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onsemi 1SMC75AT3
- Part No.:
- 1SMC75AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
1SMC75AT3.pdf
- Description:
- TVS DIODE 75VWM 121VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:5,639
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Product details
Overview
1SMC75AT3 from onsemi is a unidirectional 1500 W peak power Zener transient voltage suppressor (TVS) diode designed for parallel protection of sensitive electronics against ESD, lightning, and inductive switching surges. It features a 75 V working peak reverse voltage (VRWM), 92.1 V maximum clamping voltage at 12.4 A peak pulse current, <1 ns response time, and UL 497B recognition for isolated loop circuit protection.
For engineers reviewing the 1SMC75AT3 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, package dimensions, real-world clamping behavior, thermal derating curves, and validated alternative parts for surge protection design in automotive power supplies, industrial controls, and medical equipment interfaces.
Technical Context
The 1SMC75AT3 operates as a unidirectional Zener-based TVS diode, leveraging avalanche breakdown to clamp transients above its VRWM of 75 V. Its low dynamic impedance and sub-1 ns response ensure rapid voltage limiting during fast-rising surges such as ESD (Class 3, >16 kV HBM) and 8.3 ms half-sine surges up to 12.4 A.
Thermal performance is defined by junction-to-lead resistance of 18.3 °C/W and 4.0 W DC power dissipation at TL = 75°C, with linear derating above that temperature. The device is housed in an SMC (Case 403) surface-mount package optimized for high-surge reliability and solderability per JEDEC standards.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 1500 W @ 1 ms - sustains single high-energy transients without failure |
| Working Peak Reverse Voltage (VRWM) | 75 V - maximum continuous DC or peak AC voltage before clamping initiates |
| Clamping Voltage (VC) | 121 V @ IPP = 12.4 A - maximum voltage seen by protected circuit during specified surge |
| Breakdown Voltage (VBR) | 83.3 V (min) to 92.1 V (max) @ IT = 1 A - precise Zener conduction threshold range |
| Leakage Current (IR) | ≤5 µA @ VRWM - negligible standby power loss and signal integrity impact |
| Response Time | <1 ns - enables suppression of nanosecond-scale ESD events before downstream damage |
| ESD Rating | Class 3 (>16 kV) per Human Body Model - meets IEC 61000-4-2 Level 4 immunity requirements |
Pinout & Package
The 1SMC75AT3 is packaged in ON Semiconductor's Surmetic™ SMC (Case 403) surface-mount plastic package - void-free, thermosetting, with modified L-bend leads for enhanced pad contact area and Pb-free compatibility. Cathode is marked by a molded polarity notch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction | Connected to ground or low-side reference in unidirectional TVS configuration |
| Cathode | Current exit terminal during reverse-biased clamping | Connected to protected line; clamps to anode potential when transient exceeds VRWM |
Key Features
| Feature | Design Value |
|---|---|
| UL 497B Recognition | Qualified for isolated loop circuit protection - passes strike voltage, endurance, dielectric withstand, and discharge testing per safety standard |
| Low Clamping Ratio | VC/VRWM ≈ 1.61 - tight voltage margin between operating and clamping thresholds improves system robustness |
| High Surge Current Capacity | 12.4 A peak pulse current - handles 8.3 ms half-sine surges common in automotive load-dump and industrial switching events |
| Thermal Reliability | Rated for 260°C soldering (10 s) and −65°C to +150°C operating range - supports reflow and harsh-environment deployment |
| Pb-Free Compliance | G-suffix indicates RoHS-compliant packaging - meets global environmental regulations without performance trade-offs |
Applications
| Automotive Power Supply Protection | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protects 12 V/24 V automotive control modules from ISO 7637-2 load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional TVS placed across power rail and chassis ground to clamp surges before they reach DC-DC converters or microcontrollers. Use Value: Withstands 1500 W peak pulses and maintains clamping below 121 V, preventing overvoltage damage to downstream regulators rated ≤13.5 V input. |
Use Scenario: Shields digital input channels of programmable logic controllers from field-wiring induced surges in factory automation. IC Role / Device Role / Timing Role: Parallel-connected TVS on 24 V sensor input lines to divert transient energy away from optocouplers and level-shifting ICs. Use Value: Sub-1 ns response and 5 µA leakage preserve signal fidelity and timing margins while meeting IEC 61000-4-4 Level 3 surge immunity. |
| Medical Equipment Interface Protection | Telecom Line Card Surge Suppression |
Use Scenario: Safeguards patient-monitoring device analog front-end inputs from ESD and defibrillator-induced transients. IC Role / Device Role / Timing Role: Low-leakage TVS on signal paths between connectors and precision amplifiers to avoid offset drift or saturation. Use Value: 5 µA max IR at 75 V ensures minimal loading on high-impedance biopotential circuits; UL 497B certification validates safety-critical isolation compliance. |
Use Scenario: Installed on Ethernet or RS-485 data lines in telecom base station line cards exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Primary surge clamp on differential pairs, coordinated with GDT or MOV secondary protection stages. Use Value: 121 V clamping voltage aligns with 100BASE-TX PHY voltage tolerance; SMC package enables compact layout adjacent to RJ45 magnetics. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ75A | 600 W peak power, SMB package (smaller footprint), same VRWM (75 V), higher VC (123 V) | Limited to lower-energy transients; unsuitable for 1500 W load-dump events | Select when board space is constrained and surge energy is ≤600 W |
| 1.5SMC75A | Same 1500 W rating and SMC package, but non-Pb-free (no 'G' suffix); identical electrical specs | No regulatory distinction in function; differs only in RoHS compliance status | Choose 1SMC75AT3 for Pb-free compliance; 1.5SMC75A where legacy sourcing applies |
Compared with SMBJ75A and 1.5SMC75A, the 1SMC75AT3 uniquely combines full 1500 W surge capability, UL 497B safety certification, and Pb-free construction in the industry-standard SMC outline - making it the preferred choice for automotive, industrial, and medical designs requiring both high-reliability clamping and regulatory compliance.
