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onsemi 1SMA75AT3G
- Part No.:
- 1SMA75AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA75AT3G.pdf
- Description:
- TVS DIODE 75VWM 121VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:8,306
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Product details
Overview
1SMA75AT3G from ON Semiconductor is a unidirectional 400 W peak power Zener transient voltage suppressor (TVS) designed for clamping high-energy transients in DC power rails and signal lines. It features a 75 V working peak reverse voltage (VRWM), 83.3–92.1 V breakdown voltage (VBR) at 1 mA test current, 121 A maximum peak pulse current (IPP), and clamps to ≤121 V at IPP. It is used in automotive power supply protection and industrial control I/O interfaces.
For engineers reviewing the 1SMA75AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, VC ≤ protected circuit's absolute maximum rating, low zener impedance for fast clamping, sub-1 ns response time, and SMA package compatibility with automated SMT assembly.
Technical Context
The 1SMA75AT3G operates as a unidirectional avalanche diode, conducting only during negative transients relative to its anode–cathode polarity. Its clamping behavior is defined by the 10/1000 µs surge waveform per R.E.A., with thermal derating applied above 75°C junction temperature using RJL = 20 °C/W.
It exhibits <1 ns response time and ESD robustness >16 kV HBM, enabled by low-junction-capacitance design and optimized silicon geometry. The device is not bidirectional-bidirectional variants (e.g., 1SMA75CAT3) are separate part numbers and not functionally interchangeable.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Power Dissipation | 400 W @ 1 ms, 10/1000 µs waveform - sustains single high-energy surges without failure |
| Working Peak Reverse Voltage (VRWM) | 75 V - maximum continuous reverse voltage before significant leakage; sets minimum system operating margin |
| Breakdown Voltage (VBR) | 83.3–92.1 V @ IT = 1 mA - defines onset of avalanche conduction; tight tolerance enables predictable clamping threshold |
| Clamping Voltage (VC) | ≤121 V @ IPP = 121 A - maximum voltage seen by protected circuit during rated surge |
| Response Time | <1 ns - ensures suppression initiates before transient energy couples into sensitive downstream components |
| ESD Rating | Class 3 (>16 kV HBM) - withstands human-body-model electrostatic discharge events common in handling and assembly |
| Thermal Resistance (Junction-to-Lead) | 20 °C/W - supports 1.5 W steady-state dissipation at TL = 75°C with proper PCB copper area |
Pinout & Package
SMA package (Case 403D-02), surface-mount, low-profile plastic housing with molded cathode band marking. Flat handling surface enables precise pick-and-place placement. Mounting position is unrestricted; compatible with top-slide or bottom-board mounting.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current return path | Connected to lower-potential side (e.g., GND or return rail); conducts surge current during reverse-biased clamping |
| Cathode | Transient voltage reference node | Marked by band; connected to protected line (e.g., 24 V rail); clamps voltage to VC when transient exceeds VRWM |
Key Features
| Feature | Design Value |
|---|---|
| Unidirectional clamping architecture | Enables targeted protection of positive-rail transients without interfering with normal forward-biased operation |
| Surmetic™ molded plastic case | Void-free encapsulation ensures long-term reliability under thermal cycling and humidity exposure |
| Pb-free (RoHS-compliant) construction | Meets global environmental regulations; compatible with lead-free reflow profiles up to 260°C for 10 s |
| Low zener impedance | Minimizes voltage overshoot during fast-rising transients, improving protection fidelity for high-speed digital I/O |
| Flat handling surface | Reduces placement skew and tombstoning risk during high-speed SMT assembly |
Applications
| Automotive Power Distribution | Industrial PLC I/O Protection |
|---|---|
Use Scenario: Suppressing load-dump transients on 24 V battery-fed ECUs and body-control modules. IC Role / Device Role / Timing Role: Standoff TVS diode placed between power rail and ground, clamping surges within 1 ns to protect downstream regulators and microcontrollers. Use Value: Withstands 400 W peak pulses and maintains VRWM ≥ 24 V system nominal, preventing latch-up or burnout during ISO 7637-2 Pulse 5a events. |
Use Scenario: Protecting analog input channels (e.g., 4–20 mA sensors) from field-wiring induced surges in factory automation cabinets. IC Role / Device Role / Timing Role: Unidirectional shunt clamp on signal line, referenced to local ground, activated only during overvoltage faults. Use Value: Clamps to ≤121 V while limiting leakage to ≤2.5 µA at 75 V, preserving sensor accuracy during normal operation. |
| Medical Equipment Power Rails | Telecom DC Power Feeds |
Use Scenario: Safeguarding isolated DC–DC converter outputs in diagnostic imaging subsystems against ESD and switching noise. IC Role / Device Role / Timing Role: Secondary-side TVS on regulated 5 V or 12 V outputs, absorbing fast transients before they reach FPGA or ADC power pins. Use Value: Sub-1 ns response prevents voltage spikes from violating IC absolute maximum ratings; Pb-free compliance meets medical RoHS requirements. |
Use Scenario: Front-end surge protection on -48 V telecom power distribution boards in base station cabinets. IC Role / Device Role / Timing Role: Rail-to-ground clamp on primary DC input, sized to handle lightning-induced surges per IEC 61000-4-5 Level 4. Use Value: 400 W peak power rating and 121 A IPP support multi-kA surge currents typical in outdoor telecom installations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ75A | 600 W peak power, SMB package (larger footprint), VRWM = 75 V, VC = 121 V @ IPP = 167 A | Higher surge capacity but requires larger PCB area; better suited for higher-reliability telecom infrastructure | Select when system-level surge testing exceeds IEC 61000-4-5 Level 4 or when board space permits larger package |
| 1N6158A | 400 W peak power, DO-204AC (DO-15) through-hole package, VRWM = 75 V, VC = 121 V @ IPP = 121 A | Through-hole mounting only; no SMT compatibility; longer lead inductance reduces high-frequency effectiveness | Choose only for legacy through-hole designs or prototyping where reflow capability is unavailable |
Compared with SMBJ75A and 1N6158A, the 1SMA75AT3G offers optimal balance of 400 W surge capability, compact SMA footprint, and sub-1 ns response-making it preferred for space-constrained, high-density SMT designs requiring fast, reliable rail clamping.
