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onsemi 1SMC8.5AT3G
- Part No.:
- 1SMC8.5AT3G
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
1SMC8.5AT3G.pdf
- Description:
- TVS DIODE 8.5VWM 14.4VC SMC
- Quantity:
- Payment:
- Shipping:
Inventory:5,350
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Product details
Overview
1SMC8.5AT3G from onsemi is a unidirectional 1500 W peak power Zener transient voltage suppressor (TVS) designed for parallel clamping protection of sensitive electronics against ESD, lightning-induced surges, and inductive switching transients. It features a 8.5 V working peak reverse voltage (VRWM), 14.4 V maximum clamping voltage at 104.2 A peak pulse current, and sub-1 ns response time. It is used in automotive power line protection, industrial PLC I/O modules, and AC/DC adapter input stages.
For engineers reviewing the 1SMC8.5AT3G datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM margin over operating voltage, VC vs. IPP performance under 8.3 ms surge, UL 497B certification for isolated loop circuits, and SMC package thermal derating above 75°C.
Technical Context
The 1SMC8.5AT3G operates as a Zener-based avalanche diode, entering conduction when reverse voltage exceeds its specified breakdown range (9.44–10.4 V at 1 A test current). Its clamping action limits transient energy by shunting surge current to ground while maintaining voltage below 14.4 V at rated 104.2 A.
It is optimized for non-repetitive 8.3 ms half-sine surges per IEC 61000-4-5, with thermal design governed by junction-to-lead resistance (54.6 °C/W) and 260°C soldering tolerance. The device exhibits <1 μA leakage at 8.5 V and meets Class 3 HBM ESD rating (>16 kV).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 8.5 V - Maximum continuous reverse operating voltage before clamping begins |
| VBR (min/typ/max) | 9.44 / 9.92 / 10.4 V @ 1 A - Ensures reliable turn-on within defined tolerance band |
| VC @ IPP | 14.4 V @ 104.2 A - Peak clamped voltage during 8.3 ms surge; defines protected circuit's max stress |
| PPK | 1500 W @ 1 ms - Surge energy handling capacity; validated per 10×1000 μs waveform |
| IR @ VRWM | 25 μA - Low leakage preserves system standby power integrity |
| Response Time | <1 ns - Enables suppression before fast-edge transients damage downstream ICs |
| UL Recognition | UL 497B (QVGQ2 File #E210057) - Certified for isolated loop telecom and industrial signal protection |
Pinout & Package
1SMC8.5AT3G uses the SMC (DO-214AB) surface-mount plastic package (Case 403), measuring 5.59–6.10 mm × 6.60–7.11 mm × 1.90–2.41 mm. Cathode is marked by a molded notch on the body.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current sink during reverse-biased clamping | Connected to protected line; carries full surge current to ground path |
| Cathode | Reference terminal for Zener breakdown | Connected to system ground or low-impedance return; polarity must match layout marking |
Key Features
| Feature | Design Value |
|---|---|
| 1500 W peak pulse power | Handles high-energy 8.3 ms surges without degradation-critical for automotive load-dump immunity |
| UL 497B certified | Validated for telecom loop protection including strike voltage, endurance, and dielectric withstand tests |
| ESD Class 3 (>16 kV HBM) | Withstands human-body model discharges without parametric shift or failure |
| Pb-free Surmetic package | RoHS-compliant thermoset molding with corrosion-resistant leads and 260°C solder compatibility |
| Low zener impedance | Minimizes voltage overshoot during fast transients-verified by dynamic impedance curves in datasheet Figure 4 |
Applications
| Automotive Power Line Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: Protecting 12 V battery-fed ECUs from ISO 7637-2 pulse 1 (inductive switch-off) and pulse 2a (load dump). IC Role / Device Role / Timing Role: Unidirectional TVS placed between power rail and chassis ground to clamp transients before they reach LDOs or microcontrollers. Use Value: Clamps to ≤14.4 V at 104.2 A, preventing overvoltage damage to 16 V-rated input stages while surviving repeated 1500 W surges. | Use Scenario: Shielding 24 V DC digital input channels in programmable logic controllers from field-wiring induced surges and ESD events. IC Role / Device Role / Timing Role: Parallel-connected TVS on each channel's input node, referenced to common ground, activated within <1 ns. Use Value: UL 497B recognition ensures compliance in safety-critical isolated loop designs; low leakage avoids false triggering in high-impedance sensing circuits. |
| AC/DC Adapter Input Stage | Medical Equipment Signal Isolation Barrier |
Use Scenario: Secondary-side transient suppression on 5–12 V DC outputs of wall adapters exposed to mains-borne noise and coupling. IC Role / Device Role / Timing Role: Zener TVS across output rails to limit voltage excursions during capacitor discharge or transformer ringing. Use Value: 8.5 V VRWM provides ≥20% margin over nominal 6.8–10 V outputs; 14.4 V VC ensures downstream regulators remain within absolute max ratings. | Use Scenario: Protecting analog front-end inputs of patient-connected devices (e.g., ECG, pulse oximeters) where isolation barriers must survive defibrillation-level surges. IC Role / Device Role / Timing Role: TVS on isolated side of optocoupler or digital isolator, referenced to local ground, meeting IEC 60601-1 creepage/clearance requirements. Use Value: Pb-free Surmetic package supports medical RoHS compliance; UL 497B certification validates use in protected secondary circuits per clause 8.8.2. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ8.5A | Same VRWM (8.5 V) and VC (14.4 V), but lower PPK (600 W); SMB package (smaller footprint, higher RJA) | Limited to lower-energy surges (e.g., IEC 61000-4-2 ESD only); unsuitable for IEC 61000-4-5 line surges | Select 1SMC8.5AT3G when 1500 W surge capability and UL 497B certification are required. |
| 1.5SMC8.5A | Identical electrical specs and SMC package, but obsolete ON Semiconductor part number (replaced by 1SMC8.5AT3G) | No functional difference; same PCB layout, thermal profile, and qualification status | 1SMC8.5AT3G is the current production Pb-free version; direct replacement with identical form, fit, and function. |
Compared with SMBJ8.5A, the 1SMC8.5AT3G delivers triple the surge power handling and UL-certified reliability for industrial loops; versus 1.5SMC8.5A, it offers updated Pb-free compliance and active lifecycle support without design change.
