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onsemi 1.5SMC91AT3G
- Part No.:
- 1.5SMC91AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
1.5SMC91AT3G.pdf
- Description:
- TVS DIODE 77.8V 125V SMC
- Quantity:
- Payment:
- Shipping:
Inventory:223,425
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Product details
Overview
1.5SMC91AT3G from ON Semiconductor is a unidirectional 1500 W transient voltage suppressor (TVS) diode designed for overvoltage protection in DC power rails and signal lines. It features a 77.8 V working peak reverse voltage (VRWM), 91 V nominal Zener breakdown voltage (VBR), clamps to 125 V at 12 A peak pulse current (IPP), and responds in <1.0 ns. It is widely deployed in automotive power supplies and industrial control I/O interfaces.
For engineers reviewing the 1.5SMC91AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin vs. system operating voltage, surge current capability under 1 ms pulses, UL 497B certification for isolated loop protection, and SMC package thermal performance in high-reliability PCB layouts.
Technical Context
This TVS diode operates as a unidirectional Zener-based clamp, activated only during positive transients relative to cathode. Its low dynamic impedance (<0.106 %/°C temperature coefficient of VBR) ensures stable clamping across temperature, and its <1.0 ns response time minimizes voltage overshoot before conduction begins.
The device is rated for 1500 W non-repetitive peak pulse power (10/1000 µs waveform), with thermal derating above 75°C junction temperature. It meets UL 497B for isolated loop circuit protection and carries AEC-Q101 qualification when ordered with SZ prefix - though 1.5SMC91AT3G itself is the standard industrial-grade variant.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 1500 W @ 1 ms - sustains single high-energy surges common in automotive load-dump or inductive switching events |
| Working Peak Reverse Voltage | 77.8 V - maximum continuous DC or peak AC voltage the device blocks without leakage exceeding 5 µA |
| Zener Breakdown Voltage | 91 V (nominal) @ 1 mA test current - precise threshold where avalanche conduction initiates under controlled conditions |
| Clamping Voltage | 125 V @ 12 A IPP - maximum voltage seen by protected circuit during full-rated transient event |
| Response Time | <1.0 ns - enables suppression before sensitive downstream ICs experience damaging overvoltage |
| ESD Rating | Class 3 (>16 kV HBM) - withstands human-body-model electrostatic discharge without degradation |
| UL Recognition | UL 497B QVGQ2 - certified for use in safety-critical isolated loop protection circuits per Underwriters Laboratories |
Pinout & Package
1.5SMC91AT3G is housed in the SMC (DO-214AB) surface-mount package (Case 403), measuring 7.75 × 6.60 × 2.41 mm, with modified L-bend leads for enhanced pad adhesion and void-free thermoset molding for reliability in reflow soldering up to 260°C for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current return path | Connected to system ground or lower-potential rail; conducts surge current during positive transients on cathode side |
| Cathode | Protected line connection | Connected to the line being safeguarded (e.g., 48 V bus); polarity notch on package body identifies this terminal |
Key Features
| Feature | Design Value |
|---|---|
| High Surge Capability | 1500 W peak power handling supports automotive load-dump (ISO 7637-2 Pulse 5a) and industrial lightning-induced surges |
| Low Clamping Ratio | VC/VBR = 125/91 ≈ 1.37 - tight ratio ensures minimal overvoltage margin between breakdown and clamping, improving system robustness |
| Pb-Free & RoHS Compliant | Meets global environmental regulations; compatible with lead-free reflow profiles up to 260°C |
| Fast Response & Low Inductance | <1.0 ns turn-on + optimized lead geometry reduces overshoot in high-speed transient events |
| UL 497B Certification | Validated for isolated loop protection - required for telecom, medical, and industrial safety-isolated interfaces |
Applications
| Automotive Power Supply Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: Protecting 48 V battery-fed ECUs against ISO 7637-2 load-dump transients up to 60 V peak. IC Role / Device Role / Timing Role: Unidirectional TVS placed between supply rail and chassis ground to clamp positive surges before they reach DC-DC converters. Use Value: 125 V clamping voltage provides >20% margin above 95 V load-dump peak, ensuring downstream regulators remain within absolute maximum ratings. | Use Scenario: Safeguarding 24 V digital input modules in programmable logic controllers exposed to field-wiring inductive kickback. IC Role / Device Role / Timing Role: Parallel-connected transient suppressor on each input channel, referenced to common ground. Use Value: 1500 W rating absorbs repetitive 100 A/1 ms spikes from solenoid de-energization without degradation, extending module service life. |
| Medical Equipment Isolated Interface | Telecom Line Card Surge Protection |
Use Scenario: Protecting isolated RS-485 transceivers in patient-monitoring devices connected to external sensors via long cables. IC Role / Device Role / Timing Role: TVS on both A and B differential lines, referenced to isolated ground plane per UL 497B requirements. Use Value: UL 497B recognition validates compliance with medical isolation barrier standards, enabling regulatory approval without additional system-level testing. | Use Scenario: Front-end surge protection for Ethernet PHY interfaces in DSLAM line cards subjected to lightning-induced surges on copper pairs. IC Role / Device Role / Timing Role: Bidirectional protection not supported; 1.5SMC91AT3G used on DC bias rail feeding PoE injectors to protect upstream DC-DC stages. Use Value: 77.8 V VRWM allows safe operation on 57 V PoE+ midspan outputs while clamping induced surges below 125 V - preserving MOSFET gate oxide integrity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ90A | 600 W peak power, SMB package, 90 V VBR, 139 V VC @ 4.3 A | Limited to lower-energy transients; unsuitable for automotive load-dump or industrial 10/1000 µs surges | Select when board space is constrained and surge energy is ≤600 W; verify clamping margin against system max voltage. |
| 1.5KE91A | Through-hole DO-201 package, identical 91 V VBR and 125 V VC, but 1500 W rating applies to 10/1000 µs (not 1 ms) | Requires through-hole assembly; less suitable for automated SMT production and high-density layouts | Choose for legacy through-hole designs or where thermal mass of leaded package improves sustained surge handling. |
Compared with SMBJ90A and 1.5KE91A, the 1.5SMC91AT3G delivers identical clamping performance in a compact SMC package optimized for SMT manufacturing, with verified 1500 W capability at 1 ms - making it the preferred choice for new automotive and industrial designs requiring high-energy, surface-mount transient suppression.
