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onsemi 1SMB45AT3G
- Part No.:
- 1SMB45AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB45AT3G.pdf
- Description:
- TVS DIODE 45V 600W
- Quantity:
- Payment:
- Shipping:
Inventory:7,619
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Product details
Overview
1SMB45AT3G from ON Semiconductor is a unidirectional 600 W peak power Zener transient voltage suppressor (TVS) designed for parallel overvoltage protection of DC power rails and signal lines. It features a 45 V working peak reverse voltage (VRWM), 55.3 V maximum clamping voltage at 8.3 A peak pulse current, and <1.0 ns response time. It is used in automotive power supply inputs, industrial PLC I/O modules, and telecom line interface circuits to absorb ESD and lightning-induced surges.
For engineers reviewing the 1SMB45AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin relative to protected IC VMAX, peak pulse current capability under 10/1000 µs waveform, UL 497B recognition for isolated loop protection, and SMB package thermal performance in high-density PCB layouts.
Technical Context
The 1SMB45AT3G operates as a Zener-based avalanche diode, entering conduction when reverse voltage exceeds its 50.0–52.65 V breakdown range at 1.0 mA test current. Its low dynamic impedance ensures stable clamping during fast transients up to 600 W (1 ms, 10×1000 µs waveform).
It exhibits <5.0 µA leakage at 45 V VRWM and 72.7 V maximum clamping voltage at 8.3 A IPP, with junction capacitance of 385 pF at 0 V bias (1 MHz). The device meets AEC-Q101 for automotive use and carries UL 497B recognition for isolated loop circuit protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 600 W @ 1 ms (10×1000 µs waveform); sustains single high-energy surges without failure |
| Working Peak Reverse Voltage (VRWM) | 45 V; maximum continuous DC or peak AC voltage the device blocks before clamping |
| Breakdown Voltage (VBR) | 50.0–52.65 V @ IT = 1.0 mA; defines onset of avalanche conduction |
| Clamping Voltage (VC) | 72.7 V @ IPP = 8.3 A; maximum voltage seen by protected circuit during surge |
| Leakage Current | <5.0 µA @ 45 V; negligible standby power loss and signal distortion |
| Junction Capacitance | 385 pF @ 0 V, 1 MHz; impacts high-frequency signal integrity in data-line protection |
| Response Time | <1.0 ns; enables suppression of sub-nanosecond ESD events per HBM Class 3 (>16 kV) |
Pinout & Package
Package: SMB (Case 403A), surface-mount, Pb-free, void-free thermosetting plastic with modified L-bend leads and cathode polarity band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current sink during forward conduction; connected to system ground or low-side reference | Provides return path for surge current; must be routed with minimal inductance to ground plane |
| Cathode | High-voltage input terminal; connected to protected line (e.g., 48 V rail, RS-485 bus) | Accepts transient energy; polarity band ensures correct orientation during placement |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive underhood environments (−65°C to +150°C TJ) with PPAP support |
| UL 497B recognized | Approved for isolated loop circuit protection in safety-critical telecom and industrial systems |
| 600 W surge rating | Withstands IEC 61000-4-5 Level 4 (4 kV line-to-earth) surges without degradation |
| <1.0 ns response | Minimizes voltage overshoot during ESD events, reducing risk of latch-up in downstream ICs |
| SURMETIC™ package | Enhanced thermal dissipation (RJL = 25°C/W) supports high-reliability operation in compact layouts |
Applications
| Automotive Body Control Module (BCM) Power Input | Industrial PLC Analog Input Protection |
|---|---|
Use Scenario: 12 V/24 V battery-fed BCM power rail exposed to load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed between input rail and chassis ground to clamp surges above 45 V. Use Value: Limits voltage to ≤72.7 V during 8.3 A transients, protecting 48 V-rated DC-DC controllers and CAN transceivers. |
Use Scenario: 4–20 mA current loop input on programmable logic controller subjected to field wiring ESD and inductive kickback. IC Role / Device Role / Timing Role: Parallel-connected TVS across loop terminals to shunt transient energy before it reaches precision ADC front-end. Use Value: 385 pF capacitance avoids signal bandwidth reduction; <5 µA leakage preserves loop accuracy at full scale. |
| Telecom DSL Line Interface | Medical Patient Monitor ECG Lead Protection |
Use Scenario: DSL line card exposed to lightning-induced surges on twisted-pair copper lines. IC Role / Device Role / Timing Role: Primary surge protector upstream of integrated line driver/receiver ICs. Use Value: UL 497B recognition validates compliance with telecom isolation barrier requirements; 600 W rating handles Category B/C surges. |
Use Scenario: ECG electrode input stage requiring patient-isolated protection against defibrillation pulses and ESD. IC Role / Device Role / Timing Role: First-stage TVS on differential analog input, paired with series resistors and secondary filtering. Use Value: Low clamping voltage margin (72.7 V vs. typical 100 V defib pulse limit) prevents damage while maintaining diagnostic signal fidelity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ45A | Same VRWM (45 V) and VC (72.7 V), but lower 400 W peak power rating and SMA package (higher RJA) | Less suitable for repeated surges or high ambient temperature environments (>75°C) | Select when board space is constrained and surge duty cycle is infrequent |
| P6SMB45A | Identical electrical specs and SMB package, but lacks AEC-Q101 qualification and UL 497B recognition | Not approved for automotive or telecom isolated-loop safety-critical use | Select for cost-sensitive industrial controls where certification is not mandated |
Compared with SMAJ45A and P6SMB45A, the 1SMB45AT3G provides higher surge robustness (600 W vs. 400 W/600 W), automotive-grade reliability (AEC-Q101), and safety certification (UL 497B), making it optimal for mission-critical automotive, telecom, and medical applications demanding verified protection integrity.
