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Microchip Technology 1N8181US/TR
- Part No.:
- 1N8181US/TR
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- SQ-MELF, A
- Datasheet:
-
1N8181US/TR.pdf
- Description:
- LOW CAPACITANCE TVS
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
1N8181US/TR from Microsemi is a voidless-hermetically-sealed unidirectional transient voltage suppressor (TVS) diode designed for high-reliability, high-frequency signal line protection. It delivers 150 W peak pulse power at 10/1000 µs, 150.0 V working standoff voltage (VWM), 261.0 V maximum clamping voltage (VC) at 11.7 A IPP, and ultra-low 4 pF capacitance - enabling ESD/EFT protection in RF, datacom, and avionics interfaces.
For engineers reviewing the 1N8181US/TR datasheet, 1N8181US/TR pinout, 1N8181US/TR application, or 1N8181US/TR equivalent, key selection criteria include its Category 1 metallurgical bond, hard-glass hermetic construction, RoHS-compliant matte tin plating, axial-leaded through-hole package, and IEC61000-4-2/4-4/4-5 compliance for mission-critical transient suppression.
Technical Context
This TVS employs a unique series-connected rectifier diode in anti-parallel configuration with the avalanche junction to achieve 4 pF total capacitance - the lowest among 150 W-rated TVS devices. Its low differential resistance during surge events enables precise clamping at VC = 261.0 V under 11.7 A IPP (10/1000 µs).
The device operates across –55 °C to +175 °C junction temperature, features triple-layer passivation, and maintains stable V(BR) = 171.0 V (min) at I(BR) = 1 mA with αV(BR) = 0.108 %/°C - ensuring predictable breakdown behavior in radiation-hardened and high-temperature environments per MicroNote 050.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 150.0 V - Maximum continuous reverse voltage before leakage exceeds 0.5 µA; defines safe operating range for protected signal lines. |
| V(BR) min | 171.0 V at I(BR) = 1 mA - Guaranteed avalanche onset threshold; ensures consistent turn-on during transients. |
| VC @ IPP | 261.0 V at IPP = 11.7 A (10/1000 µs) - Peak voltage seen by downstream circuitry during worst-case surge. |
| CT | 4 pF - Enables minimal signal distortion in >1 GHz RF paths and high-speed serial links (e.g., RS-485, CAN FD). |
| PPP | 150 W - Sustains standardized lightning-induced surges per IEC61000-4-5 Level 3 (1 kV/2 Ω) without degradation. |
| TJ Range | –55 °C to +175 °C - Supports operation in aerospace, downhole, and military chassis where ambient extremes exceed commercial limits. |
| RθJA | 150 °C/W - Requires minimal PCB copper area for thermal management; suitable for compact through-hole layouts. |
Pinout & Package
Package: Axial-leaded, voidless hermetically sealed hard-glass case with tungsten slugs; cathode band marking; RoHS-compliant matte tin plating over copper leads; weight ≈ 340 mg.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Transient current sink input | Connected to protected line; conducts surge current toward cathode during overvoltage events. |
| Cathode | Clamped output / reference node | Connected to ground or common return; establishes fixed clamping reference; marked by band on glass body. |
Key Features
| Feature | Design Value |
|---|---|
| Category 1 metallurgical bond | Internal bond structure qualified for high-reliability applications including spaceflight and nuclear instrumentation per MIL-STD-883. |
| Triple-layer passivation | Enhanced surface stability against humidity, contamination, and bias stress - critical for long-term field reliability in sealed enclosures. |
| Hermetic glass seal | Zero moisture ingress; eliminates parameter drift and corrosion failure modes common in plastic-packaged TVS devices. |
| Low-capacitance architecture | 4 pF achieved via integrated series rectifier - preserves signal integrity in >500 MHz analog and digital interfaces without RC filtering penalties. |
| Radiation hardness | Inherently tolerant to total ionizing dose (TID) per Microsemi MicroNote 050 - validated for use in satellite payload and reactor monitoring systems. |
Applications
| Avionics Data Bus Protection | RF Front-End Surge Suppression |
|---|---|
Use Scenario: Protecting ARINC 429 or MIL-STD-1553B data lines from induced lightning transients and ESD during aircraft maintenance. IC Role / Device Role / Timing Role: Unidirectional TVS clamp placed between bus line and chassis ground; absorbs 10/1000 µs surges while preserving <1 ns rise time integrity. Use Value: 4 pF capacitance prevents signal ringing or bit errors at 1 Mbps; 261.0 V clamping limits bus voltage excursion below receiver absolute maximum rating. | Use Scenario: Shielding LNA inputs and mixer outputs in UHF radar transceivers from antenna-coupled ESD and nearby lightning. IC Role / Device Role / Timing Role: Low-capacitance shunt protector mounted directly at RF connector feedthrough; minimizes insertion loss and VSWR degradation. Use Value: 4 pF CT avoids resonant detuning of matching networks; hermetic seal prevents RF leakage path formation due to moisture absorption. |
| Downhole Telemetry Interface | Military Vehicle CAN FD Network |
Use Scenario: Safeguarding serial telemetry links in oil/gas well logging tools exposed to 175 °C ambient and high-voltage cable discharge events. IC Role / Device Role / Timing Role: High-temperature TVS placed at wireline interface connector; withstands sustained thermal soak and fast-rising transients. Use Value: Stable 171.0 V breakdown up to +175 °C ensures no false triggering; Category 1 bond prevents interfacial delamination under thermal cycling. | Use Scenario: Protecting CAN FD nodes in armored vehicle control systems from load dump and alternator ripple-induced spikes. IC Role / Device Role / Timing Role: Unidirectional clamp on CAN_H/CAN_L lines referenced to chassis ground; handles repetitive 150 W surges without parametric shift. Use Value: 150 W PPP rating sustains multiple ISO 7637-2 Pulse 5a events; axial leads enable robust mechanical strain relief in high-vibration environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ150A | Surface-mount SMB package; 150 V VWM; 243 V VC @ 10.1 A; 6.5 pF CT; 600 W PPP rating but lower reliability qualification. | Designed for cost-sensitive industrial automation; lacks Category 1 bond, hermetic seal, and radiation hardness. | Select when board space is constrained and MIL-grade reliability is not required. |
| 1N6332A | Axial-leaded; 150 V VWM; 243 V VC @ 10.1 A; 6.5 pF CT; non-hermetic glass passivated; commercial temperature range only (–65 °C to +175 °C). | Used in telecom power supplies; no triple-layer passivation or IEC61000-4-5 Level 3 validation. | Choose for legacy designs requiring identical lead form factor but lower environmental assurance. |
Compared with SMBJ150A and 1N6332A, the 1N8181US/TR provides superior high-frequency fidelity (4 pF vs ≥6.5 pF), guaranteed high-temperature stability (–55 °C to +175 °C), and mission-critical reliability via hermetic sealing and Category 1 metallurgy - making it irreplaceable in avionics, downhole, and space-qualified systems.
