Microchip Technology 1N8159US/TR

Overview

1N8159US/TR from Microsemi is a unidirectional transient voltage suppressor (TVS) diode designed for high-reliability, high-frequency circuit protection. It delivers 150 W peak pulse power at 10/1000 µs, features 4 pF capacitance, 18.0 V working standoff voltage (V_WM), and clamps transients to ≤30.5 V at 11.7 A peak impulse current - ideal for ESD/EFT protection in RF front-ends and aerospace data links.

For engineers reviewing the 1N8159US/TR datasheet, 1N8159US/TR pinout, 1N8159US/TR application, or 1N8159US/TR equivalent, key selection criteria include low-capacitance transient suppression, hermetic glass packaging for radiation-hardened environments, Category 1 metallurgical bonding, IEC61000-4-2/4-4 compliance, and axial-leaded through-hole mounting compatibility.

Technical Context

This TVS employs a unique series-connected rectifier diode in anti-parallel configuration with the avalanche junction to achieve ultra-low 4 pF total capacitance while maintaining unidirectional operation. Its voidless hermetically sealed hard-glass package ensures stable performance across −55 °C to +175 °C junction temperature range and supports MIL-STD-750 Method 1020 ESD immunity.

The device operates with 0.5 µA maximum standby current at 18.0 V V_WM, breaks down at 20.9–23.1 V (min/max), and exhibits a +0.092 %/°C temperature coefficient of breakdown voltage - enabling predictable clamping behavior under thermal stress in avionics and satellite subsystems.

Key Specifications

Pinout & Package

Package: Axial-leaded, voidless hermetically sealed hard-glass case with tungsten slugs; cathode band marked on body; RoHS-compliant matte tin plating over copper leads; weight ≈340 mg.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMCJ18A and 1N6322, the 1N8159US/TR uniquely combines ultra-low 4 pF capacitance, hermetic glass construction, Category 1 bonding, and radiation tolerance - making it the only option qualified for high-frequency, high-reliability, and radiation-intensive applications without design compromises.

Availability

1N8159US/TR is available at Aetrix Electronics and suitable for RF transceiver protection, aerospace data bus safeguarding, satellite command receiver hardening, and downhole sensor interface conditioning requiring stable component supply across extended product lifecycles.

Supply support for 1N8159US/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 secure analog/mixed-signal solutions for aerospace, defense, and industrial markets.

The 1N8159US/TR belongs to Microsemi's legacy high-reliability TVS family, engineered specifically for mission-critical transient protection where failure is not an option - emphasizing hermeticity, low capacitance, and environmental survivability over cost or general-purpose utility.

FAQ

What is the clamping voltage of the 1N8159US/TR at its rated peak impulse current?

The 1N8159US/TR clamps to a maximum of 30.5 V when subjected to its rated 11.7 A peak impulse current (I_PP) under the standard 10/1000 µs waveform. This value is guaranteed across the full operating temperature range and ensures downstream components remain within safe voltage limits during surge events. The 1N8159US/TR maintains consistent clamping performance due to its stable avalanche characteristics and hermetic construction.

Is the 1N8159US/TR suitable for bidirectional transient protection?

The 1N8159US/TR is inherently unidirectional, but bidirectional protection can be implemented by connecting two 1N8159US/TR devices in anti-parallel configuration - as documented in Microsemi's Figure 5. This arrangement doubles the effective capacitance to 8 pF while preserving 150 W per-polarity surge capability and enabling symmetrical clamping on both signal polarities. No single-device bidirectional variant exists in this series.

Does the 1N8159US/TR meet IEC61000-4-5 for lightning surge immunity?

Yes, the 1N8159US/TR provides secondary lightning surge protection per select levels of IEC61000-4-5, enabled by its 150 W peak pulse power rating at the 10/1000 µs waveform and robust 30.5 V clamping voltage. It is intended for use in conjunction with primary protection stages (e.g., gas discharge tubes) in telecom and avionics interfaces where coordinated staging is required to meet Level 3 or Level 4 test requirements.

What is the thermal resistance and steady-state power rating of the 1N8159US/TR?

The 1N8159US/TR has a thermal resistance of 150 °C/W from junction to ambient and a steady-state average power rating of 1.0 W at 25 °C ambient temperature. This rating assumes adequate PCB thermal management - such as copper pour and thermal vias - to prevent junction temperature from exceeding +175 °C. Derating is required above 25 °C per the published derating curve in the datasheet.

How does the 1N8159US/TR achieve its 4 pF capacitance?

The 1N8159US/TR achieves its ultra-low 4 pF capacitance through a proprietary internal architecture that places a rectifier diode in series and opposite polarity to the main TVS junction. This configuration cancels displacement current during normal operation while preserving fast avalanche response during transients. The result is minimal signal distortion in high-frequency applications - a feature confirmed in Microsemi's T4-LDS-xxxx characterization data.