Microchip Technology MQ1N8179US/TR

Overview

MQ1N8179US/TR from Microsemi is a voidless-hermetically-sealed unidirectional transient voltage suppressor (TVS) designed for high-reliability, high-frequency signal line protection. It delivers 150 W peak pulse power at 10/1000 µs, 138 V working standoff voltage (VWM), and ultra-low 4 pF capacitance - enabling ESD/EFT protection per IEC61000-4-2/4-4 in RF front-ends and data links.

For engineers reviewing the MQ1N8179US/TR datasheet, MQ1N8179US/TR pinout, MQ1N8179US/TR application, or MQ1N8179US/TR equivalent, key selection criteria include clamping voltage (208 V max at 1.95 A), low-leakage standby current (0.5 µA max), radiation-hardened construction, and Category 1 metallurgical bonding for aerospace and defense systems.

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 hard-glass hermetic package eliminates voids and supports operation from −55 °C to +175 °C junction temperature.

The device meets IEC61000-4-5 secondary lightning protection requirements and exhibits inherent radiation hardness per Microsemi MicroNote 050. Standby leakage remains ≤0.5 µA at 138 V VWM, and clamping occurs at 208 V under 1.95 A IPP (10/1000 µs), ensuring robust overvoltage suppression without signal distortion.

Key Specifications

Pinout & Package

MQ1N8179US/TR uses 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.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with SMCJ130A and 1N6377, MQ1N8179US/TR uniquely combines hermetic reliability, 4 pF capacitance, and radiation hardness - making it irreplaceable in RF-intensive, long-lifecycle, or safety-critical deployments where parameter drift or latent failure is unacceptable.

Availability

MQ1N8179US/TR is available at Aetrix Electronics and suitable for RF transceiver protection, avionics data bus interface, and downhole oilfield sensor modules requiring stable component supply across extended product lifecycles.

Supply support for MQ1N8179US/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, radiation-hardened, and aerospace-grade components.

MQ1N8179US/TR belongs to the 1N8149–1N8182 family of voidless-hermetically-sealed TVS diodes engineered for fail-safe transient protection in defense, space, and energy exploration systems where zero tolerance for field failure is mandated.

FAQ

What is the clamping voltage of MQ1N8179US/TR at its rated peak impulse current?

The MQ1N8179US/TR has a maximum clamping voltage (VC) of 208 V when subjected to its rated peak impulse current (IPP) of 1.95 A under the standard 10/1000 µs waveform. This value is measured at 25 °C and ensures downstream circuitry remains within safe voltage limits during surge events. The MQ1N8179US/TR maintains this clamping performance across its full operating temperature range due to its stable avalanche characteristics and hermetic construction.

Is MQ1N8179US/TR suitable for bidirectional transient protection?

No - MQ1N8179US/TR is a unidirectional TVS. For bidirectional protection, two MQ1N8179US/TR devices must be connected in anti-parallel, as documented in Figure 5 of the datasheet. This configuration doubles the effective capacitance to 8 pF but retains the same VWM and clamping behavior in both polarities. The MQ1N8179US/TR itself does not support symmetrical clamping in reverse bias.

Does MQ1N8179US/TR meet IEC61000-4-5 for lightning surge immunity?

Yes - MQ1N8179US/TR is specified for secondary lightning protection per select levels of IEC61000-4-5. Its 150 W peak pulse power rating at 10/1000 µs and 208 V clamping voltage enable compliance with Level 3 (1 kV line-to-earth, 2 kV line-to-line) and Level 4 (2 kV line-to-earth, 4 kV line-to-line) test configurations when properly implemented with appropriate series impedance. The MQ1N8179US/TR's low capacitance avoids resonance issues that compromise immunity in high-frequency systems.

What is the lead finish and RoHS status of MQ1N8179US/TR?

MQ1N8179US/TR features RoHS-compliant matte tin plating over copper leads, as indicated by the "e3" suffix in its nomenclature. The device conforms to EU Directive 2011/65/EU and is exempt from lead content restrictions under Annex III. Lead finish is controlled to ≤100 ppm Pb, and solderability is validated per J-STD-002. The MQ1N8179US/TR is fully compatible with lead-free reflow and wave soldering processes up to 260 °C for 10 seconds.

How does the voidless hermetic seal improve long-term reliability of MQ1N8179US/TR?

The voidless hermetic seal in MQ1N8179US/TR eliminates internal air pockets that could expand, contract, or oxidize under thermal cycling - preventing parameter drift, bond fatigue, or catastrophic failure over decades of operation. Unlike epoxy-packaged TVS diodes, the MQ1N8179US/TR's hard-glass enclosure maintains stable capacitance, leakage, and clamping voltage across −55 °C to +175 °C and >10,000 thermal cycles. This makes MQ1N8179US/TR suitable for infrastructure with 20+ year service life expectations.