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onsemi 1SMA40CAT3
- Part No.:
- 1SMA40CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA40CAT3.pdf
- Description:
- TVS DIODE 40VWM 64.5VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:9,178
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Product details
Overview
1SMA40CAT3 from ON Semiconductor is a bidirectional 400 W peak power Zener transient voltage suppressor (TVS) designed to protect sensitive electronics against ESD and high-energy surges. It features a 40 V working peak reverse voltage (VRWM), 64.5 V clamping voltage (VC) at 6.2 A peak pulse current, and sub-1 ns response time - deployed in power supplies, automotive ECUs, and industrial control systems.
For engineers reviewing the 1SMA40CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping performance under 10/1000 µs surge, junction capacitance (160 pF @ 0 V), AEC-Q101 qualification status, and SMA package thermal derating above 75°C.
Technical Context
This bidirectional TVS diode operates symmetrically across both polarities, enabling robust protection without polarity constraints in AC-coupled or floating signal paths. Its low zener impedance and fast <1 ns response ensure effective clamping before downstream ICs experience overstress.
The device uses a planar Zener structure in an epoxy-molded SURMETIC® SMA package (Case 403D), rated for 260°C soldering (10 s), with flat handling surface for precise pick-and-place placement and compatibility with top-slide or bottom-board mounting.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Power | 400 W @ 1 ms 10/1000 µs waveform - sustains single high-energy transients without failure |
| VRWM | 40 V - maximum continuous reverse operating voltage before clamping initiates |
| VC @ IPP | 64.5 V @ 6.2 A - clamped voltage during surge, defining worst-case stress on protected circuit |
| Junction Capacitance | 160 pF @ 0 V, 1 MHz - impacts high-frequency signal integrity in data lines or RF interfaces |
| ESD Rating | Class 3 (>16 kV HBM) - meets IEC 61000-4-2 Level 4 for system-level ESD immunity |
| Response Time | <1 ns - ensures clamping activation prior to damage threshold of most CMOS ICs |
| Operating Temp | −65°C to +150°C - supports under-hood automotive and industrial environments |
Pinout & Package
SMA package (Case 403D), surface-mount, bidirectional - two-terminal device with cathode polarity notch (non-functional for polarity identification; terminals are symmetrical).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current entry (during negative surge) | One side of symmetrical Zener junction; conducts when voltage exceeds −VBR |
| Cathode | Transient current entry (during positive surge) | Other side of symmetrical Zener junction; conducts when voltage exceeds +VBR |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC signals, differential buses, or ungrounded circuits without polarity concerns |
| Low-profile SURMETIC® package | Height ≤ 1.52 mm - fits space-constrained PCB layouts while maintaining 20°C/W junction-to-lead thermal resistance |
| AEC-Q101 qualified | Validated for automotive applications including engine control, body electronics, and ADAS sensor interfaces |
| Pb-free construction | Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 moisture sensitivity level (MSL) 1 |
Applications
| Automotive Power Distribution | Industrial PLC I/O Protection |
|---|---|
Use Scenario: Protecting 12 V battery-fed microcontroller inputs in vehicle door modules against load-dump and ISO 7637-2 pulses. IC Role / Device Role / Timing Role: Primary overvoltage clamp placed directly at connector interface before filtering network. Use Value: Clamps 64.5 V at 6.2 A, limiting stress on downstream 5 V LDO and MCU GPIO within safe SOA limits. | Use Scenario: Safeguarding 24 V digital input channels in programmable logic controllers exposed to field-wiring transients. IC Role / Device Role / Timing Role: First-line transient suppression ahead of optocoupler or Schmitt-trigger input stage. Use Value: Sub-1 ns response prevents false triggering; 400 W rating handles repetitive surges per IEC 61000-4-4. |
| Medical Equipment Power Rails | Telecom DC Power Feeds |
Use Scenario: Shielding isolated DC-DC converter outputs in patient-monitoring devices from ESD and coupling noise. IC Role / Device Role / Timing Role: Secondary-side TVS on regulated 3.3 V/5 V rails feeding analog front-end and ADC subsystems. Use Value: 160 pF capacitance avoids signal distortion on precision analog paths; Class 3 ESD rating covers handling events. | Use Scenario: Protecting PoE-powered Ethernet switch ports against lightning-induced surges on 48 V DC feed lines. IC Role / Device Role / Timing Role: Bulk transient absorber mounted at power entry point, upstream of DC-DC regulation. Use Value: 400 W peak power withstands 10/1000 µs surges up to 100 A; bidirectional operation accommodates polarity reversal in fault conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMA40CAT3G | AEC-Q101 qualified with PPAP capability; identical electrical specs and package | Required for automotive production programs needing certified change control and traceability | Select SZ1SMA40CAT3G when automotive OEM compliance documentation (e.g., PPAP Level 3) is mandatory |
| 1.5SMC40CA | Higher 1500 W peak power; larger SMC package (7.11 × 6.22 mm); 69.4 V clamping at 21.5 A | Suitable where higher surge margin is needed but board area allows larger footprint | Choose 1.5SMC40CA only if 1500 W rating is required and PCB layout accommodates SMC outline |
Compared with 1SMA40CAT3, SZ1SMA40CAT3G adds automotive-grade process controls without altering electrical behavior, while 1.5SMC40CA trades compactness for higher surge capacity - making 1SMA40CAT3 optimal for space-constrained 400 W protection where AEC-Q101 is not mandated.
