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Microchip Technology MS1N8181US/TR
- Part No.:
- MS1N8181US/TR
- Manufacturer:
- Microchip Technology
- Category:
- TVS Diodes
- Package:
- SQ-MELF, A
- Datasheet:
-
MS1N8181US/TR.pdf
- Description:
- LOW CAPACITANCE TVS
- Quantity:
- Payment:
- Shipping:
Inventory:2,905
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Product details
Overview
MS1N8181US/TR from Microsemi is a voidless-hermetically-sealed unidirectional transient voltage suppressor (TVS) with 150 W peak pulse power, 4 pF capacitance, and 150 V working standoff voltage (VWM), designed for high-reliability ESD/EFT protection in RF front-ends and high-speed data lines.
For engineers reviewing the MS1N8181US/TR datasheet, MS1N8181US/TR pinout, MS1N8181US/TR application, or MS1N8181US/TR equivalent, this part delivers verified low-capacitance clamping for IEC61000-4-2/4-4-compliant circuits requiring stable VWM tolerance, Category 1 metallurgical bonding, and hard-glass robustness in axial-leaded mounting.
Technical Context
This TVS uses a unique series-connected rectifier diode in anti-parallel configuration to achieve ultra-low 4 pF capacitance while maintaining unidirectional clamping behavior. Its breakdown voltage is 171 V at 1 mA, with clamping voltage of 261 V at 1.95 A (10/1000 µs waveform).
Rated for -55 °C to +175 °C junction temperature, it features triple-layer passivation, RoHS-compliant matte tin plating, and internal Category 1 metallurgical bonds - all validated per MIL-STD-750 Method 1020 for ESD insensitivity and MicroNote 050 for inherent radiation hardness.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 150 V - Maximum continuous reverse standoff voltage before conduction begins; defines safe operating margin for signal line protection. |
| V(BR) | 171 V @ 1 mA - Breakdown voltage threshold where avalanche conduction initiates; ensures precise clamping onset. |
| VC | 261 V @ IPP = 1.95 A - Clamped voltage during 10/1000 µs surge; limits downstream voltage stress to protected ICs. |
| PPP | 150 W - Peak pulse power rating at 25 °C; supports robust lightning-level transients per IEC61000-4-5. |
| CT | 4 pF - Total small-signal capacitance at 0 V; enables use in >1 GHz RF paths without signal distortion. |
| TJ Range | -55 °C to +175 °C - Extended thermal operating envelope suitable for aerospace, downhole, and military environments. |
| RθJA | 150 °C/W - Junction-to-ambient thermal resistance; informs PCB copper area requirements for sustained power dissipation. |
Pinout & Package
MS1N8181US/TR is housed in an axial-leaded, voidless hermetically sealed hard-glass package with tungsten slugs and cathode band polarity marking. Leads are RoHS-compliant matte tin-plated copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Positive terminal under forward bias; connected to protected circuit ground or low-side reference. | Defines current path during clamping: surge enters cathode, exits anode to ground, limiting voltage across protected node. |
| Cathode | Negative terminal; marked by colored band; connects to protected signal line or power rail. | Acts as the "input" side for transient energy; voltage rise above VWM triggers avalanche conduction from cathode to anode. |
Key Features
| Feature | Design Value |
|---|---|
| Low capacitance architecture | 4 pF achieved via integrated anti-parallel rectifier diode - preserves signal integrity in 5G RF front-ends and USB 3.x interfaces. |
| Category 1 metallurgical bond | Internal high-reliability bond structure qualified for mission-critical applications including space-grade systems and avionics. |
| Triple-layer passivation | Hermetic glass encapsulation with three dielectric layers prevents moisture ingress and corrosion in harsh environmental exposure. |
| IEC61000-4-2/4-4 compliance | Validated ESD immunity up to ±15 kV contact discharge and EFT bursts up to 4 kV - meets industrial control and telecom standards. |
| Hard-glass mechanical construction | Robust voidless glass body withstands thermal shock, vibration, and mechanical stress beyond MIL-STD-202 requirements. |
Applications
| RF Transceiver Protection | Industrial Ethernet PHY Interface |
|---|---|
Use Scenario: Protecting LNA input stages and PA output matching networks in S-band radar transceivers exposed to lightning-induced surges. IC Role / Device Role / Timing Role: Unidirectional clamping device placed directly at antenna port to limit voltage excursion below IC damage threshold. Use Value: 4 pF capacitance avoids detuning of 2.4–3.5 GHz matching networks; 261 V clamping ensures GaAs MMICs remain within safe operating area. | Use Scenario: Safeguarding 10/100/1000BASE-T PHY differential pairs against ESD events on factory-floor automation equipment. IC Role / Device Role / Timing Role: Standoff-rated TVS mounted on PCB edge connectors to shunt fast transients before reaching magnetics or PHY IC. Use Value: 150 V VWM aligns with Ethernet common-mode voltage range; 150 W PPP handles multiple IEC61000-4-2 discharges without degradation. |
| Aerospace Data Bus Protection | Downhole Oilfield Sensor Interface |
Use Scenario: Securing ARINC 429 or MIL-STD-1553B data lines in flight control computers subjected to induced surges during electromagnetic interference testing. IC Role / Device Role / Timing Role: High-reliability TVS installed inline with twisted-pair bus traces to clamp common-mode transients without signal attenuation. Use Value: Category 1 metallurgical bond and -55 °C to +175 °C operation ensure uninterrupted function across aircraft operational envelope. | Use Scenario: Shielding pressure/temperature sensor analog outputs in subterranean drilling tools exposed to electrostatic discharge and cable discharge events. IC Role / Device Role / Timing Role: Low-leakage TVS (ID ≤ 0.5 µA at 150 V) placed at sensor module output to prevent false readings during transient coupling. Use Value: 0.5 µA standby current avoids loading 4–20 mA loop; radiation-hardened design maintains calibration stability in neutron-rich environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMCJ150A | Surface-mount DO-214AB package; 6.5 pF capacitance; 1500 W PPP rating; 219 V VC @ 6.9 A. | Higher clamping voltage and capacitance; suited for board-space-constrained but less frequency-sensitive designs. | Select when PCB real estate is limited and RF bandwidth < 500 MHz; not suitable for direct replacement due to different package and capacitance. |
| 1N6330 | Axial-leaded, 150 W, 150 V VWM, but 12 pF capacitance and no Category 1 bond or radiation hardness validation. | Lacks triple-layer passivation and MIL-STD-750 ESD qualification; rated only to +150 °C junction temperature. | Acceptable for commercial-grade industrial controls where radiation hardness and extended temperature are not required. |
Compared with SMCJ150A and 1N6330, MS1N8181US/TR uniquely combines 4 pF capacitance, Category 1 reliability bonding, and -55 °C to +175 °C operation - making it irreplaceable for RF, aerospace, and downhole applications demanding both signal fidelity and extreme environmental resilience.
