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onsemi SZ1SMA20AT3G
- Part No.:
- SZ1SMA20AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- -
- Datasheet:
-
SZ1SMA20AT3G.pdf
- Description:
- TRANS VOLTAGE SUPPRESSOR DIODE,
- Quantity:
- Payment:
- Shipping:
Inventory:15,000
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Product details
Overview
SZ1SMA20AT3G from ON Semiconductor is a unidirectional 400 W peak power Zener transient voltage suppressor (TVS) in SMA package, with 20 V working peak reverse voltage (VRWM), 23.35 V nominal breakdown voltage (VBR), 32.4 V clamping voltage (VC) at 12.3 A peak pulse current (IPP), and <1 ns response time. It protects automotive power supplies and industrial control circuits against ESD and lightning-induced surges.
For engineers reviewing the SZ1SMA20AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, VC margin relative to IC absolute maximum ratings, IPP capability under IEC 61000-4-5 waveform, and AEC-Q101 qualification for automotive deployment.
Technical Context
This device operates as a unidirectional clamping TVS diode-conducting only during reverse overvoltage events above VBR while remaining high-impedance under normal bias. Its low zener impedance and fast sub-nanosecond response enable effective suppression of ESD (IEC 61000-4-2, >16 kV HBM) and surge transients (10/1000 µs waveform).
The SMA package supports top-slide or bottom-mount PCB assembly, features flat handling surface for pick-and-place accuracy, and meets Pb-free requirements with 260°C reflow tolerance. Thermal resistance from junction to ambient is 250°C/W at TA = 25°C, derating linearly above that temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 20 V - Maximum continuous reverse operating voltage before clamping begins; must exceed circuit's DC or peak AC rail voltage. |
| VBR @ IT=1 A | 22.2–24.5 V - Breakdown range defining turn-on threshold; ensures reliable conduction above system overvoltage threshold. |
| VC @ IPP=12.3 A | 32.4 V - Clamped voltage during 10/1000 µs surge; determines maximum stress on downstream ICs. |
| PPK | 400 W - Peak pulse power handling for 1 ms non-repetitive surge; validates robustness against IEC 61000-4-5 Level 4 events. |
| Response Time | <1 ns - Enables suppression before sensitive logic or analog circuitry sustains damage from fast-rising transients. |
| ESD Rating | Class 3 (>16 kV HBM) - Confirms suitability for environments with high electrostatic discharge risk without external protection layers. |
Pinout & Package
The SZ1SMA20AT3G is housed in an SMA (DO-214AC) surface-mount package per Case 403D, with cathode indicated by a molded polarity band. Dimensions: 4.57 mm × 2.60 mm × 2.20 mm (L × W × H), 0.160″ × 0.102″ × 0.087″.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked side) | Transient current sink node | Connected to protected line; conducts surge current to ground when reverse voltage exceeds VBR. |
| Anode | Reference/return path | Typically tied to system ground; completes clamping path during overvoltage event. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive powertrain and body electronics applications requiring zero-defect reliability and PPAP compliance. |
| Low profile SMA package | Enables high-density PCB layouts in space-constrained modules such as ECUs and motor controllers. |
| Flat handling surface | Ensures consistent placement accuracy during automated SMT assembly, reducing tombstoning and misalignment risk. |
| Pb-free construction | Meets RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow standards without compromising thermal performance. |
Applications
| Automotive Power Supply Protection | Industrial PLC Input Protection |
|---|---|
Use Scenario: Protecting 12 V battery-fed microcontroller power rails in engine control units against load dump and jump-start transients. IC Role / Device Role / Timing Role: Unidirectional clamping TVS placed between VIN and GND, absorbing energy before it reaches LDOs or MCU VDD pins. Use Value: Limits clamped voltage to 32.4 V, well below typical 36 V absolute maximum rating of automotive-grade regulators, preventing latch-up or permanent damage. | Use Scenario: Safeguarding 24 V digital input channels in programmable logic controllers exposed to field wiring inductive kickback. IC Role / Device Role / Timing Role: Reverse-biased transient suppressor across input terminals, shunting surge current away from optocoupler or Schmitt trigger inputs. Use Value: With 12.3 A IPP and 400 W PPK, it withstands repeated 10/1000 µs surges up to IEC 61000-4-5 Level 3 without degradation. |
| Medical Equipment ESD Shielding | Telecom Line Interface Protection |
Use Scenario: Guarding USB and serial communication ports on diagnostic imaging devices against hospital-grade ESD events. IC Role / Device Role / Timing Role: Board-level ESD suppressor on data lines, placed adjacent to connectors to minimize trace inductance. Use Value: Class 3 HBM rating (>16 kV) ensures immunity to operator-handling discharges without requiring additional TVS arrays or ferrites. | Use Scenario: Front-end protection for Ethernet PHY interfaces in network switches subjected to induced surges from nearby AC mains. IC Role / Device Role / Timing Role: Primary clamping element on isolated DC bias lines feeding PoE injectors or magnetics. Use Value: 32.4 V VC provides sufficient margin above 24 V PoE midspan bias while maintaining compatibility with IEEE 802.3af voltage limits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ20A | Higher PPK (600 W), larger SMB package (4.58 × 3.94 mm), same VRWM and VC. | Better suited for higher-energy surges but requires more PCB area; not drop-in compatible due to footprint mismatch. | Select SMBJ20A when surge energy exceeds 400 W and board space allows larger package. |
| 1.5SMC20A | Same VRWM and VC, but higher PPK (1500 W) in larger SMC package (7.11 × 6.22 mm); slower thermal recovery. | Used in high-power industrial drives where sustained surge repetition occurs; incompatible with SMA land pattern. | Choose 1.5SMC20A only when system-level testing confirms need for >1 kW surge handling and layout permits SMC footprint. |
Compared with SMBJ20A and 1.5SMC20A, SZ1SMA20AT3G offers optimal balance of 400 W surge capability, AEC-Q101 qualification, and compact SMA footprint-making it preferred for automotive and space-constrained industrial designs where exact VRWM match and proven field reliability are critical.