Availability
1.5SMC91AT3G is available at Aetrix Electronics and suitable for automotive power systems, industrial PLC I/O modules, medical isolated interfaces, and telecom line card protection requiring stable component supply and full traceability.
Supply support for 1.5SMC91AT3G 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, sensor, and discrete solutions for automotive, industrial, and cloud power applications.
The 1.5SMCxxAT3G series was engineered for high-reliability transient suppression in harsh environments - emphasizing surge robustness, UL-certified isolation compliance, and AEC-Q101 readiness for mission-critical systems.
FAQ
What is the maximum clamping voltage of the 1.5SMC91AT3G under full-rated surge conditions?
The 1.5SMC91AT3G clamps to a maximum of 125 V when subjected to its rated peak pulse current of 12 A (10/1000 µs waveform). This value is guaranteed per the datasheet's Electrical Characteristics table and defines the upper voltage limit imposed on protected circuitry during worst-case transient events. Designers must ensure this clamping level remains safely below the absolute maximum voltage rating of downstream components. The 1.5SMC91AT3G achieves this with low dynamic impedance and fast turn-on characteristics.
Is the 1.5SMC91AT3G suitable for bidirectional transient suppression?
No, the 1.5SMC91AT3G is a unidirectional TVS diode and only protects against positive-going transients on its cathode terminal. It does not suppress negative voltage excursions. For bidirectional protection, a separate device such as an SMDA91 or paired unidirectional TVS configuration is required. The datasheet explicitly states that bidirectional variants are not offered in the SMC series, and the 1.5SMC91AT3G's marking, polarity notch, and electrical specifications confirm its unidirectional functionality.
Does the 1.5SMC91AT3G meet automotive qualification standards?
The 1.5SMC91AT3G is the industrial-grade variant of the family; however, its SZ-prefix counterpart (SZ1.5SMC91AT3G) is AEC-Q101 qualified and PPAP capable. While the 1.5SMC91AT3G shares identical electrical and mechanical specifications, it is not certified for automotive use unless ordered with the SZ prefix. Designers targeting automotive applications must specify SZ1.5SMC91AT3G to ensure compliance with stress-test requirements and documentation traceability mandated by OEMs.
What is the working peak reverse voltage (VRWM) of the 1.5SMC91AT3G, and why does it matter?
The 1.5SMC91AT3G has a working peak reverse voltage (VRWM) of 77.8 V - the maximum continuous DC or peak AC voltage it can block while maintaining leakage current below 5 µA. This parameter is critical for proper selection: VRWM must be ≥ the normal operating voltage of the protected line to prevent false triggering, yet low enough to ensure timely clamping during overvoltage events. For a 48 V system, 77.8 V VRWM provides appropriate margin while enabling effective surge response.
Can the 1.5SMC91AT3G be used in UL 497B-compliant isolated loop circuits?
Yes, the entire 1.5SMC6.8AT3G series - including the 1.5SMC91AT3G - holds UL 497B recognition (File #E210057, Category QVGQ2) for isolated loop circuit protection. This certification covers performance in strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge testing - validating its suitability in safety-isolated applications such as medical equipment interfaces and telecom line cards where galvanic separation is required. No additional system-level certification is needed when using the 1.5SMC91AT3G per its specified mounting and layout guidelines.
1.5SMC91AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 77.8V
- Voltage - Breakdown (Min):
- 86.5V
- Voltage - Clamping (Max) @ Ipp:
- 125V
- Current - Peak Pulse (10/1000µs):
- 12A
- 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
1.5SMC91AT3G FAQ
1.How can I place an order for 1.5SMC91AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1.5SMC91AT3G 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 1.5SMC91AT3G reliable?
The price and inventory of 1.5SMC91AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1.5SMC91AT3G is usually 5 days.
3.What payment methods are accepted for 1.5SMC91AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1.5SMC91AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1.5SMC91AT3G?
1.5SMC91AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1.5SMC91AT3G 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 1.5SMC91AT3G?
For technical support, including 1.5SMC91AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1.5SMC91AT3G requirements.
6.How does Aetrix verify that 1.5SMC91AT3G is sourced from the original manufacturer or authorized distributors?
All 1.5SMC91AT3G 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 1.5SMC91AT3G meets industry standards.
7.What is the process for return or replacement of 1.5SMC91AT3G?
All 1.5SMC91AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1.5SMC91AT3G, 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 1.5SMC91AT3G part is unused and in its original packaging.
Return procedure for 1.5SMC91AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1.5SMC91AT3G Tags
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onsemi
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