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onsemi 1SMB20CAT3G
- Part No.:
- 1SMB20CAT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB20CAT3G.pdf
- Description:
- TVS DIODE 20VWM 32.4VC 425TEPBGA
- Quantity:
- Payment:
- Shipping:
Inventory:51,162
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Product details
Overview
1SMB20CAT3G from ON Semiconductor is a bidirectional 600 W peak power Zener transient voltage suppressor (TVS) designed for parallel overvoltage protection of sensitive electronics. It features a 20 V working peak reverse voltage (VRWM), 24.5 A maximum peak pulse current (IPP), 32.4 V clamping voltage (VC) at IPP, and <1 ns response time. It is used in automotive power line protection, industrial power supplies, and communication interface surge suppression.
For engineers reviewing the 1SMB20CAT3G datasheet, pinout, applications, or equivalent options, this page delivers verified electrical specs, UL 497B-certified isolation loop protection capability, SMB package mechanical data, and validated alternative parts for robust ESD/surge design review.
Technical Context
The 1SMB20CAT3G operates as a bidirectional Zener-based TVS diode with symmetrical clamping behavior across both polarities. Its breakdown voltage (VBR) is 22.2–24.5 V at 1 mA test current, and it maintains low zener impedance to ensure stable clamping under fast transients.
It complies with AEC-Q101 for automotive use and meets UL 497B requirements for isolated loop circuit protection. Its 600 W peak power rating applies to 10/1000 µs waveform pulses, with thermal derating above 75°C junction temperature and full operation from −65°C to +150°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 20 V - Maximum continuous reverse operating voltage before clamping begins; sets minimum system DC bus or signal swing tolerance. |
| VBR @ IT=1 mA | 22.2–24.5 V - Zener breakdown threshold; defines onset of avalanche conduction during overvoltage events. |
| VC @ IPP=24.5 A | 32.4 V - Clamped voltage seen by protected circuit during 10/1000 µs surge; determines maximum stress on downstream ICs. |
| IPP | 24.5 A - Peak pulse current the device safely shunts without failure; defines surge energy handling per IEC 61000-4-5 Level 4. |
| Ctyp @ 0 V, 1 MHz | 425 pF - Junction capacitance affecting high-frequency signal integrity; critical for USB, RS-485, or CAN bus placement. |
| Response Time | <1 ns - Time from transient onset to clamping activation; ensures protection before logic-level ICs experience overstress. |
| ESD Rating (HBM) | >16 kV - Human Body Model robustness; qualifies for direct-handling environments without additional ESD staging. |
Pinout & Package
The 1SMB20CAT3G is housed in an SMB (DO-214AA) surface-mount plastic package (Case 403C), Pb-free, void-free transfer-molded thermoset construction with modified L-bend leads for enhanced pad adhesion. Polarity band is not marked due to bidirectional symmetry.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode / Anode | Bidirectional terminal pair | Identical terminals; no polarity marking required; connects across protected line and return (e.g., VBUS/GND or differential pair). |
Key Features
| Feature | Design Value |
|---|---|
| UL 497B Recognition | Qualified for isolated loop circuit protection-enables certified deployment in telecom, medical, and industrial safety-critical interfaces. |
| AEC-Q101 Qualified | Validated for automotive underhood and powertrain applications including 12 V/24 V battery line clamping and load dump suppression. |
| 600 W Peak Power | Withstands IEC 61000-4-5 4th-level surges (4 kV/2 Ω) without degradation when properly mounted on FR-4 with recommended footprint. |
| Low Leakage Current | <5 µA @ VRWM - Minimizes standby power loss in always-on systems such as automotive body control modules or IoT edge sensors. |
| Pb-Free & RoHS Compliant | Meets global environmental compliance mandates; compatible with standard SnPb and lead-free reflow profiles up to 260°C for 10 s. |
Applications
| Automotive Power Line Protection | Industrial AC/DC Power Supply Input |
|---|---|
|
Use Scenario: Suppressing load dump transients (up to 120 V, 100 ms) on 12 V vehicle battery rails feeding ECUs and infotainment systems. IC Role / Device Role / Timing Role: Bidirectional shunt clamp placed between battery rail and ground, activated within <1 ns to limit voltage to ≤32.4 V. Use Value: Prevents latch-up or permanent damage to microcontrollers and CAN transceivers rated for 36 V absolute maximum. |
Use Scenario: Protecting primary-side rectifier outputs and secondary-side DC bus lines in DIN-rail-mounted 24 V industrial PSUs against lightning-induced surges. IC Role / Device Role / Timing Role: Parallel-connected TVS absorbing 600 W transient energy while maintaining clamping below 32.4 V for 24 V-rated DC-DC controllers. Use Value: Eliminates need for series fusing or active crowbar circuits, reducing BOM count and improving MTBF in harsh factory environments. |
| RS-485/RS-422 Data Line Protection | Medical Isolated Signal Interface |
|
Use Scenario: Safeguarding half-duplex RS-485 transceivers in building automation networks exposed to EFT and surge coupling from adjacent AC wiring. IC Role / Device Role / Timing Role: Bidirectional clamp across differential pair (A/B) and ground, leveraging 425 pF capacitance to avoid signal rise-time degradation at ≤10 Mbps. Use Value: Maintains EMC immunity per IEC 61000-4-4 (EFT) and IEC 61000-4-5 (surge) without compromising data integrity or requiring external filtering. |
Use Scenario: Protecting isolated analog front-ends in patient-monitoring devices where signal paths cross reinforced insulation barriers per IEC 60601-1. IC Role / Device Role / Timing Role: UL 497B-recognized TVS placed on secondary side of isolated DC-DC converter output, ensuring certified surge withstand on sensor input lines. Use Value: Enables single-device compliance with creepage/clearance and transient immunity requirements for Class II medical equipment without redesigning isolation barriers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SZ1SMB20CAT3G | AEC-Q101 qualified with PPAP documentation support; identical electrical specs and SMB package. | Required for automotive OEM production programs needing traceable process validation and change control. | Select SZ1SMB20CAT3G when automotive PPAP submission or site-specific qualification is mandated. |
| SMCJ20CA | Higher 1500 W peak power rating; larger SMC (DO-214AB) package; 34.2 V VC @ 43.3 A IPP. | Better suited for higher-energy surges (e.g., IEC 61000-4-5 Level 5); requires larger PCB footprint and thermal relief. | Choose SMCJ20CA only if system-level testing confirms >600 W surge exposure and layout allows SMC package integration. |
Compared with 1SMB20CAT3G, SZ1SMB20CAT3G adds automotive process rigor without electrical trade-offs, while SMCJ20CA trades compact SMB size for higher surge margin-making 1SMB20CAT3G optimal for space-constrained, UL-497B–compliant, and cost-sensitive industrial designs.
