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onsemi 1SMB170AT3
- Part No.:
- 1SMB170AT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB170AT3.pdf
- Description:
- TVS DIODE 170VWM 275VC SMB
- Quantity:
- Payment:
- Shipping:
Inventory:9,944
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Product details
Overview
1SMB170AT3 from ON Semiconductor is a unidirectional 600 W peak power TVS diode designed for transient overvoltage protection in DC power rails and signal lines. It features a 170 V working peak reverse voltage (VRWM), 209 V maximum clamping voltage (VC) at 2.2 A peak pulse current (IPP), and sub-1 ns response time. It is used in industrial power supplies, automotive ECUs, and telecom interface circuits to suppress ESD and lightning-induced surges.
For engineers reviewing the 1SMB170AT3 datasheet, pinout, applications, or equivalent options, this device serves as a high-energy, low-leakage transient suppressor with UL 497B recognition for isolated loop circuit protection and Pb-free SMB package compatibility with automated SMT assembly.
Technical Context
The 1SMB170AT3 operates as a Zener-based unidirectional TVS, leveraging avalanche breakdown to clamp transients above its VRWM of 170 V. Its 2.2 A IPP rating corresponds to a 600 W peak pulse power at 1 ms, validated per IEC 61000-4-5 waveform standards.
It exhibits 5.0 µA max reverse leakage at VRWM, 209 V clamping voltage under full surge, and 120 pF typical junction capacitance at 0 V bias - enabling effective suppression without signal integrity degradation in medium-speed interfaces.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Peak Power Dissipation | 600 W @ 1 ms pulse - sustains single high-energy surges common in industrial and automotive load-dump events |
| Working Peak Reverse Voltage (VRWM) | 170 V - sets minimum operating voltage threshold; must exceed system's continuous DC bus or signal swing |
| Clamping Voltage (VC) | 209 V @ IPP = 2.2 A - defines maximum voltage seen by protected circuit during worst-case transient |
| Breakdown Voltage (VBR) | 189–209 V @ IT = 1.0 mA - ensures reliable, repeatable avalanche conduction onset |
| Reverse Leakage Current | <5.0 µA @ 170 V - minimizes standby power loss and avoids false triggering in high-impedance nodes |
| Junction Capacitance | 120 pF @ 0 V, 1 MHz - low enough for <10 Mbps digital lines but unsuitable for >100 Mbps USB or Ethernet |
| ESD Rating | Class 3 (>16 kV HBM) - meets IEC 61000-4-2 Level 4 for robust board-level ESD immunity |
Pinout & Package
1SMB170AT3 is housed in the ON Semiconductor Surmetic™ SMB (Case 403A) surface-mount plastic package: void-free thermosetting body, modified L-bend leads, cathode indicated by polarity band, RoHS-compliant, rated for 260°C/10s soldering.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry during forward conduction; grounded or connected to low-impedance return path in unidirectional TVS configuration | Must be routed with minimal inductance to avoid clamping overshoot; ties directly to system ground plane |
| Cathode | Protected line connection point; carries transient current into anode during reverse avalanche | Connected to the line being safeguarded (e.g., 170 V DC rail or RS-485 A/B); polarity band identifies this terminal |
Key Features
| Feature | Design Value |
|---|---|
| 600 W peak pulse power | Enables protection against severe transients including ISO 7637-2 Pulse 5a (load dump) in 24 V automotive systems |
| UL 497B recognition | Validates suitability for primary-side isolation barrier protection in telecom and industrial loop-powered devices |
| Sub-1 ns response time | Ensures clamping activation before most semiconductor damage thresholds are exceeded in MOSFET gate or MCU I/O paths |
| Pb-free SMB package | Supports lead-free reflow profiles (J-STD-020) and eliminates RoHS non-compliance risk in global manufacturing |
| Low zener impedance | Maintains tight VC tolerance across production lots, critical for predictable overvoltage margin in safety-critical systems |
Applications
| Industrial Power Supply Protection | Automotive ECU Input Protection |
|---|---|
|
Use Scenario: 170 V DC intermediate bus in programmable logic controller (PLC) power module exposed to switching noise and inductive kickback. IC Role / Device Role / Timing Role: Unidirectional TVS placed between +170 V rail and chassis ground to clamp positive-going transients only. Use Value: Limits voltage excursion to ≤209 V during 600 W surges, preventing damage to downstream DC-DC controllers and FET drivers. |
Use Scenario: CAN transceiver power input in engine control unit subjected to ISO 7637-2 load dump pulses up to 120 V. IC Role / Device Role / Timing Role: Standoff protector on 24 V supply line upstream of LDO regulator, absorbing energy before regulation stage. Use Value: Withstands 2.2 A peak current at 1 ms, reducing stress on linear regulators and eliminating need for oversized input capacitors. |
| Telecom Isolated Loop Interface | Medical Equipment Signal Line Guarding |
|
Use Scenario: 48 V phantom-powered analog audio line in VoIP gateway requiring UL 497B-compliant surge protection. IC Role / Device Role / Timing Role: Primary protector on isolated secondary side of transformer-coupled interface, referenced to local ground. Use Value: UL 497B certification confirms compliance for use in Class 2 circuits, avoiding additional isolation barrier design overhead. |
Use Scenario: Analog sensor input (e.g., pressure transducer) in portable diagnostic device exposed to ESD during handling. IC Role / Device Role / Timing Role: Low-leakage (≤5 µA) TVS on signal path to preserve microvolt-level accuracy while shunting HBM discharges. Use Value: 120 pF capacitance avoids filtering of <10 kHz physiological signals; 16 kV HBM rating exceeds IEC 61000-4-2 Level 4 requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ170A | Same VRWM (170 V) and VC (209 V), but rated for 600 W @ 10/1000 µs waveform (vs. 1 ms for 1SMB170AT3); slightly higher IR (10 µA) | Optimized for shorter-duration transients (IEC 61000-4-5); less suitable for sustained 1 ms load-dump events | Select SMBJ170A when surge profile matches 10/1000 µs standard; verify thermal derating for repeated pulses. |
| 1.5SMC170A | Higher power rating (1500 W), DO-214AB package (larger footprint), same VRWM/VC specs; 10× higher junction capacitance (~1200 pF) | Used where higher single-pulse energy absorption is required, but incompatible with space-constrained layouts | Choose 1.5SMC170A only if PCB area allows larger case and system bandwidth tolerates >1 nF capacitance. |
Compared with SMBJ170A and 1.5SMC170A, the 1SMB170AT3 offers optimal balance of compact SMB footprint, 1 ms pulse capability, and low capacitance - making it preferred for space-limited industrial and automotive modules requiring precise clamping at 170 V nominal rails.