Availability
1SMC8.5AT3G is available at Aetrix Electronics and suitable for automotive electronics, industrial control systems, and medical power supply designs requiring stable component supply, long-term lifecycle assurance, and UL-recognized surge protection.
Supply support for 1SMC8.5AT3G 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and medical markets.
The 1SMC8.5AT3G belongs to the SMC-series Zener TVS family, engineered for high-reliability transient suppression in harsh environments where robustness, certification, and repeatable clamping performance are mandatory.
FAQ
What is the clamping voltage of the 1SMC8.5AT3G at its rated peak pulse current?
The 1SMC8.5AT3G has a maximum clamping voltage (VC) of 14.4 V at its rated peak pulse current (IPP) of 104.2 A, measured under the standard 8.3 ms half-sine waveform. This value is guaranteed across temperature and ensures protected circuits remain below critical overvoltage thresholds during surge events. The 1SMC8.5AT3G achieves this with low dynamic impedance and minimal overshoot due to its sub-1 ns response.
Is the 1SMC8.5AT3G suitable for bidirectional transient protection?
No, the 1SMC8.5AT3G is a unidirectional TVS diode and is not rated for bidirectional operation. Its electrical characteristics-including breakdown voltage, clamping behavior, and leakage-are specified only for reverse-bias conduction. For AC line or bidirectional signal protection, a dedicated bidirectional part such as 1SMC8.5CAT3G must be selected. The 1SMC8.5AT3G datasheet explicitly states "Bidirectional devices will not be available in this series."
Does the 1SMC8.5AT3G meet UL 497B certification, and what does that cover?
Yes, the 1SMC8.5AT3G is UL 497B recognized (File #E210057, Category QVGQ2) for protector applications in isolated loop circuits. This certification covers validation of strike voltage breakdown, endurance conditioning, temperature stability, dielectric voltage-withstand, and discharge performance-going beyond basic flammability testing. It confirms suitability for telecom, industrial control, and medical signal isolation where regulatory compliance is mandatory.
What is the thermal resistance and derating behavior of the 1SMC8.5AT3G?
The 1SMC8.5AT3G has a junction-to-lead thermal resistance (RJL) of 54.6 °C/W and junction-to-ambient (RJA) of 165 °C/W. Its DC power dissipation derates linearly above 75°C at 18.3 mW/°C, and ambient-temperature derating begins at 25°C (6.1 mW/°C). These values are measured on FR-4 board with ON Semiconductor's recommended SMC footprint (Case 403), and must be applied in thermal layout planning to avoid junction overheating during sustained surge duty cycles.
How does the 1SMC8.5AT3G differ from the older 1.5SMC8.5A part?
The 1SMC8.5AT3G replaces the obsolete 1.5SMC8.5A with identical electrical specifications, mechanical dimensions, and SMC package outline. The primary differences are Pb-free compliance (indicated by the 'G' suffix), updated manufacturing process controls, and active product lifecycle status. No PCB layout or schematic changes are needed-the 1SMC8.5AT3G is a drop-in replacement with enhanced environmental compliance and continued supply assurance.
1SMC8.5AT3G 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):
- 8.5V
- Voltage - Breakdown (Min):
- 9.44V
- Voltage - Clamping (Max) @ Ipp:
- 14.4V
- Current - Peak Pulse (10/1000µs):
- 104.2A
- 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
1SMC8.5AT3G FAQ
1.How can I place an order for 1SMC8.5AT3G through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMC8.5AT3G 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 1SMC8.5AT3G reliable?
The price and inventory of 1SMC8.5AT3G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMC8.5AT3G is usually 5 days.
3.What payment methods are accepted for 1SMC8.5AT3G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMC8.5AT3G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMC8.5AT3G?
1SMC8.5AT3G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMC8.5AT3G 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 1SMC8.5AT3G?
For technical support, including 1SMC8.5AT3G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMC8.5AT3G requirements.
6.How does Aetrix verify that 1SMC8.5AT3G is sourced from the original manufacturer or authorized distributors?
All 1SMC8.5AT3G 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 1SMC8.5AT3G meets industry standards.
7.What is the process for return or replacement of 1SMC8.5AT3G?
All 1SMC8.5AT3G units undergo pre-shipment inspection (PSI). If there is an issue with 1SMC8.5AT3G, 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 1SMC8.5AT3G part is unused and in its original packaging.
Return procedure for 1SMC8.5AT3G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMC8.5AT3G Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
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D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
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D5V0L1B2WS-7
Diodes Incorporated
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