL guidelines. The 1SMB45CAT3G passed strike voltage, endurance conditioning, dielectric withstand, and discharge tests, enabling faster regulatory approval for products requiring reinforced insulation.
1SMB45CAT3G 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):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.2V
- Current - Peak Pulse (10/1000µs):
- 8.3A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 200pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB45CAT3G FAQ
1.How can I place an order for 1SMB45CAT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB45CAT3G 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 1SMB45CAT3G reliable?
The price and inventory of 1SMB45CAT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB45CAT3G is usually 5 days.
3.What payment methods are accepted for 1SMB45CAT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB45CAT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB45CAT3G?
1SMB45CAT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB45CAT3G 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 1SMB45CAT3G?
For technical support, including 1SMB45CAT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB45CAT3G requirements.
6.How does Aetrix verify that 1SMB45CAT3G is sourced from the original manufacturer or authorized distributors?
All 1SMB45CAT3G 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 1SMB45CAT3G meets industry standards.
7.What is the process for return or replacement of 1SMB45CAT3G?
All 1SMB45CAT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB45CAT3G, 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 1SMB45CAT3G part is unused and in its original packaging.
Return procedure for 1SMB45CAT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB45CAT3G 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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ESD5Z5.0T1G
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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