Microchip Technology 1N5665

Overview

1N5665 from Microsemi (now Microchip) is a unidirectional transient voltage suppressor (TVS) diode in a hermetically sealed DO-13 metal package, designed for high-energy surge protection in harsh environments. It features a 162 V rated standoff voltage (VWM), 180–190 V breakdown voltage (V(BR)), 287 V maximum clamping voltage (VC) at 5.2 A peak pulse current (IPP), and 1500 W peak pulse power rating at 10/1000 µs - commonly deployed in avionics power rail protection against secondary lightning and ESD.

For engineers reviewing the 1N5665 datasheet, 1N5665 pinout, 1N5665 application, or 1N5665 equivalent, key selection criteria include its unidirectional polarity, DO-13 through-hole mechanical robustness, sub-100 ps response time, IEC61000-4-2/4-4/4-5 compliance capability, and military-grade qualification path via JANTXV1N5665A.

Technical Context

The 1N5665 operates as a silicon avalanche diode, entering controlled reverse-biased breakdown above its VWM to clamp transients while maintaining low leakage (<5 µA at 162 V). Its thermal resistance is 50°C/W junction-to-lead (at 10 mm lead length), enabling reliable operation from –55°C to +175°C ambient.

It delivers 1500 W non-repetitive peak pulse power under 10/1000 µs waveform with <100 ps response, and supports forward surge current up to 200 A (8.3 ms half-sine). Cathode is internally connected to the metal case, enforcing unidirectional conduction and requiring correct PCB polarity alignment.

Key Specifications

Pinout & Package

DO-13 (DO-202AA) hermetically sealed metal-glass package with axial leads; cathode terminal electrically bonded to case and marked by diode symbol on body.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SMCJ160A and 1N5663A, the 1N5665 uniquely balances 162 V standoff, 287 V clamping, and hermetic DO-13 reliability - making it optimal for high-voltage avionics and industrial DC systems demanding long-term environmental resilience and military traceability.

Availability

1N5665 is available at Aetrix Electronics and suitable for aerospace power distribution, industrial motor drive control, avionics sensor interface, and railway signaling power supply requiring stable component supply and long-lifecycle support.

Supply support for 1N5665 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 (acquired by Microchip Technology in 2018) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal components for aerospace, defense, and industrial markets.

The 1N5665 belongs to Microsemi's legacy JAN/JANTXV-qualified TVS diode family, engineered specifically for mission-critical surge protection in environments where hermetic sealing, radiation tolerance, and MIL-PRF-19500 compliance are mandatory.

FAQ

What is the maximum clamping voltage of the 1N5665 under standard test conditions?

The 1N5665 exhibits a maximum clamping voltage (VC) of 287 V when subjected to a 10/1000 µs surge waveform at 5.2 A peak pulse current (IPP), as specified in the Microsemi T4-LDS-0096 datasheet. This value defines the upper voltage limit imposed on protected circuits during transient events and is critical for ensuring downstream components remain within their absolute maximum ratings. The 1N5665 maintains this clamping performance across its full operating temperature range.

Is the 1N5665 suitable for IEC61000-4-5 secondary lightning protection?

Yes, the 1N5665 is explicitly rated for IEC61000-4-5 secondary lightning protection across multiple classes: Class 1 (42 Ω source) up to 1N5665A, Class 2 (12 Ω) up to 1N5651A, and Class 4 (2 Ω) up to 1N5636A. Its 1500 W peak pulse power and 287 V clamping voltage enable compliant protection of 162 V DC systems. The 1N5665 itself supports Class 1 testing at 42 Ω impedance, making it appropriate for telecom and transportation infrastructure applications.

Does the 1N5665 have a military-qualified version?

Yes, the JANTXV1N5665A is the fully screened military-qualified variant of the 1N5665, manufactured per MIL-PRF-19500/500 with tighter parameter tolerances, extended temperature validation, and full lot traceability. It shares the same DO-13 hermetic package and electrical characteristics but adds radiation hardness per MicroNote 050 and enhanced reliability testing - essential for DoD, NASA, and FAA-certified avionics programs. The base 1N5665 is commercial-grade only.

How does the DO-13 package of the 1N5665 improve reliability versus plastic TVS diodes?

The DO-13 package of the 1N5665 uses welded metal-glass hermetic sealing, eliminating moisture ingress and polymer outgassing risks inherent in plastic packages like DO-204AC. This construction delivers proven radiation hardness (per MicroNote 050), stable leakage current over decades, and immunity to thermal cycling fatigue - critical for aerospace and nuclear instrumentation. Unlike plastic alternatives, the 1N5665's DO-13 case also serves as the cathode terminal, enabling low-inductance grounding and superior thermal transfer to heatsinks or chassis.

What is the standby leakage current of the 1N5665 at its rated standoff voltage?

The 1N5665 specifies a maximum standby leakage current (ID) of 5 µA at its rated standoff voltage (VWM) of 162 V, measured at 25°C ambient. This ultra-low leakage ensures minimal power loss in always-on systems such as avionics power monitors or railway signaling controllers. Leakage remains well below 10 µA across the full –55°C to +125°C operating range, supporting energy-sensitive designs without compromising protection integrity.