Availability
SZ1SMA20AT3G is available at Aetrix Electronics and suitable for automotive ECUs, industrial PLCs, medical diagnostics equipment, and telecom infrastructure requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for SZ1SMA20AT3G 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.
SZ1SMA20AT3G belongs to the SZ1SMAxxAT3G series of AEC-Q101-qualified unidirectional TVS diodes designed specifically for robust overvoltage protection in harsh automotive and industrial environments.
FAQ
What is the clamping voltage of SZ1SMA20AT3G and why does it matter?
The clamping voltage (VC) of SZ1SMA20AT3G is 32.4 V at 12.3 A peak pulse current. This value defines the maximum voltage imposed on protected circuitry during a transient event. For reliable system design, VC must remain below the absolute maximum voltage rating of downstream components-such as microcontrollers or interface ICs-to prevent damage or malfunction. SZ1SMA20AT3G's 32.4 V VC provides safe margin for 24 V and 36 V automotive and industrial rails.
Is SZ1SMA20AT3G suitable for automotive applications?
Yes, SZ1SMA20AT3G is AEC-Q101 qualified and PPAP capable, making it suitable for automotive applications including engine control units, body electronics, and infotainment systems. Its robust 400 W peak power rating, 20 V VRWM, and <1 ns response time meet stringent OEM requirements for transient suppression in 12 V and 24 V vehicle electrical architectures. The "SZ" prefix explicitly denotes automotive-grade process control and traceability.
How does the SMA package of SZ1SMA20AT3G affect PCB layout?
The SMA (DO-214AC) package of SZ1SMA20AT3G measures 4.57 mm × 2.60 mm × 2.20 mm and uses a two-pad footprint with cathode polarity band. Its low profile and flat handling surface support precise automated placement and high-density routing. Designers must observe ON Semiconductor's recommended minimum footprint (Case 403D outline) to ensure thermal performance and solder joint integrity-especially critical for sustained surge duty cycles.
What is the difference between VRWM and VBR for SZ1SMA20AT3G?
For SZ1SMA20AT3G, VRWM (20 V) is the maximum continuous reverse voltage the device blocks without significant leakage, while VBR (22.2–24.5 V) is the voltage at which it begins avalanche conduction at 1 A test current. VRWM must be selected ≥ circuit's normal operating voltage to avoid false triggering; VBR defines the onset of clamping. The 2.2–4.5 V gap between VRWM and VBR ensures noise immunity while guaranteeing rapid turn-on during overvoltage events.
Can SZ1SMA20AT3G replace older 1SMA20AT3G parts?
Yes, SZ1SMA20AT3G is a direct functional replacement for 1SMA20AT3G with identical electrical specifications, package, and pinout. The "SZ" prefix indicates enhanced process controls, AEC-Q101 qualification, and PPAP capability-making it preferred for new automotive designs. Both share the same marking code "RV", VRWM (20 V), VBR (22.2–24.5 V), and VC (32.4 V). No PCB or schematic changes are required when upgrading to SZ1SMA20AT3G.
SZ1SMA20AT3G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- -
- Series:
- *
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- -
- Unidirectional Channels:
- -
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- -
- Voltage - Breakdown (Min):
- -
- Voltage - Clamping (Max) @ Ipp:
- -
- Current - Peak Pulse (10/1000µs):
- -
- Power - Peak Pulse:
- -
- Power Line Protection:
- -
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
SZ1SMA20AT3G FAQ
1.How can I place an order for SZ1SMA20AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for SZ1SMA20AT3G 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 SZ1SMA20AT3G reliable?
The price and inventory of SZ1SMA20AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SZ1SMA20AT3G is usually 5 days.
3.What payment methods are accepted for SZ1SMA20AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SZ1SMA20AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SZ1SMA20AT3G?
SZ1SMA20AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SZ1SMA20AT3G 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 SZ1SMA20AT3G?
For technical support, including SZ1SMA20AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SZ1SMA20AT3G requirements.
6.How does Aetrix verify that SZ1SMA20AT3G is sourced from the original manufacturer or authorized distributors?
All SZ1SMA20AT3G 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 SZ1SMA20AT3G meets industry standards.
7.What is the process for return or replacement of SZ1SMA20AT3G?
All SZ1SMA20AT3G units undergo pre-shipment inspection (PSI). If there is an issue with SZ1SMA20AT3G, 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 SZ1SMA20AT3G part is unused and in its original packaging.
Return procedure for SZ1SMA20AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
SZ1SMA20AT3G Tags
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onsemi
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D12V0L1B2LP-7B
Diodes Incorporated
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