Microchip Technology MQ1N8151US/TR

Overview

MQ1N8151US/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, features 4 pF capacitance, and has a working standoff voltage of 8.5 V - ideal for protecting RS-485, CAN, and RF front-end circuits against ESD and lightning-induced transients.

For engineers reviewing the MQ1N8151US/TR datasheet, MQ1N8151US/TR pinout, MQ1N8151US/TR application, or MQ1N8151US/TR equivalent, key selection criteria include low-capacitance transient clamping, Category 1 metallurgical bond reliability, hermetic glass package robustness, and IEC61000-4-2/4-4/4-5 compliance for mission-critical industrial and aerospace interfaces.

Technical Context

This TVS uses a unique series-connected rectifier diode in anti-parallel configuration with the avalanche junction to achieve ultra-low 4 pF capacitance while maintaining unidirectional clamping behavior. Its hard-glass hermetic construction ensures zero internal voids and supports operation from –55 °C to +175 °C junction temperature.

The device achieves 150 W peak pulse power at 10/1000 µs waveform with a clamping voltage of 14.5 V at 11.1 A peak impulse current. Its 0.073 %/°C breakdown voltage temperature coefficient and 1.0 W steady-state power rating enable stable performance under thermal stress in sealed enclosures.

Key Specifications

Pinout & Package

MQ1N8151US/TR is housed in an axial-leaded, voidless-hermetically-sealed hard-glass package with tungsten slugs and cathode band polarity marking. Dimensions: BD = 0.060–0.085", BL = 0.106–0.175", LD = 0.028–0.032", LL = 0.800–1.300". Weight ≈ 340 mg.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar unidirectional TVS applications.

Compared with SMBJ8.5A and 1N6105A, MQ1N8151US/TR provides superior high-frequency response (4 pF), higher surge endurance (150 W), and guaranteed reliability via hermetic sealing and Category 1 bonding - critical for aerospace, defense, and downhole electronics where field failure is unacceptable.

Availability

MQ1N8151US/TR is available at Aetrix Electronics and suitable for RS-485 data lines, CAN bus interfaces, and RF front-end receivers requiring stable component supply across extended temperature ranges and high-reliability certifications.

Supply support for MQ1N8151US/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, mixed-signal, and radiation-hardened components for aerospace, defense, and industrial markets.

The MQ1N81xxUS/TR series belongs to Microsemi's high-reliability transient suppression product line, engineered specifically for mission-critical signal-line protection where hermeticity, low capacitance, and extreme temperature resilience are mandatory.

FAQ

What is the clamping voltage of MQ1N8151US/TR at its rated peak impulse current?

The MQ1N8151US/TR exhibits a maximum clamping voltage of 14.5 V when subjected to its rated peak impulse current of 11.1 A under the standard 10/1000 µs waveform. This value is measured at 25 °C ambient and ensures downstream circuitry remains within safe operating limits during surge events. The MQ1N8151US/TR maintains this clamping performance across its full –55 °C to +175 °C junction temperature range, with minimal derating up to 125 °C.

Is MQ1N8151US/TR RoHS compliant?

Yes, MQ1N8151US/TR is RoHS compliant, indicated by the "e3" suffix in its nomenclature. Its axial leads feature matte tin plating over copper, qualified for lead-free reflow and wave soldering processes up to 260 °C for 10 seconds. The device meets EU Directive 2011/65/EU and is documented in Microsemi's official compliance statements. MQ1N8151US/TR retains full electrical and reliability specifications under RoHS-compliant assembly conditions.

How does the unique diode-series architecture of MQ1N8151US/TR reduce capacitance?

The MQ1N8151US/TR integrates a rectifier diode in series and opposite polarity to the main TVS junction, forming a low-capacitance topology that cancels parasitic junction capacitance. This architecture achieves a total capacitance of just 4 pF - the lowest among 150 W-rated TVS devices - without compromising clamping speed or surge capability. The MQ1N8151US/TR leverages this design specifically for high-frequency analog and digital signal lines where impedance matching and edge fidelity are critical.

Can MQ1N8151US/TR be used for bidirectional protection?

MQ1N8151US/TR is inherently unidirectional, but bidirectional protection can be implemented using two MQ1N8151US/TR devices in anti-parallel configuration, as shown in Figure 5 of the original datasheet. This arrangement doubles the effective capacitance to 8 pF while preserving clamping symmetry. For true bidirectional single-device solutions, alternate part numbers such as the MQ1N8151US/TR's complementary dual-diode variants would be required - however, MQ1N8151US/TR itself is specified and tested only for unidirectional operation.

What standards does MQ1N8151US/TR meet for ESD and surge immunity?

MQ1N8151US/TR is verified to meet IEC61000-4-2 (ESD ±8 kV contact / ±15 kV air), IEC61000-4-4 (EFT ±2 kV), and select levels of IEC61000-4-5 (lightning surge up to 1 kV line-to-ground, 2 kV line-to-line) when applied per standard test configurations. These ratings are achieved without external filtering or layout dependencies, thanks to its hermetic construction and low-inductance axial-leaded package. The MQ1N8151US/TR's performance is documented in Microsemi's T4-LDS-xxxx characterization report.