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onsemi 1SMB75AT3G
- Part No.:
- 1SMB75AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB75AT3G.pdf
- Description:
- TVS DIODE 75VWM 121VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:10,000
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Product details
Overview
1SMB75AT3G from ON Semiconductor is a unidirectional 600 W peak power Zener transient voltage suppressor (TVS) designed for parallel overvoltage protection of sensitive electronics. It features a 75 V working peak reverse voltage (VRWM), 92.1 V maximum clamping voltage at 4.9 A peak pulse current, and <1.0 ns response time - deployed in power supplies, industrial controls, and automotive ECUs to absorb ESD and lightning-induced surges.
For engineers reviewing the 1SMB75AT3G 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 @ 75 V), and SMB package compatibility with high-density PCB layouts.
Technical Context
The 1SMB75AT3G operates as a unidirectional Zener-based TVS diode, leveraging avalanche breakdown to clamp transients above its VRWM of 75 V. Its design centers on fast turn-on (<1.0 ns), low dynamic impedance, and robust 600 W non-repetitive surge capability per 1 ms pulse.
It complies with UL 497B for isolated loop circuit protection and meets AEC-Q101 stress testing requirements when ordered as SZ1SMB75AT3G. Thermal performance is defined by 226 °C/W junction-to-ambient resistance on FR-4 board with minimum footprint, and 25 °C/W junction-to-lead resistance with zero-lead-length mounting.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 75 V - Maximum continuous reverse operating voltage before clamping begins; sets minimum system DC bus rating for safe placement. |
| VBR (min) | 83.3 V @ 1 mA - Guaranteed avalanche initiation threshold; ensures reliable conduction onset during overvoltage events. |
| VC @ IPP | 121 V @ 4.9 A - Peak clamped voltage during 10/1000 µs surge; defines worst-case voltage seen by protected ICs. |
| PPK | 600 W @ 1 ms - Surge energy handling capacity; enables protection against IEC 61000-4-5 Level 4 (4 kV) surges in properly designed circuits. |
| IR @ VRWM | 5.0 µA max - Reverse leakage at rated working voltage; negligible loading on 75 V supply rails in standby. |
| Ctyp | 245 pF @ 0 V, 1 MHz - Junction capacitance affecting high-frequency signal integrity; suitable for DC/low-speed lines but not USB or HDMI. |
| Response Time | <1.0 ns - Time from transient rise to clamping onset; critical for protecting fast logic and microcontroller I/O pins. |
Pinout & Package
1SMB75AT3G uses the SMB (DO-214AA) surface-mount plastic package (Case 403A), featuring a modified L-bend lead form for enhanced pad adhesion and cathode polarity indicated by a band. Mounting is orientation-agnostic; maximum soldering temperature is 260 °C for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current sink during clamping | Connected to system ground or low-side return path; carries full surge current during transient events. |
| Cathode | Protected line connection | Connected to the line being protected (e.g., 75 V rail); voltage referenced to anode during clamping. |
Key Features
| Feature | Design Value |
|---|---|
| UL 497B Recognition | Qualified for isolated loop circuit protection - enables use in telecom interfaces, PoE injectors, and medical isolation barriers without additional certification effort. |
| AEC-Q101 Qualified Variant | SZ1SMB75AT3G version available - validated for automotive under-hood and body-control module applications with extended temperature and reliability testing. |
| ESD Robustness | Class 3 HBM (>16 kV) - withstands direct human-body ESD events without degradation, reducing need for upstream RC filtering. |
| Pb-Free Construction | RoHS-compliant SURMETIC™ package - supports lead-free reflow profiles and eliminates hazardous substance compliance risk in global manufacturing. |
| Thermal Derating Support | Defined RJA = 226 °C/W and RJL = 25 °C/W - enables accurate thermal margin calculation for high-ambient industrial deployments (e.g., motor drives). |
Applications
| Industrial Power Supply Input Protection | Automotive Body Control Module (BCM) CAN Bus Line Protection |
|---|---|
Use Scenario: 75 V DC input stage of programmable logic controller (PLC) power supply exposed to load dump and inductive switching transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed across input rail and chassis ground to clamp surges before they reach DC-DC converter ICs. Use Value: Limits transient voltage to ≤121 V, preventing damage to 100 V-rated input capacitors and primary-side MOSFETs. |
Use Scenario: Protection of 12 V CAN_H/CAN_L lines in BCM against battery reverse connection and jump-start spikes. IC Role / Device Role / Timing Role: Paired unidirectional TVS devices (one per line) referenced to ground, absorbing common-mode surges up to 600 W. Use Value: Maintains CAN signal integrity by clamping to 121 V while adding only 245 pF capacitance - well below ISO 11898-2's 500 pF limit. |
| Medical Isolated Sensor Interface | Telecom DSL Line Card Surge Protection |
Use Scenario: Secondary-side analog front-end of isolated patient-monitoring sensor interface, requiring UL 497B–compliant transient suppression. IC Role / Device Role / Timing Role: TVS placed across isolated 75 V bias rail feeding op-amps and ADC drivers to prevent latch-up from ESD coupling. Use Value: UL 497B recognition validates suitability for Class II medical equipment; <1 ns response prevents transient-induced data corruption. |
Use Scenario: Protection of ADSL/VDSL line interface ICs against lightning-induced surges entering via twisted-pair copper lines. IC Role / Device Role / Timing Role: Primary-stage unidirectional TVS on line-side transformer secondary, shunting surge energy to ground before reaching PHY IC. Use Value: 600 W peak power rating handles IEC 61000-4-5 combination wave (10/700 µs) surges up to 4 kV without failure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ75A | Lower peak power (400 W), higher clamping voltage (123 V @ 3.3 A), SMA package (smaller footprint, lower thermal mass) | Better suited for space-constrained consumer electronics; less robust for industrial 600 W surge requirements | Select when board area is critical and surge threat level is ≤IEC 61000-4-5 Level 3 (2 kV) |
| 1.5SMC75A | Same 75 V VRWM, 600 W rating, but larger SMC (DO-214AB) package with higher thermal mass and 135 V clamping voltage | Preferred for high-temperature environments (>105 °C ambient) due to superior power dissipation | Choose for automotive under-hood or industrial motor drive applications where thermal stability outweighs size constraints |
Compared with SMAJ75A, 1SMB75AT3G delivers higher surge margin (600 W vs. 400 W) and tighter clamping (121 V vs. 123 V), while offering better thermal performance than 1.5SMC75A in compact layouts due to optimized SMB thermal resistance.
