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onsemi 1SMA24CAT3
- Part No.:
- 1SMA24CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA24CAT3.pdf
- Description:
- TVS DIODE 24VWM 38.9VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:4,798
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Product details
Overview
1SMA24CAT3 from ON Semiconductor is a bidirectional 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), 28.11 V nominal breakdown voltage (VBR), 38.9 V clamping voltage (VC) at 10.3 A peak pulse current, and <1 ns response time. It is used in automotive power supply protection and industrial control I/O interfaces.
For engineers reviewing the 1SMA24CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM margin over operating voltage, clamping voltage headroom relative to protected IC absolute maximum ratings, surge current capability under 10/1000 µs waveform, and junction capacitance (260 pF at 0 V) for high-speed signal line compatibility.
Technical Context
This device operates as a bidirectional avalanche diode, conducting symmetrically in both polarities once reverse voltage exceeds VBR. Its low zener impedance and fast <1 ns response enable effective suppression of ESD (Class 3 HBM >16 kV) and lightning-induced surges without affecting normal circuit operation.
The SMA package (Case 403D) provides thermal resistance of 250°C/W junction-to-ambient (RJA) and supports 400 W peak power dissipation for 1 ms non-repetitive pulses. It is rated for operation from −65°C to +150°C and qualified to AEC-Q101 for automotive use when marked with SZ prefix.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 24 V - Maximum continuous reverse operating voltage before clamping begins; must exceed system's max DC or peak AC voltage. |
| VBR @ IT=1.0 A | 26.7–29.51 V - Breakdown occurs within this range at 1 A test current; defines turn-on threshold tolerance. |
| VC @ IPP=10.3 A | 38.9 V - Clamped voltage during 10.3 A 10/1000 µs surge; determines max stress on downstream components. |
| PPK | 400 W - Peak pulse power handling for 1 ms, defining surge energy absorption capacity (≈0.4 J). |
| CJ @ 0 V, 1 MHz | 260 pF - Junction capacitance limits use in >10 Mbps data lines; suitable for RS-485, CAN, or 24 V sensor inputs. |
| ESD Rating | Class 3 (>16 kV HBM) - Confirmed robustness against human-body-model electrostatic discharge events. |
Pinout & Package
Package: SMA (Surface Mount Assembly), Case 403D - Low-profile, void-free molded plastic housing with flat mounting surface; dimensions: 4.06–4.57 mm length × 2.29–2.92 mm width × 1.97–2.20 mm height; RoHS-compliant, Pb-free.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal during forward conduction; reverse-biased terminal during clamping | Connected to lower-potential side of protected node (e.g., GND or return path); polarity notch does not indicate cathode. |
| Cathode | Current exit terminal during forward conduction; reverse-biased terminal during clamping | Connected to higher-potential side (e.g., VCC or signal line); bidirectional symmetry means either terminal serves as "input" depending on transient polarity. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Protects AC-coupled or floating signal paths (e.g., RS-485, CAN bus) without polarity constraints. |
| 400 W peak pulse power | Handles IEC 61000-4-5 Level 4 surges (4 kV, 2 Ω source) on 24 V industrial lines with margin. |
| 260 pF junction capacitance | Enables use on moderate-speed digital interfaces while maintaining signal integrity up to ~20 MHz bandwidth. |
| AEC-Q101 qualification (SZ variant) | Validated for automotive under-hood and body electronics where temperature cycling and long-term reliability are critical. |
Applications
| Industrial PLC I/O Protection | Automotive Body Control Module |
|---|---|
Use Scenario: 24 V DC input channels on programmable logic controllers exposed to inductive kickback and field wiring surges. IC Role / Device Role / Timing Role: Bidirectional TVS placed between signal line and chassis ground to clamp transients before they reach input buffer ICs. Use Value: Limits clamped voltage to 38.9 V, staying below 40 V absolute max rating of common 24 V-rated interface ICs like SN65HVD230. | Use Scenario: LIN bus or switched 12 V power lines in door modules subject to load dump and jump-start transients. IC Role / Device Role / Timing Role: Standoff protection device mounted at connector entry point to absorb energy before reaching MCU GPIO or LIN transceiver. Use Value: Withstands 400 W surges and maintains <1 ns response, preventing latch-up or damage during ISO 7637-2 Pulse 5a events. |
| Medical Equipment Power Rails | Point-of-Sale Terminal Interfaces |
Use Scenario: 24 V auxiliary power distribution in diagnostic imaging subsystems where EMI immunity and safety isolation are critical. IC Role / Device Role / Timing Role: Secondary overvoltage clamp after primary DC/DC converter, protecting isolated DC-DC feedback optocouplers and sense resistors. Use Value: 2.5 µA max leakage at 24 V ensures minimal impact on precision current sensing circuits upstream. | Use Scenario: USB-powered kiosk peripherals with exposed external ports vulnerable to ESD during customer interaction. IC Role / Device Role / Timing Role: Board-level ESD suppressor on VBUS and D+/D− lines, placed before USB controller PHY. Use Value: Class 3 HBM rating (>16 kV) meets IEC 61000-4-2 Level 4 requirements for public-access equipment. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMA24CAT3G | AEC-Q101 qualified; identical electrical specs; includes SZ prefix denoting automotive-grade traceability and PPAP support. | Required for automotive OEM BOMs; same footprint and performance but with enhanced process controls and lot traceability. | Select when automotive qualification, PPAP documentation, or extended temperature validation is mandatory. |
| 1SMA24AT3G | Unidirectional version; same VRWM (24 V), VBR (26.7–29.51 V), and VC (38.9 V), but conducts only in reverse direction. | Suitable only for DC-biased lines with known polarity (e.g., 24 V supply to microcontroller); cannot protect AC or floating signals. | Choose only if circuit topology guarantees unidirectional transients and polarity is fixed; otherwise, 1SMA24CAT3 remains preferred for general-purpose robustness. |
Compared with SZ1SMA24CAT3G, the 1SMA24CAT3 offers identical clamping performance and package but lacks automotive certification documentation; compared with 1SMA24AT3G, it adds bidirectional protection essential for signal integrity in differential or floating systems-making it the default choice unless cost or qualification constraints dictate otherwise.
