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onsemi 1SMA24AT3
- Part No.:
- 1SMA24AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA24AT3.pdf
- Description:
- TVS DIODE 24VWM 38.9VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:9,245
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Product details
Overview
1SMA24AT3 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 24 V working peak reverse voltage (VRWM), 28.1 V nominal breakdown voltage (VBR) at 1 A test current, 38.9 A maximum peak pulse current (IPP), and clamps to 38.9 V at that current - used in automotive power supply protection and industrial I/O interface surge suppression.
For engineers reviewing the 1SMA24AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, VC ≤ protected IC's absolute maximum rating, fast <1 ns response time, and SMA package compatibility with automated SMT assembly on FR-4 PCBs.
Technical Context
The 1SMA24AT3 operates as a unidirectional avalanche diode, conducting only during reverse overvoltage events above its VBR threshold while presenting low dynamic impedance (<1 Ω typical) during clamping. Its 400 W peak power rating applies to a 10/1000 µs waveform per R.E.A., with thermal derating starting at 75°C junction temperature.
It exhibits 2.5 µA maximum reverse leakage (IR) at 24 V VRWM, 3.5 V max forward voltage at 30 A IF, and ESD robustness >16 kV HBM - enabling use in environments with electrostatic discharge and lightning-induced surges without external series impedance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 24 V - minimum reverse standoff voltage before significant conduction; must exceed circuit's normal operating voltage. |
| VBR (min/typ/max) | 26.7 / 28.1 / 29.5 V @ 1 A - defines precise clamping onset; ensures predictable turn-on across temperature and unit variation. |
| VC @ IPP | 38.9 V @ 38.9 A - maximum clamped voltage during 400 W transient; determines whether downstream ICs remain within safe operating area. |
| PPK | 400 W @ 1 ms - peak surge energy handling capacity for non-repetitive transients like EFT or ISO 7637-2 pulses. |
| Response Time | <1 ns - enables protection of high-speed logic and microcontrollers against nanosecond-scale voltage spikes. |
| ESD Rating | Class 3 (>16 kV HBM) - qualifies for direct handling in uncontrolled environments without additional ESD mitigation. |
Pinout & Package
The 1SMA24AT3 is housed in an SMA (DO-214AC) surface-mount plastic package (Case 403D-02), measuring 4.06–4.57 mm × 2.29–2.92 mm × 1.91–2.41 mm, with cathode indicated by a molded band.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal | Connected to lower-potential side (e.g., GND or return path); conducts during forward-biased operation or bidirectional variants (not applicable here). |
| Cathode | Reverse-biased clamping terminal | Connected to protected line (e.g., 24 V rail); avalanche breakdown initiates here during overvoltage events. |
Key Features
| Feature | Design Value |
|---|---|
| 400 W peak pulse power | Supports IEC 61000-4-5 Level 4 (4 kV/2 Ω) surge testing on 24 V systems without derating or parallel devices. |
| Low zener impedance | Ensures minimal voltage overshoot during fast transients, maintaining tight clamping window between VBR and VC. |
| Flat handling surface | Enables consistent pick-and-place accuracy in high-volume SMT lines using standard vacuum nozzles. |
| Pb-free (1SMA24AT3G) option | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile requirements without lead contamination risk. |
Applications
| Automotive Power Rail Protection | Industrial PLC Digital Input Protection |
|---|---|
Use Scenario: Suppressing load dump and jump-start transients on 24 V battery-fed ECUs in commercial vehicles. IC Role / Device Role / Timing Role: Unidirectional TVS placed between battery rail and regulator input to clamp spikes up to ±120 V. Use Value: Limits voltage to ≤38.9 V during 38.9 A surge, preventing damage to LDOs and MCU power domains rated for 40 V max. | Use Scenario: Protecting 24 VDC digital input channels in programmable logic controllers from field-wiring induced surges. IC Role / Device Role / Timing Role: Standoff device mounted at connector entry point to shunt induced common-mode noise and EFT bursts. Use Value: Withstands 400 W transients while maintaining <2.5 µA leakage at 24 V, avoiding false triggering of optocoupler-based input stages. |
| Medical Equipment Power Supply Clamp | Telecom Line Card Surge Suppression |
Use Scenario: Safeguarding isolated DC-DC converter outputs in diagnostic imaging subsystems against back-EMF and coupling events. IC Role / Device Role / Timing Role: Secondary-side TVS on regulated 24 V output to prevent overvoltage propagation to sensitive analog front-ends. Use Value: Fast <1 ns response ensures clamping occurs before 100 ns-duration transients reach ADC reference rails or sensor bias networks. | Use Scenario: Front-end protection for Ethernet PHY power supplies in outdoor base station line cards exposed to lightning-induced ground potential rise. IC Role / Device Role / Timing Role: Primary-level TVS on 24 V auxiliary supply feeding PoE controllers and management ASICs. Use Value: 38.9 V clamping voltage aligns with 40 V-rated MOSFETs and PMICs, eliminating need for cascaded protection stages. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ24A | Same VRWM (24 V), higher PPK = 600 W, larger SMB package (DO-214AA), 43.3 V VC @ 43.3 A | Higher surge margin but requires 20% more PCB area; better suited for 10/1000 µs surges exceeding 400 W | Select when system-level surge testing exceeds IEC 61000-4-5 Level 4 or when thermal margin is constrained. |
| 1.5SMC24A | Same VRWM (24 V), PPK = 1500 W, much larger SMC package (DO-214AB), 39.4 V VC @ 38.1 A | Lower clamping voltage tolerance (±0.5 V vs ±1.4 V), tighter VBR distribution, but incompatible with fine-pitch SMA footprints | Choose for legacy designs requiring higher reliability margin or where board space allows larger footprint. |
Compared with SMBJ24A and 1.5SMC24A, the 1SMA24AT3 offers optimal balance of 400 W surge capability, compact SMA footprint, and 38.9 V clamping - making it ideal for space-constrained 24 V industrial and automotive modules where PCB real estate and cost are critical.