Availability
1SMA40CAT3 is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial programmable logic controllers, and medical diagnostic equipment requiring stable component supply and long-term manufacturability.
Supply support for 1SMA40CAT3 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 energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The 1SMAxxCAT3G series belongs to onsemi's transient voltage suppressor portfolio, engineered specifically for cost-sensitive, high-reliability surge protection in harsh environments - balancing clamping performance, thermal robustness, and Pb-free manufacturability.
FAQ
What is the clamping voltage of the 1SMA40CAT3 under standard surge conditions?
The 1SMA40CAT3 exhibits a maximum clamping voltage (VC) of 64.5 V when subjected to its rated peak pulse current of 6.2 A, measured using the 10/1000 µs waveform defined by R.E.A. This value defines the upper voltage limit imposed on protected circuitry during transient events and is confirmed in the Electrical Characteristics table on page 3 of the official datasheet.
Is the 1SMA40CAT3 suitable for automotive applications?
The 1SMA40CAT3 is not AEC-Q101 qualified; however, its automotive-grade variant - the SZ1SMA40CAT3G - carries full AEC-Q101 certification and PPAP capability. For non-automotive industrial or medical use, 1SMA40CAT3 remains appropriate, but 1SMA40CAT3 must not be used in production vehicles unless explicitly approved by the OEM under exception protocols.
What does the "T3" suffix mean in 1SMA40CAT3?
The "T3" suffix in 1SMA40CAT3 indicates packaging on a 13-inch tape-and-reel carrier, containing 5,000 units per reel. This is a shipping and handling designation per onsemi's ordering nomenclature and does not affect electrical or thermal specifications of the 1SMA40CAT3 device itself.
How does the junction capacitance of 1SMA40CAT3 affect high-speed signal lines?
With a typical junction capacitance of 160 pF at 0 V bias and 1 MHz, the 1SMA40CAT3 introduces measurable loading on high-speed digital or RF traces. It is unsuitable for USB 2.0, HDMI, or Ethernet PHY lanes but appropriate for lower-bandwidth interfaces like RS-485, CAN, or 24 V sensor inputs where bandwidth requirements remain below ~10 MHz.
Can the 1SMA40CAT3 replace a unidirectional TVS diode in a circuit?
No - the 1SMA40CAT3 is strictly bidirectional and lacks polarity-dependent conduction. Replacing a unidirectional TVS (e.g., 1SMA40AT3) with 1SMA40CAT3 may cause unintended conduction during normal reverse-biased operation. Circuit topology must be verified for symmetrical voltage excursions before substituting 1SMA40CAT3 in place of unidirectional variants.
1SMA40CAT3 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):
- 40V
- Voltage - Breakdown (Min):
- 44.4V
- Voltage - Clamping (Max) @ Ipp:
- 64.5V
- Current - Peak Pulse (10/1000µs):
- 6.2A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 160pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA40CAT3 FAQ
1.How can I place an order for 1SMA40CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA40CAT3 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 1SMA40CAT3 reliable?
The price and inventory of 1SMA40CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA40CAT3 is usually 5 days.
3.What payment methods are accepted for 1SMA40CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA40CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA40CAT3?
1SMA40CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA40CAT3 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 1SMA40CAT3?
For technical support, including 1SMA40CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA40CAT3 requirements.
6.How does Aetrix verify that 1SMA40CAT3 is sourced from the original manufacturer or authorized distributors?
All 1SMA40CAT3 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 1SMA40CAT3 meets industry standards.
7.What is the process for return or replacement of 1SMA40CAT3?
All 1SMA40CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA40CAT3, 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 1SMA40CAT3 part is unused and in its original packaging.
Return procedure for 1SMA40CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA40CAT3 Tags
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onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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