Availability
1SMC75AT3 is available at Aetrix Electronics and suitable for automotive infotainment power rails, industrial PLC input modules, and medical sensor interface circuits requiring stable component supply across multi-year production cycles.
Supply support for 1SMC75AT3 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
onsemi (formerly ON Semiconductor) is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and medical markets.
The 1SMC75AT3 belongs to the SMC-series Zener TVS family, engineered specifically for high-energy transient suppression in harsh environments - emphasizing reliability, standardized surge ratings, and safety certifications like UL 497B.
FAQ
What is the clamping voltage of the 1SMC75AT3 under maximum rated surge current?
The 1SMC75AT3 has a maximum clamping voltage (VC) of 121 V when subjected to its peak pulse current (IPP) of 12.4 A, measured using the standard 8.3 ms half-sine waveform. This value is critical for ensuring protected circuitry remains within safe voltage limits during surge events. The 1SMC75AT3 datasheet specifies this parameter under controlled test conditions at TA = 25°C.
Is the 1SMC75AT3 RoHS compliant and lead-free?
Yes, the 'G' suffix in 1SMC75AT3 explicitly denotes a Pb-free (RoHS-compliant) package per onsemi's documentation. The device uses environmentally compliant materials and meets JEDEC J-STD-020 moisture sensitivity and reflow profile requirements. The 1SMC75AT3 is qualified for standard lead-free reflow soldering up to 260°C for 10 seconds.
How does the 1SMC75AT3 differ from bidirectional TVS diodes?
The 1SMC75AT3 is strictly unidirectional - it conducts only during reverse-bias overvoltage events and blocks forward current like a rectifier diode. Unlike bidirectional variants, it cannot suppress symmetrical AC transients. This makes the 1SMC75AT3 ideal for DC power rail protection where polarity is fixed, offering tighter clamping and lower leakage than equivalent bidirectional parts.
What is the thermal resistance and power derating behavior of the 1SMC75AT3?
The 1SMC75AT3 has a junction-to-lead thermal resistance (RJL) of 18.3 °C/W and provides 4.0 W DC power dissipation at TL = 75°C, derating linearly above that temperature. Its junction-to-ambient resistance (RJA) is 165 °C/W, meaning ambient temperature rise significantly impacts sustained power handling. Engineers must apply Figure 3 derating curves from the 1SMC75AT3 datasheet for accurate thermal design.
Does the 1SMC75AT3 meet any safety certifications for use in isolated systems?
Yes, the entire 1SMC5.0AT3 series - including the 1SMC75AT3 - carries UL 497B recognition (File #E210057, category QVGQ2) for protectors in isolated loop circuits. This certification confirms successful validation across strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge testing - exceeding basic flammability-only approvals held by many competitors.
1SMC75AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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):
- 12.4A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC
1SMC75AT3 FAQ
1.How can I place an order for 1SMC75AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMC75AT3 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 1SMC75AT3 reliable?
The price and inventory of 1SMC75AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMC75AT3 is usually 5 days.
3.What payment methods are accepted for 1SMC75AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMC75AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMC75AT3?
1SMC75AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMC75AT3 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 1SMC75AT3?
For technical support, including 1SMC75AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMC75AT3 requirements.
6.How does Aetrix verify that 1SMC75AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMC75AT3 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 1SMC75AT3 meets industry standards.
7.What is the process for return or replacement of 1SMC75AT3?
All 1SMC75AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMC75AT3, 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 1SMC75AT3 part is unused and in its original packaging.
Return procedure for 1SMC75AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMC75AT3 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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onsemi
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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
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DESD5V0U1BB-7
Diodes Incorporated
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D12V0L1B2LP-7B
Diodes Incorporated
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PESD2V0Y1BSFYL
Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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