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onsemi 1SMA9.0AT3
- Part No.:
- 1SMA9.0AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AC, SMA
- Datasheet:
-
1SMA9.0AT3.pdf
- Description:
- TVS DIODE 9VWM 15.4VC SMA
- Quantity:
- Payment:
- Shipping:
Inventory:3,798
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Product details
Overview
1SMA9.0AT3 from ON Semiconductor is a unidirectional 400 W peak power Zener transient voltage suppressor (TVS) designed for clamping overvoltage transients in DC power rails and signal lines. It features a 9.0 V working peak reverse voltage (VRWM), 10.55 V nominal breakdown voltage (VBR) at 1 mA test current, 15.4 V clamping voltage (VC) at 26.0 A peak pulse current, and sub-1 ns response time. It is used in automotive power supply protection and industrial control I/O interfaces.
For engineers reviewing the 1SMA9.0AT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, VC margin relative to IC absolute maximum ratings, surge current capability under 10/1000 µs waveform, and SMA package thermal performance on FR-4 PCBs.
Technical Context
The 1SMA9.0AT3 operates as a unidirectional avalanche diode, conducting only during reverse overvoltage events above its VBR threshold while remaining high-impedance under normal bias. Its low zener impedance and fast <1 ns response enable effective suppression of ESD and lightning-induced transients without affecting steady-state operation.
It is rated for 400 W peak pulse power (10/1000 µs waveform), 0.5 W DC power dissipation at 25°C ambient, and 1.5 W at 75°C lead temperature. Thermal resistance from junction to ambient is 250°C/W, and junction-to-lead is 20°C/W - confirming suitability for surface-mount placement with minimum copper pad area per Case 403D footprint.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 9.0 V - Maximum continuous reverse voltage before clamping begins; must be ≥ circuit's DC operating voltage. |
| VBR @ IT=1 mA | 10.0–11.1 V - Breakdown occurs within this range; defines turn-on threshold for transient suppression. |
| VC @ IPP=26.0 A | 15.4 V - Clamped voltage seen by protected circuit during full-rated 400 W surge; determines stress on downstream ICs. |
| PPK | 400 W - Peak power handling for non-repetitive 10/1000 µs transients; validates robustness against ESD and load dump. |
| Response Time | <1 ns - Enables suppression before sensitive logic or analog circuits experience overstress. |
| ESD Rating | Class 3 (>16 kV HBM) - Confirms immunity to human-body model electrostatic discharge events. |
| Package | SMA (Case 403D) - Standardized surface-mount plastic package with cathode band marking and 2.29–2.92 mm width. |
Pinout & Package
SMA package (Case 403D): surface-mount, unidirectional, cathode indicated by molded band. Dimensions: 4.06–4.57 mm length × 2.29–2.92 mm width × 1.91–2.41 mm height. Flat handling surface supports accurate pick-and-place; mountable in any orientation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / low-side reference | Connected to ground or lower-potential rail; completes current path during reverse transient clamp. |
| Cathode | Reverse-biased input / protected line connection | Connected to the line being protected (e.g., 9 V supply rail); avalanche conduction initiates here during overvoltage. |
Key Features
| Feature | Design Value |
|---|---|
| 400 W peak pulse power | Validated for 10/1000 µs waveform - handles automotive load dump and industrial surge events without failure. |
| Clamping voltage ≤15.4 V at 26 A | Ensures protected ICs with 16 V absolute max rating remain within safe operating limits during worst-case surge. |
| ESD rating >16 kV HBM | Meets IEC 61000-4-2 Level 4 requirements for system-level ESD immunity without external shielding. |
| SMA package with flat handling surface | Enables high-yield automated assembly and stable thermal coupling to PCB copper for sustained power dissipation. |
| Pb-free option (1SMA9.0AT3G) | Complies with RoHS Directive 2011/65/EU without compromising electrical or thermal performance. |
Applications
| Automotive Power Rail Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: Protecting 9 V battery-fed microcontroller power inputs in vehicle body control modules against load dump transients up to 40 V. IC Role / Device Role / Timing Role: Unidirectional TVS placed between VCC and GND, clamping surges before they reach MCU's internal LDO or core logic. Use Value: Limits voltage to ≤15.4 V during 26 A transients, preventing latch-up or gate oxide damage in 12 V–rated MCUs. |
Use Scenario: Shielding 24 V digital input channels in programmable logic controllers from field-wiring induced surges and inductive kickback. IC Role / Device Role / Timing Role: Standoff device mounted at connector entry point, shunting energy away from optocoupler input stages. Use Value: Sub-1 ns response ensures clamping occurs before optocoupler LED forward voltage exceeds 5 V, preserving isolation integrity. |
| Medical Equipment Power Supply Input | Telecom Line Interface Protection |
Use Scenario: Safeguarding auxiliary 9 V DC-DC converter inputs in portable ultrasound devices exposed to ESD during handling and docking. IC Role / Device Role / Timing Role: Primary overvoltage clamp on secondary-side SMPS output, coordinated with upstream fuse and common-mode choke. Use Value: 16 kV HBM rating eliminates need for additional ESD protection components, reducing BOM count and board space. |
Use Scenario: Protecting RS-485 transceiver VCC pins in base station remote units connected to long outdoor cables susceptible to lightning-induced surges. IC Role / Device Role / Timing Role: Secondary-stage TVS after gas discharge tube (GDT), providing low-clamp refinement for fast-rising edges. Use Value: 15.4 V VC ensures transceiver ICs (e.g., MAX13487) remain below their 16 V ABSMAX, avoiding permanent damage during multi-kA events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ9.0A (ON Semiconductor) | Same VRWM (9.0 V) and VBR range, but 600 W PPK in SMB package; 20% larger footprint and 30% higher thermal mass. | Better suited for higher-energy surges where 400 W is marginal; requires PCB layout revision due to larger case size. | Select when system-level surge testing exceeds IEC 61000-4-5 Level 4 (1 kV/2 Ω) and board space permits SMB mounting. |
| 1.5SMC9.0A (ON Semiconductor) | Same electrical specs but in larger SMC package (7.11 × 6.22 mm); 1500 W PPK rating and 40 A IPP at same VC. | Used in front-end AC/DC power supplies or high-power motor drives where energy absorption dominates over space constraints. | Choose when protecting 9 V auxiliary rails fed from unregulated sources with high stored energy, and thermal derating margins are critical. |
Compared with 1SMA9.0AT3, SMBJ9.0A offers higher surge capacity in a moderately larger package, while 1.5SMC9.0A delivers triple the peak power in a footprint unsuitable for dense signal-layer layouts - making 1SMA9.0AT3 optimal for space-constrained 9 V rail protection where 400 W suffices.