Availability
1SMB170AT3 is available at Aetrix Electronics and suitable for industrial power supplies, automotive electronic control units, and telecom interface circuits requiring stable component supply and long-term lifecycle support.
Supply support for 1SMB170AT3 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 energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and medical markets.
The 1SMB170AT3 belongs to the SMB series of unidirectional TVS diodes engineered for high-reliability transient suppression in harsh environments - emphasizing robust surge handling, UL certification, and manufacturability in high-volume SMT lines.
FAQ
What is the clamping voltage of the 1SMB170AT3 under maximum surge conditions?
The 1SMB170AT3 has a maximum clamping voltage (VC) of 209 V when subjected to its rated peak pulse current of 2.2 A (corresponding to 600 W at 1 ms). This value is measured per the 10 × 1000 µs waveform defined in the datasheet and represents the upper limit of voltage imposed on the protected circuit during a worst-case transient event. The 1SMB170AT3 maintains this clamping performance across its qualified temperature range of −65 °C to +150 °C.
Is the 1SMB170AT3 suitable for bidirectional signal line protection?
No, the 1SMB170AT3 is a unidirectional TVS diode and is not suitable for bidirectional signal line protection such as RS-485 or USB data lines. Its design clamps only positive transients relative to ground; negative excursions will forward-bias the device and cause conduction. For bidirectional protection, ON Semiconductor offers the 1SMB170CAT3 variant (not the 1SMB170AT3), which features symmetrical breakdown in both directions and is explicitly marked as bidirectional in the datasheet.
Does the 1SMB170AT3 meet UL 497B requirements for isolated loop protection?
Yes, the entire 1SMB5.0AT3 series - including the 1SMB170AT3 - holds UL 497B recognition under File #E210057 for protectors in isolated loop circuits. This certification covers testing for strike voltage breakdown, endurance conditioning, dielectric withstand, and discharge performance - confirming suitability for use in telecom and industrial loop-powered systems where galvanic isolation integrity is critical. The 1SMB170AT3 is explicitly listed in the UL-certified device table on page 6 of the datasheet.
What is the thermal resistance from junction-to-lead (RJL) for the 1SMB170AT3?
The 1SMB170AT3 has a thermal resistance from junction-to-lead (RJL) of 40 °C/W, measured under conditions of zero lead length on a 1 in² copper pad (FR-4 board). This parameter governs heat transfer from the silicon die to the PCB copper via the leads, and is essential for calculating junction temperature rise during repetitive surge events. Derating begins above 75 °C ambient, with a linear reduction of 25 mW/°C beyond that point - a key consideration when designing for high-duty-cycle transient environments.
Can the 1SMB170AT3 be used in automotive applications requiring AEC-Q200 qualification?
No, the 1SMB170AT3 is not AEC-Q200 qualified. While it is widely used in automotive subsystems (e.g., ECUs, body control modules) due to its 600 W surge rating and 170 V VRWM, ON Semiconductor does not list it in their AEC-Q200 stress-tested product portfolio. For AEC-Q200-compliant alternatives with identical electrical specs, consider the SMAJ170A or SMCJ170A families - both of which carry full AEC-Q200 Grade 3 qualification and share the same VRWM, VC, and IPP values as the 1SMB170AT3.
1SMB170AT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- DO-214AA, SMB
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 170V
- Voltage - Breakdown (Min):
- 189V
- Voltage - Clamping (Max) @ Ipp:
- 275V
- Current - Peak Pulse (10/1000µs):
- 2.2A
- Power - Peak Pulse:
- 600W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 120pF @ 1MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB170AT3 FAQ
1.How can I place an order for 1SMB170AT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB170AT3 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 1SMB170AT3 reliable?
The price and inventory of 1SMB170AT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB170AT3 is usually 5 days.
3.What payment methods are accepted for 1SMB170AT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB170AT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB170AT3?
1SMB170AT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB170AT3 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 1SMB170AT3?
For technical support, including 1SMB170AT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB170AT3 requirements.
6.How does Aetrix verify that 1SMB170AT3 is sourced from the original manufacturer or authorized distributors?
All 1SMB170AT3 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 1SMB170AT3 meets industry standards.
7.What is the process for return or replacement of 1SMB170AT3?
All 1SMB170AT3 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB170AT3, 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 1SMB170AT3 part is unused and in its original packaging.
Return procedure for 1SMB170AT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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