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onsemi 1.5SMC20AT3
- Part No.:
- 1.5SMC20AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
1.5SMC20AT3.pdf
- Description:
- TVS DIODE 17.1VWM 27.7VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:7,932
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Product details
Overview
1.5SMC20AT3 from ON Semiconductor is a unidirectional 1500 W peak power Zener transient voltage suppressor (TVS) designed for parallel clamping protection of DC power rails and signal lines. It features a 17.1 V working peak reverse voltage (VRWM), 20 V breakdown voltage (VBR) at 1 mA test current, 27.7 V maximum clamping voltage at 54 A peak pulse current, and <5 µA leakage above VRWM - used in automotive power supply input stages, industrial PLC I/O modules, and medical equipment surge protection circuits.
For engineers reviewing the 1.5SMC20AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include clamping voltage margin relative to protected IC VDD, peak pulse current handling under IEC 61000-4-5 surge conditions, UL 497B recognition for isolated loop protection, and SMC package thermal performance on FR-4 PCBs.
Technical Context
The 1.5SMC20AT3 operates as a unidirectional Zener-based TVS diode, conducting only during positive transients applied to its cathode. Its clamping action begins within <1 ns of overvoltage onset, with dynamic impedance low enough to limit overshoot when mounted close to sensitive circuitry using short PCB traces.
It is rated for non-repetitive 1 ms pulses up to 1500 W, derates linearly above 75°C junction temperature (RJL = 18.3°C/W), and meets UL 497B Class 3 ESD rating (>16 kV HBM). The device is not intended for bidirectional suppression or AC line applications without external series blocking components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Pulse Power | 1500 W @ 1 ms - sustains single high-energy surges per IEC 61000-4-5 Level 4 without failure |
| Working Peak Reverse Voltage (VRWM) | 17.1 V - maximum continuous DC or peak AC voltage the device blocks before clamping |
| Breakdown Voltage (VBR) | 20 V @ 1 mA - precise Zener conduction threshold enabling predictable turn-on margin above system rail |
| Clamping Voltage (VC) | 27.7 V @ 54 A - maximum voltage seen by protected load during worst-case surge event |
| Leakage Current (IR) | <5 µA @ 17.1 V - negligible standby power loss and minimal impact on high-impedance sensing nodes |
| Response Time | <1 ns - ensures clamping initiates before most semiconductor damage thresholds are exceeded |
| ESD Rating | Class 3 (>16 kV HBM) - exceeds IEC 61000-4-2 Level 4 for robust board-level ESD immunity |
Pinout & Package
1.5SMC20AT3 is housed in an SMC (DO-214AB) surface-mount plastic package (Case 403), featuring a modified L-bend leadform for enhanced solder joint reliability and a molded cathode notch for polarity identification. Mounting position is unrestricted; maximum soldering temperature is 260°C for 10 seconds.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient return path / low-side reference | Connected to system ground or lowest potential node; carries full surge current during clamping |
| Cathode | Protected line connection / high-side clamp node | Connected to the line being protected (e.g., +12 V rail); voltage referenced to anode during conduction |
Key Features
| Feature | Design Value |
|---|---|
| UL 497B Recognition (QVGV2) | Validated for isolated loop circuit protection - enables use in telecom/data line interfaces without additional certification effort |
| Low Clamping Ratio (VC/VBR) | 1.385 - tight ratio ensures minimal overvoltage stress on downstream ICs during surge events |
| Thermal Resistance (Junction-to-Lead) | 18.3°C/W - supports high-power dissipation when mounted on copper pads per Case 403 footprint |
| Surmetic™ Package Reliability | Void-free transfer-molded construction - delivers long-term moisture resistance and mechanical stability in automotive/industrial environments |
Applications
| Automotive Body Control Module (BCM) Power Input | Industrial PLC Analog Input Protection |
|---|---|
Use Scenario: 12 V battery-supplied BCM exposed to load dump (ISO 7637-2 Pulse 5a) and jump-start transients. IC Role / Device Role: Primary clamping element across main power rail, placed upstream of DC-DC converters and microcontroller LDOs. Use Value: Limits transient voltage to ≤27.7 V, preventing latch-up or gate oxide rupture in 3.3 V/5 V logic powered from the same rail. |
Use Scenario: 4–20 mA current loop input subjected to field wiring ESD and inductive kickback from solenoid actuation. IC Role / Device Role: First-line protection at terminal block, shunting surge energy before it reaches precision op-amps and ADC front-ends. Use Value: Sub-1 ns response and 27.7 V clamping prevent ADC saturation and maintain measurement integrity during 4 kV contact discharge events. |
| Medical Patient Monitor Power Supply | Point-of-Sale Terminal USB Port Protection |
Use Scenario: AC/DC adapter output feeding isolated DC rails in Class II medical devices requiring 2×MOPP compliance. IC Role / Device Role: Secondary-side TVS on isolated 5 V/3.3 V outputs to meet IEC 60601-1 surge immunity requirements. Use Value: UL 497B recognition confirms suitability for protected secondary circuits, eliminating need for separate isolation barrier validation. |
Use Scenario: USB VBUS line in retail terminals exposed to frequent hot-plug ESD and cable-induced transients. IC Role / Device Role: Unidirectional clamping between VBUS and GND, coordinated with series impedance to limit current into USB PHY. Use Value: 1500 W peak power rating handles multiple 8 kV air discharge events without degradation, supporting >50,000 connect/disconnect cycles. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ20A | Lower peak power (600 W), SMB package (smaller footprint, higher RJA) | Not suitable for IEC 61000-4-5 Level 4; limited to lower-energy surges | Select when space-constrained layouts prioritize size over surge margin |
| 1.5KE20A | Through-hole DO-201 package, identical electrical specs but no UL 497B recognition | Requires rework for SMT production; lacks certified isolated-loop qualification | Select only for legacy through-hole designs where UL certification is not required |
Compared with SMBJ20A and 1.5KE20A, the 1.5SMC20AT3 uniquely combines SMT compatibility, 1500 W surge capacity, and UL 497B listing - making it the preferred choice for new industrial and medical designs requiring certified, high-power, surface-mount transient protection.