Availability
1SMA24AT3 is available at Aetrix Electronics and suitable for automotive power rail protection, industrial PLC digital input protection, and medical equipment power supply clamp applications requiring stable component supply and full traceability.
Supply support for 1SMA24AT3 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, sensor, and connectivity solutions for automotive, industrial, cloud, and medical markets.
The 1SMA24AT3 belongs to the SMA-series unidirectional TVS family, engineered specifically for high-reliability transient suppression in 5–78 V DC systems where compact size, fast response, and repeatable clamping performance are essential.
FAQ
What is the maximum clamping voltage of the 1SMA24AT3 under surge conditions?
The 1SMA24AT3 clamps to a maximum of 38.9 V when subjected to its rated 38.9 A peak pulse current (IPP), corresponding to a 400 W transient per the 10/1000 µs waveform. This value is measured at TA = 25°C and represents the upper limit of voltage seen by downstream components during worst-case surge events - critical for verifying compatibility with 40 V-rated ICs in the protected circuit.
Is the 1SMA24AT3 suitable for bidirectional transient suppression?
No, the 1SMA24AT3 is strictly unidirectional and conducts only during reverse-biased overvoltage events. For bidirectional protection, ON Semiconductor specifies separate part numbers such as 1SMA24CAT3. Using the 1SMA24AT3 in AC-coupled or bipolar signal paths will not provide forward-voltage transient suppression and may fail catastrophically under positive-going surges.
What is the thermal resistance from junction to ambient for the 1SMA24AT3?
The 1SMA24AT3 has a thermal resistance from junction to ambient (RJA) of 250°C/W when mounted on an FR-4 board using ON Semiconductor's minimum recommended footprint. At TA = 25°C, this limits continuous power dissipation to 0.5 W; derating begins at 4.0 mW/°C above 25°C - a key constraint when estimating steady-state leakage heating in high-temperature enclosures.
Does the 1SMA24AT3 meet RoHS requirements?
Yes, the 1SMA24AT3G variant is explicitly designated Pb-free and complies with RoHS Directive 2011/65/EU. The standard 1SMA24AT3 is not RoHS-compliant due to lead content in solderable terminations; designers requiring compliance must specify the "G" suffix version and verify compatibility with their reflow profile and board finish.
How does the 1SMA24AT3 compare to the 1SMA24A variant?
The 1SMA24AT3 and 1SMA24A share identical electrical specifications including VRWM, VBR, and VC, but differ in packaging and marking: the "T3" suffix denotes tape-and-reel packaging (5000 units/reel) with standardized orientation for SMT placement, whereas "A" indicates bulk or alternate packaging formats. Both use the same SMA (DO-214AC) case and have identical thermal and surge performance.
1SMA24AT3 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):
- 24V
- Voltage - Breakdown (Min):
- 26.7V
- Voltage - Clamping (Max) @ Ipp:
- 38.9V
- Current - Peak Pulse (10/1000µs):
- 10.3A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 500pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA24AT3 FAQ
1.How can I place an order for 1SMA24AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA24AT3 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 1SMA24AT3 reliable?
The price and inventory of 1SMA24AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA24AT3 is usually 5 days.
3.What payment methods are accepted for 1SMA24AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA24AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA24AT3?
1SMA24AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA24AT3 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 1SMA24AT3?
For technical support, including 1SMA24AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA24AT3 requirements.
6.How does Aetrix verify that 1SMA24AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMA24AT3 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 1SMA24AT3 meets industry standards.
7.What is the process for return or replacement of 1SMA24AT3?
All 1SMA24AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA24AT3, 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 1SMA24AT3 part is unused and in its original packaging.
Return procedure for 1SMA24AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA24AT3 Tags
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