Availability
1SMB45AT3G is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O modules, telecom line cards, and medical patient-monitoring equipment requiring stable component supply and long-term lifecycle assurance.
Supply support for 1SMB45AT3G 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 supplier specializing in power management, analog, sensor, and connectivity solutions for automotive, industrial, and cloud power applications.
The SMB-series TVS family, including 1SMB45AT3G, was engineered for high-reliability overvoltage protection in harsh environments-emphasizing low clamping, fast response, and regulatory compliance for automotive and industrial end equipment.
FAQ
What is the maximum clamping voltage of the 1SMB45AT3G at its rated peak pulse current?
The 1SMB45AT3G has a maximum clamping voltage (VC) of 72.7 V at a peak pulse current (IPP) of 8.3 A, measured using the standard 10/1000 µs waveform. This value ensures protected circuits remain below critical voltage thresholds during surge events. The 1SMB45AT3G datasheet specifies this parameter under TA = 25°C with non-repetitive pulsing, and it is validated across the full operating temperature range.
Is the 1SMB45AT3G suitable for automotive applications?
Yes, the 1SMB45AT3G is AEC-Q101 qualified and PPAP capable, confirming its suitability for automotive applications including body control modules, infotainment power supplies, and ADAS sensor interfaces. Its operating temperature range of −65°C to +150°C, robust surge handling, and SURMETIC™ package reliability meet stringent automotive environmental and lifetime requirements. The 1SMB45AT3G also supports automotive-specific traceability and change control protocols.
Does the 1SMB45AT3G have UL recognition for safety-critical protection?
Yes, the 1SMB45AT3G carries UL 497B recognition (File #E210057, QVGQ2 category) for isolated loop circuit protection. This certification covers rigorous testing including strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge performance-validating its use in telecom, industrial control, and medical systems where safety isolation is mandated. The 1SMB45AT3G is explicitly listed in ON Semiconductor's UL-certified TVS portfolio.
What is the junction capacitance of the 1SMB45AT3G, and how does it affect high-speed signal lines?
The 1SMB45AT3G has a typical junction capacitance of 385 pF at 0 V bias and 1 MHz. While acceptable for DC power rails and low-bandwidth analog signals (e.g., 4–20 mA loops), this capacitance may attenuate edges or distort waveforms above ~1 MHz. For high-speed data lines like USB or Ethernet, lower-capacitance TVS devices (e.g., <10 pF) are recommended. The 1SMB45AT3G remains appropriate for RS-485, CAN, or legacy telecom interfaces where bandwidth is limited to <10 Mbps.
How does the thermal resistance of the 1SMB45AT3G impact PCB layout design?
The 1SMB45AT3G has a junction-to-lead thermal resistance (RJL) of 25°C/W and junction-to-ambient (RJA) of 226°C/W on FR-4 with minimum footprint. To maintain reliability under repeated surges, PCB layout must maximize copper area connected to both anode and cathode pads-especially the cathode-to reduce effective RJA. Use thermal vias under pads and avoid narrow traces. The 1SMB45AT3G's SURMETIC™ package and modified L-bend leads enhance solder joint thermal transfer, but layout-driven thermal performance dominates real-world derating.
1SMB45AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 45V
- Voltage - Breakdown (Min):
- 50V
- Voltage - Clamping (Max) @ Ipp:
- 72.7V
- Current - Peak Pulse (10/1000µs):
- 8.3A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- Telecom
- Capacitance @ Frequency:
- 385pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB45AT3G FAQ
1.How can I place an order for 1SMB45AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB45AT3G 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 1SMB45AT3G reliable?
The price and inventory of 1SMB45AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB45AT3G is usually 5 days.
3.What payment methods are accepted for 1SMB45AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB45AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB45AT3G?
1SMB45AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB45AT3G 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 1SMB45AT3G?
For technical support, including 1SMB45AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB45AT3G requirements.
6.How does Aetrix verify that 1SMB45AT3G is sourced from the original manufacturer or authorized distributors?
All 1SMB45AT3G 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 1SMB45AT3G meets industry standards.
7.What is the process for return or replacement of 1SMB45AT3G?
All 1SMB45AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB45AT3G, 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 1SMB45AT3G part is unused and in its original packaging.
Return procedure for 1SMB45AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB45AT3G Tags
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