Availability
1.5SMC20AT3 is available at Aetrix Electronics and suitable for automotive electronics, industrial programmable logic controllers, and medical diagnostic equipment requiring stable component supply and long-term lifecycle support.
Supply support for 1.5SMC20AT3 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 connectivity solutions for automotive, industrial, and cloud power applications.
The 1.5SMC20AT3 belongs to the SMC-series transient voltage suppressors - engineered specifically for high-reliability, high-surge-capacity protection in harsh-environment electronics where UL recognition and repeatable clamping performance are mandatory.
FAQ
What is the clamping voltage of the 1.5SMC20AT3 at its rated peak pulse current?
The 1.5SMC20AT3 has a maximum clamping voltage (VC) of 27.7 V when subjected to its rated peak pulse current of 54 A (10/1000 µs waveform). This value is guaranteed per the ON Semiconductor datasheet and defines the upper voltage limit imposed on protected circuitry during worst-case surge events - critical for ensuring downstream ICs remain within absolute maximum ratings.
Is the 1.5SMC20AT3 suitable for bidirectional transient suppression?
No, the 1.5SMC20AT3 is a unidirectional TVS diode and conducts only when the cathode is driven positive relative to the anode. It cannot suppress negative-going transients on the protected line. For bidirectional protection, a dedicated bidirectional device such as the 1.5SMC20CA must be used - the "A" suffix in 1.5SMC20AT3 explicitly denotes unidirectional configuration.
Does the 1.5SMC20AT3 meet UL 497B requirements for isolated loop protection?
Yes, the entire 1.5SMC6.8AT3 series - including the 1.5SMC20AT3 - holds UL 497B recognition under file #116110 in the Protector category (QVGV2). This certification validates its use in isolated communication loops (e.g., RS-485, CAN bus interfaces) where galvanic separation and surge withstand are required by safety standards.
What is the thermal resistance from junction to ambient for the 1.5SMC20AT3?
The 1.5SMC20AT3 has a junction-to-ambient thermal resistance (RJA) of 165°C/W when mounted on an FR-4 PCB using ON Semiconductor's minimum recommended footprint (Case 403 outline). This value assumes standard JEDEC test conditions and drops significantly with added copper area - design guidance recommends ≥1 in² of 2 oz copper connected to both leads for optimal power handling.
Can the 1.5SMC20AT3 replace the 1.5SMC18AT3 in an existing design?
The 1.5SMC20AT3 can replace the 1.5SMC18AT3 only if the protected circuit's operating voltage margin allows a higher VRWM (17.1 V vs. 15.3 V) and clamping voltage (27.7 V vs. 25.2 V). While both share identical SMC packaging and pinout, the increased VBR shifts the clamping threshold upward - verify that downstream components tolerate the 2.5 V higher clamped voltage during surge events before substitution.
1.5SMC20AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 17.1V
- Voltage - Breakdown (Min):
- 19V
- Voltage - Clamping (Max) @ Ipp:
- 27.7V
- Current - Peak Pulse (10/1000µs):
- 54A
- Power - Peak Pulse:
- 1500W (1.5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC
1.5SMC20AT3 FAQ
1.How can I place an order for 1.5SMC20AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1.5SMC20AT3 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 1.5SMC20AT3 reliable?
The price and inventory of 1.5SMC20AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1.5SMC20AT3 is usually 5 days.
3.What payment methods are accepted for 1.5SMC20AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1.5SMC20AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1.5SMC20AT3?
1.5SMC20AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1.5SMC20AT3 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 1.5SMC20AT3?
For technical support, including 1.5SMC20AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1.5SMC20AT3 requirements.
6.How does Aetrix verify that 1.5SMC20AT3 is sourced from the original manufacturer or authorized distributors?
All 1.5SMC20AT3 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 1.5SMC20AT3 meets industry standards.
7.What is the process for return or replacement of 1.5SMC20AT3?
All 1.5SMC20AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1.5SMC20AT3, 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 1.5SMC20AT3 part is unused and in its original packaging.
Return procedure for 1.5SMC20AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1.5SMC20AT3 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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onsemi
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Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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onsemi
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Diodes Incorporated
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D12V0L1B2LP-7B
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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