Availability
1SMB75AT3G is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, medical isolated interfaces, and telecom line cards requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for 1SMB75AT3G 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 1SMB75AT3G belongs to the SMB-series unidirectional TVS family, engineered specifically for high-energy transient suppression in DC power rails and communication interfaces where reliability, UL certification, and fast response are mandatory.
FAQ
What is the maximum clamping voltage of the 1SMB75AT3G during a standard 10/1000 µs surge?
The 1SMB75AT3G exhibits a maximum clamping voltage (VC) of 121 V when subjected to its rated peak pulse current of 4.9 A under the standardized 10/1000 µs waveform. This value is guaranteed across temperature and represents the highest voltage that will appear across protected circuitry during such a surge event - critical for ensuring downstream components remain within their absolute maximum ratings.
Is the 1SMB75AT3G suitable for bidirectional signal line protection like RS-485 or CAN?
No, the 1SMB75AT3G is strictly unidirectional and must be used with correct polarity - cathode to the protected line, anode to ground. For bidirectional lines such as RS-485 or CAN, a symmetric device like the SMBJ75CA or a paired unidirectional configuration is required. Using 1SMB75AT3G on AC-coupled or differential lines without proper biasing risks incomplete protection or forward conduction during negative transients.
Does the 1SMB75AT3G meet automotive qualification standards?
The base 1SMB75AT3G is not AEC-Q101 qualified; however, the SZ1SMB75AT3G variant - identical in electrical and mechanical specifications - is fully AEC-Q101 qualified and PPAP capable. This automotive-grade version undergoes additional stress testing including temperature cycling, humidity bias HAST, and accelerated life testing to ensure reliability in vehicle ECUs and body electronics.
What is the junction-to-ambient thermal resistance (RJA) of the 1SMB75AT3G on a standard FR-4 PCB?
The 1SMB75AT3G has a specified junction-to-ambient thermal resistance (RJA) of 226 °C/W when mounted on an FR-4 printed circuit board using ON Semiconductor's minimum recommended footprint. This value assumes natural convection cooling and is essential for calculating maximum allowable power dissipation at elevated ambient temperatures - for example, limiting average power to ~0.25 W at 100 °C ambient.
Can the 1SMB75AT3G be used in place of a 75 V Zener diode for voltage regulation?
No - the 1SMB75AT3G is optimized for transient suppression, not steady-state regulation. Its Zener breakdown (VBR min = 83.3 V) and high dynamic impedance make it unsuitable for precision voltage reference or constant-current applications. Unlike general-purpose Zeners, it lacks tight tolerance, low tempco, or guaranteed regulation current specs; use dedicated Zener regulators like the MMBZ52xx series instead.
1SMB75AT3G 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):
- 75V
- Voltage - Breakdown (Min):
- 83.3V
- Voltage - Clamping (Max) @ Ipp:
- 121V
- Current - Peak Pulse (10/1000µs):
- 4.9A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 245pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB75AT3G FAQ
1.How can I place an order for 1SMB75AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB75AT3G 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 1SMB75AT3G reliable?
The price and inventory of 1SMB75AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB75AT3G is usually 5 days.
3.What payment methods are accepted for 1SMB75AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB75AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB75AT3G?
1SMB75AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB75AT3G 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 1SMB75AT3G?
For technical support, including 1SMB75AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB75AT3G requirements.
6.How does Aetrix verify that 1SMB75AT3G is sourced from the original manufacturer or authorized distributors?
All 1SMB75AT3G 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 1SMB75AT3G meets industry standards.
7.What is the process for return or replacement of 1SMB75AT3G?
All 1SMB75AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB75AT3G, 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 1SMB75AT3G part is unused and in its original packaging.
Return procedure for 1SMB75AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB75AT3G Tags
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