Microchip Technology 1N5342A/TR8

Overview

1N5342A/TR8 from Microsemi is a silicon 5 W axial-leaded Zener diode with nominal regulation voltage of 6.8 V, ±10% tolerance (A suffix), 175 mA test current (IZT), 1.0 Ω maximum dynamic impedance (ZZ), and 700 mA maximum Zener current (IZM) at 25°C. It operates from –65°C to +150°C and is used for precision voltage reference and overvoltage protection in power supply feedback loops.

For engineers reviewing the 1N5342A/TR8 datasheet, 1N5342A/TR8 pinout, 1N5342A/TR8 application, or 1N5342A/TR8 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (25 °C/W junction-to-lead), surge current rating (11.5 A), voltage regulation (ΔVZ = 0.15 V), and RoHS-compliant matte-tin plating per MIL-STD-750.

Technical Context

This discrete Zener diode functions as a two-terminal voltage regulator by maintaining a stable reverse-biased breakdown voltage across its cathode–anode terminals. Its low dynamic impedance (1.0 Ω) ensures minimal voltage variation under load changes, while its 25 °C/W junction-to-lead thermal resistance supports reliable operation up to 5 W when mounted with ≥10 mm lead length from body.

The device exhibits 10 μA maximum reverse leakage at VR = 5.2 V, 0.15 V maximum voltage regulation (ΔVZ) between 10% and 50% of IZM, and withstands non-recurrent 8.3 ms half-sine surge currents up to 11.5 A - critical for transient suppression in industrial DC rails.

Key Specifications

Pinout & Package

Package: T-18 axial-leaded plastic encapsulated case per JEDEC DO-41 standard; void-free UL94V-0 epoxy body; cathode indicated by band; leads plated with RoHS-compliant annealed matte tin.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener regulation applications.

Compared with 1N5342A/TR8, the 1N5342B/TR8 offers improved voltage accuracy without trade-offs in power or surge capability, while the MMBZ5235B-TP sacrifices 50× power handling and 100× surge current for miniaturization - making it unsuitable as a direct replacement in high-energy applications.

Availability

1N5342A/TR8 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, sensor interface circuits, and telecom DC-DC converter feedback networks requiring stable component supply and long-term obsolescence management.

Supply support for 1N5342A/TR8 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 (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, RF, and radiation-hardened components for aerospace, defense, and industrial markets.

The 1N53xxA/B series was designed for robust, high-power voltage regulation in harsh-environment systems where thermal stability, surge resilience, and long-term parametric consistency are critical.

FAQ

What is the Zener voltage tolerance of the 1N5342A/TR8?

The 1N5342A/TR8 has a Zener voltage tolerance of ±10%, as indicated by the "A" suffix per Microsemi's documentation. This means its measured breakdown voltage at 175 mA falls between 6.12 V and 7.48 V at 25°C. The tolerance directly impacts system-level accuracy in feedback or reference applications, and users must account for this range in worst-case design analysis. Unlike the "B" suffix variant, the 1N5342A/TR8 does not guarantee tighter voltage bounds.

Does the 1N5342A/TR8 require dry packing before reflow soldering?

No, the 1N5342A/TR8 does not require dry packing prior to soldering. It carries IPC/JEDEC J-STD-020B Moisture Sensitivity Level 1 qualification, meaning it is immune to popcorning or delamination during standard reflow profiles. Its void-free UL94V-0 epoxy body and matte-tin leads are rated for 260°C for 10 seconds - fully compatible with lead-free assembly. This eliminates bake-out steps and reduces manufacturing overhead.

What is the maximum surge current rating for the 1N5342A/TR8?

The 1N5342A/TR8 is rated for a maximum non-recurrent surge current (IZSM) of 11.5 A, defined as the peak value of an 8.3 ms half-sine waveform. This rating reflects its ability to absorb transient energy without failure - essential for protecting downstream ICs in DC power rails exposed to inductive switching or load dump events. The surge capability is enabled by its 5 W power rating and low thermal resistance (25 °C/W).

How does the voltage regulation (ΔVZ) specification apply to the 1N5342A/TR8?

Voltage regulation (ΔVZ) for the 1N5342A/TR8 is specified as 0.15 V - the difference between its Zener voltage measured at 10% and 50% of IZM (700 mA), i.e., at 70 mA and 350 mA. This parameter quantifies how tightly the device maintains regulation across its usable current range. A low ΔVZ indicates superior line regulation, supporting stable references in variable-load applications such as sensor excitation or programmable current sources.

Can the 1N5342A/TR8 be used as a direct replacement for the 1N5342B/TR8?

The 1N5342A/TR8 is not a direct replacement for the 1N5342B/TR8 in designs requiring ±5% Zener voltage tolerance, as its ±10% tolerance introduces twice the voltage uncertainty. While both share identical nominal VZ (6.8 V), IZT (175 mA), ZZ (1.0 Ω), IZM (700 mA), and T-18 package, the wider tolerance may violate accuracy budgets in precision feedback loops. System validation is required if substituting 1N5342A/TR8 into a design originally qualified with 1N5342B/TR8.