Availability
1SMB20CAT3G is available at Aetrix Electronics and suitable for automotive power line protection, industrial AC/DC power supply input stages, and RS-485/RS-422 data line protection requiring stable component supply, long-term lifecycle assurance, and UL-certified surge performance.
Supply support for 1SMB20CAT3G 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 communications markets.
The 1SMB20CAT3G belongs to ON Semiconductor's SMB-series Zener TVS family, engineered specifically for high-reliability, bidirectional surge suppression in space-constrained surface-mount applications demanding UL 497B recognition and AEC-Q101 compliance.
FAQ
What is the clamping voltage of the 1SMB20CAT3G under peak surge conditions?
The 1SMB20CAT3G has a maximum clamping voltage (VC) of 32.4 V when subjected to its rated peak pulse current (IPP) of 24.5 A using the standard 10/1000 µs waveform. This value is measured at TA = 25°C and represents the upper voltage limit imposed on protected circuitry during transient events. The 1SMB20CAT3G maintains this clamping performance consistently across its operational temperature range.
Is the 1SMB20CAT3G suitable for automotive applications?
Yes, the 1SMB20CAT3G is suitable for non-safety-critical automotive applications, but for production automotive use, ON Semiconductor recommends the SZ1SMB20CAT3G variant, which is fully AEC-Q101 qualified and PPAP capable. The 1SMB20CAT3G shares identical electrical specifications and SMB packaging, but lacks the documented process controls required by Tier 1 suppliers. Both parts meet the same surge and thermal ratings.
Does the 1SMB20CAT3G have UL recognition?
Yes, the 1SMB20CAT3G is UL Recognized under file E210057 for protector classification per UL 497B, covering isolated loop circuit protection. This certification validates performance in strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge testing-going beyond basic flammability compliance. UL 497B recognition is explicitly confirmed in the official ON Semiconductor datasheet for the 1SMB20CAT3G.
What is the junction capacitance of the 1SMB20CAT3G, and how does it affect high-speed data lines?
The 1SMB20CAT3G exhibits a typical junction capacitance (Ctyp) of 425 pF at 0 V bias and 1 MHz. While this value is moderate for a 600 W TVS, it remains compatible with RS-485 and RS-422 interfaces operating up to 10 Mbps when placed close to connectors with minimized trace length. For USB 2.0 or CAN FD, lower-capacitance alternatives would be preferred-but the 1SMB20CAT3G remains viable for robust, cost-sensitive industrial serial links.
Can the 1SMB20CAT3G replace a unidirectional TVS in a DC power rail?
No-the 1SMB20CAT3G is strictly bidirectional and must not be substituted for unidirectional TVS diodes (e.g., 1SMB20AT3G) in DC-only applications where reverse polarity protection is unnecessary. Using the 1SMB20CAT3G on a DC rail introduces symmetric clamping that may interfere with normal negative-voltage transients or cause unintended conduction. Always match TVS polarity type-bidirectional for AC or floating signals, unidirectional for DC rails with defined ground reference.
1SMB20CAT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 20V
- Voltage - Breakdown (Min):
- 22.2V
- Voltage - Clamping (Max) @ Ipp:
- 32.4V
- Current - Peak Pulse (10/1000µs):
- 18.5A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 425pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB20CAT3G FAQ
1.How can I place an order for 1SMB20CAT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB20CAT3G 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 1SMB20CAT3G reliable?
The price and inventory of 1SMB20CAT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB20CAT3G is usually 5 days.
3.What payment methods are accepted for 1SMB20CAT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB20CAT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB20CAT3G?
1SMB20CAT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB20CAT3G 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 1SMB20CAT3G?
For technical support, including 1SMB20CAT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB20CAT3G requirements.
6.How does Aetrix verify that 1SMB20CAT3G is sourced from the original manufacturer or authorized distributors?
All 1SMB20CAT3G 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 1SMB20CAT3G meets industry standards.
7.What is the process for return or replacement of 1SMB20CAT3G?
All 1SMB20CAT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB20CAT3G, 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 1SMB20CAT3G part is unused and in its original packaging.
Return procedure for 1SMB20CAT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB20CAT3G 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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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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