Availability
1SMA24CAT3 is available at Aetrix Electronics and suitable for industrial PLC I/O protection, automotive body control modules, and medical equipment power rail stabilization requiring stable component supply across multi-year production cycles.
Supply support for 1SMA24CAT3 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 energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1SMAxxCAT3G series belongs to ON Semiconductor's SURMETIC® TVS portfolio, engineered specifically for high-reliability transient suppression in harsh environments-including automotive, factory automation, and medical systems where surge immunity and long-term stability are critical.
FAQ
What is the clamping voltage of the 1SMA24CAT3 under a standard 10/1000 µs surge?
The 1SMA24CAT3 has a maximum clamping voltage (VC) of 38.9 V when subjected to its rated peak pulse current (IPP) of 10.3 A under the standardized 10/1000 µs double-exponential surge waveform. This value is measured at TA = 25°C and defines the upper voltage limit imposed on protected circuitry during transient events.
Is the 1SMA24CAT3 suitable for protecting CAN bus lines?
Yes, the 1SMA24CAT3 is suitable for CAN bus protection due to its bidirectional operation, 260 pF junction capacitance (which preserves signal integrity up to ~2 Mbps), and 38.9 V clamping voltage compatible with ISO 11898-2 transceivers rated for 40 V common-mode range. It must be placed close to the connector with proper grounding to maintain EMC performance.
Does the 1SMA24CAT3 have automotive qualification?
The base 1SMA24CAT3 is not AEC-Q101 qualified; however, its automotive-grade variant SZ1SMA24CAT3G shares identical electrical and mechanical specifications and is fully AEC-Q101 qualified with PPAP capability. For automotive applications requiring formal qualification, SZ1SMA24CAT3G-not 1SMA24CAT3-is the compliant option.
What is the maximum reverse leakage current of the 1SMA24CAT3 at its working voltage?
The 1SMA24CAT3 exhibits a maximum reverse leakage current (IR) of 2.5 µA when biased at its working peak reverse voltage (VRWM) of 24 V and measured at TA = 25°C. This low leakage ensures minimal power loss and avoids interference with high-impedance sensing or reference circuits connected to the protected node.
How does the 1SMA24CAT3 differ from the unidirectional 1SMA24AT3G?
The 1SMA24CAT3 is bidirectional, providing symmetrical clamping for both positive and negative transients, while the 1SMA24AT3G is unidirectional and only clamps reverse-polarity surges. Their VRWM, VBR, VC, and package are identical, but the CAT3 version is required for AC-coupled, floating, or differential signal lines such as RS-485 or LIN bus, whereas the AT3G suits fixed-polarity DC rails.
1SMA24CAT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- 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:
- 260pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA24CAT3 FAQ
1.How can I place an order for 1SMA24CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA24CAT3 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 1SMA24CAT3 reliable?
The price and inventory of 1SMA24CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA24CAT3 is usually 5 days.
3.What payment methods are accepted for 1SMA24CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA24CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA24CAT3?
1SMA24CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA24CAT3 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 1SMA24CAT3?
For technical support, including 1SMA24CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA24CAT3 requirements.
6.How does Aetrix verify that 1SMA24CAT3 is sourced from the original manufacturer or authorized distributors?
All 1SMA24CAT3 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 1SMA24CAT3 meets industry standards.
7.What is the process for return or replacement of 1SMA24CAT3?
All 1SMA24CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA24CAT3, 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 1SMA24CAT3 part is unused and in its original packaging.
Return procedure for 1SMA24CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA24CAT3 Tags
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