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onsemi P6SMB18CAT3
- Part No.:
- P6SMB18CAT3
- Manufacturer:
- onsemi
- Category:
- TVS Diodes
- Package:
- -
- Datasheet:
-
P6SMB18CAT3.pdf
- Description:
- TVS ZENER BIDIR 600W 18V SMB
- Quantity:
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Inventory:9,983
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Product details
Overview
P6SMB18CAT3 from ON Semiconductor is a bidirectional 600 W transient voltage suppressor (TVS) diode designed for parallel overvoltage protection of DC power rails and signal lines. It features a 15.3 V working peak reverse voltage (VRWM), 18 V nominal Zener breakdown voltage (VBR), clamps to ≤25.2 V at 24 A peak pulse current (IPP), and responds in <1 ns - used in automotive power supply input stages, industrial PLC I/O modules, and medical equipment surge interfaces.
For engineers reviewing the P6SMB18CAT3 datasheet, pinout, applications, or equivalent options, key selection criteria include VRWM ≥ system operating voltage, clamping voltage margin below IC absolute maximum ratings, UL 497B certification for isolated loop protection, and SMB package thermal performance under repetitive surge conditions.
Technical Context
The P6SMB18CAT3 operates as a bidirectional avalanche diode with symmetrical clamping behavior on both polarities, enabling protection against positive and negative transients without polarity sensitivity. Its low zener impedance and fast <1 ns response time ensure minimal overshoot during ESD or lightning-induced surges.
It is rated for 600 W non-repetitive peak power at 1 ms pulse width (10/1000 µs waveform), with thermal derating to 0.55 W at 25°C ambient and junction-to-ambient thermal resistance of 226°C/W on FR-4 board. The device meets AEC-Q101 for automotive use and carries UL 497B recognition for isolated loop circuit protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VRWM | 15.3 V - minimum reverse standoff voltage; must exceed circuit's max continuous DC or peak AC voltage to avoid leakage conduction during normal operation |
| VBR @ IT=1 mA | 17.1–18.9 V - Zener breakdown range; defines onset of avalanche conduction under standardized test current |
| VC @ IPP=24 A | 25.2 V - maximum clamped voltage during 10/1000 µs surge; determines worst-case stress on downstream components |
| IPP | 24 A - peak pulse current at which VC is specified; correlates directly with 600 W surge capability at 1 ms |
| IR @ VRWM | <5 µA - reverse leakage current at 15.3 V; ensures negligible standby power loss and signal integrity in high-impedance circuits |
| Junction Capacitance | 545 pF @ 0 V - affects high-frequency transient filtering and signal line bandwidth; relevant for data line protection |
| ESD Rating | Class 3 HBM (>16 kV) - qualifies for direct handling in uncontrolled environments without additional ESD mitigation |
Pinout & Package
Package: SMB (Case 403A), surface-mount, Pb-free, void-free thermosetting plastic housing with modified L-bend leads. Dimensions: 4.06–4.60 mm (E), 3.30–3.95 mm (D), 2.159–2.47 mm (A), 0.76–1.60 mm (L). Mounting position: any.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (marked side) | Avalanche conduction terminal (bidirectional) | Functions as cathode during positive transients and anode during negative transients; no polarity marking required per spec |
| Anode (unmarked side) | Avalanche conduction terminal (bidirectional) | Completes symmetrical conduction path; enables clamping on both voltage polarities without external bias |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional clamping | Enables single-device protection of AC-coupled or floating signal lines without polarity concerns or external rectification |
| UL 497B recognition | Validated for isolated loop circuit protection including strike voltage breakdown, endurance conditioning, and dielectric withstand tests |
| AEC-Q101 qualification | Qualified for automotive applications including engine control units, body electronics, and infotainment power inputs |
| Low clamping ratio (VC/VBR ≈ 1.4) | Minimizes voltage overshoot relative to breakdown threshold - critical for protecting 3.3 V/5 V logic with tight absolute maximum ratings |
| 600 W surge rating @ 1 ms | Withstands IEC 61000-4-5 Level 4 (4 kV) surges on 2 Ω source impedance when properly laid out with short traces |
Applications
| Automotive Power Input Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: 12 V battery-fed ECUs exposed to load dump (ISO 16750-2) and jump-start transients. IC Role / Device Role / Timing Role: Parallel-connected TVS diode clamping transient energy before it reaches DC-DC converters and microcontrollers. Use Value: Clamps to 25.2 V at 24 A, staying well below 36 V absolute max rating of common automotive PMICs and ensuring system survival per ISO 7637-2. |
Use Scenario: 24 V digital input channels in programmable logic controllers subjected to field-wiring induced surges. IC Role / Device Role / Timing Role: Standoff protection element placed across input terminals to shunt induced transients before optocoupler input stage. Use Value: 15.3 V VRWM matches typical 24 V nominal input range while allowing margin for ripple; UL 497B supports certified isolation barrier compliance. |
| Medical Equipment Signal Interface | AC-DC Adapter Secondary-Side Protection |
Use Scenario: Isolated sensor interfaces in patient-monitoring devices where ESD and EFT immunity are mandated by IEC 60601-1-2. IC Role / Device Role / Timing Role: Bidirectional clamp on differential analog front-end lines (e.g., ECG leads) referenced to isolated ground. Use Value: Symmetrical <1 ns response prevents polarity-dependent delay skew; 545 pF capacitance avoids signal distortion in sub-10 kHz biopotential bands. |
Use Scenario: Secondary-side output of 12 V wall adapters exposed to mains-borne surges coupled through transformer parasitics. IC Role / Device Role / Timing Role: Final-stage overvoltage limiter placed after secondary rectifier and bulk capacitor to protect connected loads. Use Value: 600 W peak power handles multiple repetitions of IEC 61000-4-5 surges; low leakage (<5 µA) prevents capacitor discharge during standby. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ18A | Unidirectional; 18 V VBR; 23.2 V VC @ 23.3 A; SMA package (smaller footprint, higher RJA = 290°C/W) | Limited to DC-biased rails where polarity is fixed; less suitable for AC or floating signals | Select when space-constrained and polarity is known; verify thermal margin due to higher thermal resistance |
| 1.5KE18CA | Through-hole; 18 V VBR; 25.5 V VC @ 23.5 A; 1500 W peak power; TO-218 package | Higher surge capacity but incompatible with SMT assembly; requires PCB real estate and wave soldering | Choose for legacy designs or high-reliability systems requiring proven through-hole robustness and manual rework access |
Compared with P6SMB18CAT3, SMAJ18A offers smaller size but lacks bidirectional capability and has inferior thermal performance, while 1.5KE18CA delivers higher surge rating but eliminates SMT compatibility - making P6SMB18CAT3 optimal for new SMT-based automotive and industrial designs needing balanced performance, certification, and manufacturability.