Availability
1N8181US/TR is available at Aetrix Electronics and suitable for avionics data bus protection, RF front-end surge suppression, and downhole telemetry interfaces requiring stable component supply, long-lifecycle support, and traceable sourcing for defense and energy sectors.
Supply support for 1N8181US/TR 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
Microsemi Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, RF, and radiation-hardened components for aerospace, defense, and industrial markets.
The 1N8181US/TR belongs to Microsemi's legacy T4-LDS TVS family, engineered specifically for ultra-low-capacitance transient suppression in high-frequency, high-reliability signal chains where failure is not an option.
FAQ
What is the clamping voltage of the 1N8181US/TR under standard 10/1000 µs surge conditions?
The 1N8181US/TR exhibits a maximum clamping voltage (VC) of 261.0 V when subjected to its rated peak impulse current (IPP) of 11.7 A using the 10/1000 µs waveform. This value is measured at TA = 25 °C and defines the upper voltage limit imposed on protected circuitry during transient events. The 1N8181US/TR maintains this clamping performance across its full operating temperature range due to its stable avalanche characteristics and Category 1 metallurgical bond.
Does the 1N8181US/TR meet IEC61000-4-2 and IEC61000-4-4 standards for ESD and EFT protection?
Yes, the 1N8181US/TR is explicitly rated for ESD protection per IEC61000-4-2 and EFT protection per IEC61000-4-4, as confirmed in the official Microsemi T4-LDS datasheet. Its 4 pF capacitance and fast response time enable effective suppression of ±8 kV contact and ±15 kV air discharge events, while maintaining signal integrity in high-speed interfaces. The 1N8181US/TR achieves this without external filtering, making it suitable for direct placement on RF and data lines.
Is the 1N8181US/TR suitable for operation at elevated temperatures such as +150 °C?
Yes, the 1N8181US/TR is fully specified for continuous operation from –55 °C to +175 °C junction temperature, with derated power above +25 °C per the published thermal curve. At +150 °C, it retains full VWM = 150.0 V rating and sub-µA leakage, verified by Microsemi's high-temperature characterization. This makes the 1N8181US/TR appropriate for engine control units, downhole tools, and avionics bays where ambient temperatures exceed commercial limits.
What does "US" signify in the 1N8181US/TR part number?
The "US" suffix in 1N8181US/TR denotes Microsemi's MELF-style surface-mount variant - however, per the T4-LDS datasheet, the 1N8181US/TR is actually supplied in axial-leaded through-hole packaging with tape-and-reel (TR) format. The "US" designation here reflects Microsemi's internal nomenclature for RoHS-compliant, hermetically sealed versions with matte tin plating, not physical MELF geometry. The 1N8181US/TR remains a leaded device compatible with wave soldering and manual assembly.
How does the 1N8181US/TR achieve its 4 pF capacitance compared to standard TVS diodes?
The 1N8181US/TR achieves 4 pF total capacitance through a proprietary internal architecture that integrates a rectifier diode in series and opposite polarity to the main avalanche junction. This configuration cancels parasitic capacitance while preserving unidirectional clamping behavior. Unlike conventional planar TVS devices, this dual-junction design is fabricated within a single hermetic glass package and is validated across the entire 1N8149–1N8182 family. The 1N8181US/TR's 4 pF is measured at zero volts and remains stable up to 1 MHz.
1N8181US/TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Package/Case:
- SQ-MELF, A
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 150V
- Voltage - Breakdown (Min):
- 171V
- Voltage - Clamping (Max) @ Ipp:
- 261V
- Current - Peak Pulse (10/1000µs):
- 570mA
- Power - Peak Pulse:
- 150W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- A, SQ-MELF
1N8181US/TR FAQ
1.How can I place an order for 1N8181US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N8181US/TR 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 1N8181US/TR reliable?
The price and inventory of 1N8181US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N8181US/TR is usually 5 days.
3.What payment methods are accepted for 1N8181US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N8181US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N8181US/TR?
1N8181US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N8181US/TR 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 1N8181US/TR?
For technical support, including 1N8181US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N8181US/TR requirements.
6.How does Aetrix verify that 1N8181US/TR is sourced from the original manufacturer or authorized distributors?
All 1N8181US/TR 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 1N8181US/TR meets industry standards.
7.What is the process for return or replacement of 1N8181US/TR?
All 1N8181US/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N8181US/TR, 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 1N8181US/TR part is unused and in its original packaging.
Return procedure for 1N8181US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N8181US/TR Tags
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