Availability
1SMA75AT3G is available at Aetrix Electronics and suitable for automotive power distribution, industrial PLC I/O protection, and medical equipment power rails requiring stable component supply and RoHS-compliant sourcing.
Supply support for 1SMA75AT3G 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 power management, analog, sensing, and connectivity solutions for automotive, industrial, and cloud-power applications.
The 1SMAxxAT3G series belongs to onsemi's transient voltage suppressor product line, engineered specifically for robust, cost-effective overvoltage protection in high-volume SMT power and signal line applications.
FAQ
What is the maximum clamping voltage of the 1SMA75AT3G under rated surge conditions?
The 1SMA75AT3G clamps to a maximum of 121 V when subjected to its rated peak pulse current of 121 A, measured using the standard 10/1000 µs waveform. This value is guaranteed across the full operating temperature range and defines the upper voltage limit imposed on protected circuits during surge events. The 121 V clamping voltage directly constrains the stress on downstream components like DC–DC converters or microcontroller I/O pins.
Is the 1SMA75AT3G suitable for bidirectional transient suppression?
No, the 1SMA75AT3G is strictly unidirectional and conducts only when the cathode is driven positive relative to the anode. For bidirectional protection, onsemi specifies separate part numbers such as 1SMA75CAT3. Using the 1SMA75AT3G in a bidirectional configuration would leave the circuit unprotected during positive transients on the anode side, risking damage to connected devices.
What is the recommended PCB layout for optimal thermal performance of the 1SMA75AT3G?
For optimal thermal performance, the 1SMA75AT3G should be mounted on a minimum 1″ square copper pad on FR-4 board, per ON Semiconductor's recommended footprint in Case 403D-02. This layout achieves the specified thermal resistance of 20 °C/W (junction-to-lead) and supports 1.5 W steady-state dissipation at 75°C lead temperature. Avoid narrow traces or isolated pads that impede heat spreading.
Does the "G" suffix in 1SMA75AT3G indicate RoHS compliance?
Yes, the "G" suffix explicitly denotes a Pb-free (RoHS-compliant) version of the 1SMA75AT3G, manufactured using lead-free solder terminations and halogen-free molding compound. It is qualified for reflow soldering at peak temperatures up to 260°C for 10 seconds, meeting JEDEC J-STD-020 moisture sensitivity level 1 requirements.
How does the 1SMA75AT3G compare to the 1SMA75A variant without the "T3G" suffix?
The 1SMA75AT3G and legacy 1SMA75A share identical electrical specifications and SMA packaging, but the "T3G" suffix confirms tape-and-reel packaging (5000 units/reel) and Pb-free construction. The base 1SMA75A may be supplied in bulk or non-Pb-free form depending on date code and lot; 1SMA75AT3G guarantees both packaging format and RoHS compliance for automated SMT lines.
1SMA75AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AC, SMA
- 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):
- 3.3A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 180pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA75AT3G FAQ
1.How can I place an order for 1SMA75AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA75AT3G 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 1SMA75AT3G reliable?
The price and inventory of 1SMA75AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA75AT3G is usually 5 days.
3.What payment methods are accepted for 1SMA75AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA75AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA75AT3G?
1SMA75AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA75AT3G 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 1SMA75AT3G?
For technical support, including 1SMA75AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA75AT3G requirements.
6.How does Aetrix verify that 1SMA75AT3G is sourced from the original manufacturer or authorized distributors?
All 1SMA75AT3G 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 1SMA75AT3G meets industry standards.
7.What is the process for return or replacement of 1SMA75AT3G?
All 1SMA75AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA75AT3G, 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 1SMA75AT3G part is unused and in its original packaging.
Return procedure for 1SMA75AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA75AT3G Tags
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