Availability
P6SMB18CAT3 is available at Aetrix Electronics and suitable for automotive electronic control units, industrial programmable logic controllers, and medical diagnostic equipment requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for P6SMB18CAT3 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, sensing, and connectivity solutions for automotive, industrial, and cloud power applications.
The P6SMB18CAT3 belongs to ON Semiconductor's P6SMBxxCAT3G series of 600 W SMB-packaged TVS diodes, engineered specifically for cost-sensitive, high-volume surge protection in automotive and industrial systems requiring UL 497B and AEC-Q101 compliance.
FAQ
What is the clamping voltage of the P6SMB18CAT3 under surge conditions?
The P6SMB18CAT3 clamps to a maximum of 25.2 V when subjected to its rated peak pulse current of 24 A (10/1000 µs waveform). This value is measured per standard test conditions in the datasheet and represents the worst-case voltage seen by protected circuitry during a surge event. Designers must ensure this clamping level remains safely below the absolute maximum voltage rating of downstream ICs.
Is the P6SMB18CAT3 suitable for automotive applications?
Yes, the P6SMB18CAT3 is AEC-Q101 qualified and PPAP capable, making it suitable for automotive applications including engine control units, body control modules, and infotainment power supplies. Its UL 497B recognition further supports use in safety-critical isolated subsystems such as battery management interfaces and sensor signal conditioning.
Does the P6SMB18CAT3 have polarity markings on the package?
No, the P6SMB18CAT3 is a bidirectional TVS diode and does not require polarity marking per its datasheet specification. The device functions identically regardless of orientation in the circuit, simplifying layout and eliminating risk of incorrect placement during automated assembly.
What is the thermal resistance of the P6SMB18CAT3 on a standard FR-4 PCB?
The P6SMB18CAT3 has a junction-to-ambient thermal resistance (RJA) of 226°C/W when mounted on an FR-4 board using ON Semiconductor's minimum recommended footprint. This value assumes standard JEDEC test conditions and must be factored into reliability calculations for applications with repetitive surge events or elevated ambient temperatures.
How does the P6SMB18CAT3 differ from unidirectional TVS diodes like SMAJ18A?
The P6SMB18CAT3 is bidirectional and clamps transients of either polarity, whereas SMAJ18A is unidirectional and only protects against positive-going surges relative to its cathode. This makes P6SMB18CAT3 appropriate for AC-coupled lines, floating references, or systems where voltage polarity cannot be guaranteed - unlike SMAJ18A, which requires correct DC bias alignment.
P6SMB18CAT3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Package/Case:
- -
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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:
- -
P6SMB18CAT3 FAQ
1.How can I place an order for P6SMB18CAT3 through Aetrix?
Please submit a Request for Quotation (RFQ) for P6SMB18CAT3 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 P6SMB18CAT3 reliable?
The price and inventory of P6SMB18CAT3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for P6SMB18CAT3 is usually 5 days.
3.What payment methods are accepted for P6SMB18CAT3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for P6SMB18CAT3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for P6SMB18CAT3?
P6SMB18CAT3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your P6SMB18CAT3 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 P6SMB18CAT3?
For technical support, including P6SMB18CAT3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your P6SMB18CAT3 requirements.
6.How does Aetrix verify that P6SMB18CAT3 is sourced from the original manufacturer or authorized distributors?
All P6SMB18CAT3 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 P6SMB18CAT3 meets industry standards.
7.What is the process for return or replacement of P6SMB18CAT3?
All P6SMB18CAT3 units undergo pre-shipment inspection (PSI). If there is an issue with P6SMB18CAT3, 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 P6SMB18CAT3 part is unused and in its original packaging.
Return procedure for P6SMB18CAT3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
P6SMB18CAT3 Tags
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