Availability
1SMA9.0AT3 is available at Aetrix Electronics and suitable for automotive electronics, industrial PLCs, and medical device power supply designs requiring stable component supply, RoHS compliance, and proven surge reliability across extended temperature ranges.
Supply support for 1SMA9.0AT3 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 power management, analog, sensors, and discrete devices for automotive, industrial, and cloud power applications.
The 1SMAxxAT3 series was developed to deliver cost-effective, high-reliability transient suppression in compact surface-mount packages for DC power rail and interface line protection across harsh environments.
FAQ
What is the maximum clamping voltage of the 1SMA9.0AT3 under full-rated surge conditions?
The 1SMA9.0AT3 exhibits a maximum clamping voltage (VC) of 15.4 V when subjected to its rated peak pulse current of 26.0 A (10/1000 µs waveform). This value is measured per standard test conditions defined in the ON Semiconductor datasheet and represents the upper limit of voltage imposed on the protected circuit during worst-case transient events.
Is the 1SMA9.0AT3 suitable for bidirectional signal line protection?
No, the 1SMA9.0AT3 is a unidirectional TVS diode and must not be used on AC or bidirectional signal lines. It conducts only during reverse overvoltage events. For bidirectional protection, ON Semiconductor specifies separate parts such as 1SMA10CAT3 through 1SMA78CAT3 - the "C" suffix denotes bidirectional construction.
What is the thermal resistance from junction to ambient for the 1SMA9.0AT3 in standard mounting?
The 1SMA9.0AT3 has a thermal resistance from junction to ambient (RJA) of 250°C/W when mounted on an FR-4 PCB using ON Semiconductor's minimum recommended footprint (Case 403D outline). This value assumes no added copper pour; adding thermal pads reduces RJA significantly and improves sustained power handling.
Does the 1SMA9.0AT3 meet RoHS requirements?
Yes - the 1SMA9.0AT3G variant is explicitly designated as Pb-free and RoHS-compliant per Directive 2011/65/EU. The standard 1SMA9.0AT3 may contain lead; always verify part marking and ordering code (G suffix) for compliance-critical applications.
How does the 1SMA9.0AT3 compare to the 1SMA8.5AT3 in terms of breakdown voltage tolerance?
The 1SMA9.0AT3 has a specified breakdown voltage range of 10.0–11.1 V at 1 mA test current, while the 1SMA8.5AT3 is rated 9.44–10.4 V. The 1SMA9.0AT3 provides tighter alignment with 9 V nominal systems where VRWM must exceed operating voltage without excessive margin that raises clamping voltage unnecessarily.
1SMA9.0AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AC, SMA
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 9V
- Voltage - Breakdown (Min):
- 10V
- Voltage - Clamping (Max) @ Ipp:
- 15.4V
- Current - Peak Pulse (10/1000µs):
- 26A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 1200pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMA
1SMA9.0AT3 FAQ
1.How can I place an order for 1SMA9.0AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMA9.0AT3 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 1SMA9.0AT3 reliable?
The price and inventory of 1SMA9.0AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMA9.0AT3 is usually 5 days.
3.What payment methods are accepted for 1SMA9.0AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMA9.0AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMA9.0AT3?
1SMA9.0AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMA9.0AT3 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 1SMA9.0AT3?
For technical support, including 1SMA9.0AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMA9.0AT3 requirements.
6.How does Aetrix verify that 1SMA9.0AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMA9.0AT3 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 1SMA9.0AT3 meets industry standards.
7.What is the process for return or replacement of 1SMA9.0AT3?
All 1SMA9.0AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMA9.0AT3, 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 1SMA9.0AT3 part is unused and in its original packaging.
Return procedure for 1SMA9.0AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMA9.0AT3 Tags
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ESD9B5.0ST5G
onsemi
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DESD3V3E1BL-7B
Diodes Incorporated
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ESD5Z3.3T1G
onsemi
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D5V0H1B2LP-7B
Diodes Incorporated
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D5V0P1B2LP-7B
Diodes Incorporated
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DESD5V0U1BA-7
Diodes Incorporated
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ESD5Z5.0T1G
onsemi
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DESD5V0U1BB-7
Diodes Incorporated
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D12V0L1B2LP-7B
Diodes Incorporated
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PESD2V0Y1BSFYL
Nexperia USA Inc.
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DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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