Availability
MS1N8181US/TR is available at Aetrix Electronics and suitable for RF transceiver protection, industrial Ethernet PHY interface, aerospace data bus protection, and downhole oilfield sensor interface requiring stable component supply across long-lifecycle programs.
Supply support for MS1N8181US/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 and mixed-signal ICs, RF solutions, and radiation-hardened components for defense, aerospace, and industrial markets.
The MS1N8181US/TR belongs to Microsemi's legacy 1N81xx series of hermetically sealed TVS diodes, engineered specifically for mission-critical transient protection where failure is not an option - especially in RF, avionics, and harsh-environment sensing.
FAQ
What is the clamping voltage of MS1N8181US/TR at its rated peak surge current?
The clamping voltage (VC) of MS1N8181US/TR is 261 V at a peak impulse current (IPP) of 1.95 A under the standard 10/1000 µs waveform. This value is measured at 25 °C ambient and defines the maximum voltage seen by downstream circuitry during a transient event. The MS1N8181US/TR maintains this clamping performance across its full operating temperature range due to its stable avalanche characteristics and hard-glass packaging.
Is MS1N8181US/TR RoHS compliant?
Yes, MS1N8181US/TR is RoHS compliant, indicated by the "e3" suffix in its nomenclature. Its axial leads feature matte tin plating over copper, fully conforming to Directive 2011/65/EU. The device also meets JEDEC J-STD-020 moisture sensitivity level (MSL) requirements for through-hole assembly processes, with no special handling needed prior to soldering at 260 °C for 10 seconds.
Does MS1N8181US/TR support bidirectional transient protection?
No, MS1N8181US/TR is strictly unidirectional. Bidirectional protection requires two MS1N8181US/TR devices mounted in anti-parallel configuration, as documented in Figure 5 of the original Microsemi datasheet. This arrangement doubles total capacitance to 8 pF but provides symmetrical clamping for AC-coupled or floating signal lines - a trade-off explicitly validated for IEC61000-4-5 secondary lightning protection.
What is the maximum steady-state power dissipation for MS1N8181US/TR?
The maximum steady-state (average) power dissipation for MS1N8181US/TR is 1.0 W at TA = 25 °C, governed by its thermal resistance of 150 °C/W. This rating assumes adequate PCB copper area for heat spreading; derating is required above 25 °C ambient per the published derating curve (Figure 3). Continuous DC power must remain well below this limit to avoid junction temperature exceeding +175 °C.
How does the "MS" prefix in MS1N8181US/TR indicate its reliability grade?
The "MS" prefix in MS1N8181US/TR denotes JANS (Joint Army-Navy-Specification) qualification - the highest military reliability level, including screening to MIL-PRF-19500/510 requirements. This includes burn-in, temperature cycling, and hermeticity testing. The "MS" grade confirms Category 1 metallurgical bonding, radiation hardness per MicroNote 050, and full compliance with MIL-STD-750 Method 1020 for ESD insensitivity - distinguishing it from commercial (blank), JAN (MQ), or JANTXV (MX) variants.
MS1N8181US/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
MS1N8181US/TR FAQ
1.How can I place an order for MS1N8181US/TR through Aetrix?
Please submit a Request for Quotation (RFQ) for MS1N8181US/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 MS1N8181US/TR reliable?
The price and inventory of MS1N8181US/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MS1N8181US/TR is usually 5 days.
3.What payment methods are accepted for MS1N8181US/TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MS1N8181US/TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MS1N8181US/TR?
MS1N8181US/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MS1N8181US/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 MS1N8181US/TR?
For technical support, including MS1N8181US/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MS1N8181US/TR requirements.
6.How does Aetrix verify that MS1N8181US/TR is sourced from the original manufacturer or authorized distributors?
All MS1N8181US/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 MS1N8181US/TR meets industry standards.
7.What is the process for return or replacement of MS1N8181US/TR?
All MS1N8181US/TR units undergo pre-shipment inspection (PSI). If there is an issue with MS1N8181US/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 MS1N8181US/TR part is unused and in its original packaging.
Return procedure for MS1N8181US/TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MS1N8181US/TR 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
-
D12V0L1B2LP-7B
Diodes Incorporated
-
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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