Microchip Technology 1N5369E3/TR8

Overview

1N5369E3/TR8 from Microsemi is a 51 V, ±5% tolerance, 5 W axial-leaded silicon Zener diode optimized for precision voltage regulation in power supply feedback loops, overvoltage protection circuits, and reference voltage generation. It delivers 25 mA test current, 27 Ω dynamic impedance at 25°C, and supports steady-state operation up to 150°C with 25°C/W junction-to-lead thermal resistance.

For engineers reviewing the 1N5369E3/TR8 datasheet, 1N5369E3/TR8 pinout, 1N5369E3/TR8 application, or 1N5369E3/TR8 equivalent, key selection criteria include Zener voltage accuracy, surge current capability (230 A), low voltage regulation drift (±2.5 V), and RoHS-compliant matte-tin plating for reliable solderability.

Technical Context

This discrete Zener diode operates in reverse breakdown mode with cathode-banded polarity, requiring the banded end to be held positive relative to the anode. Its regulation performance is specified at 25°C lead temperature (TL), with voltage measurement taken 40 ±10 ms after DC current application.

The device uses void-free thermosetting epoxy encapsulation (UL94V-0), achieves IPC/JEDEC J-STD-020B Level 1 moisture sensitivity, and exhibits minimal voltage variation versus current-ΔVZ = 2.5 V between 10% and 50% of IZM-enabling stable reference behavior across load transients.

Key Specifications

Pinout & Package

Package: Axial-leaded T-18 plastic case (void-free UL94V-0 epoxy), cathode indicated by band, RoHS-compliant matte-tin plated leads, weight 0.7 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5369B and MMSZ5255B-TP, the 1N5369E3/TR8 uniquely combines RoHS compliance, 5 W power handling, axial-leaded mechanical robustness, and 230 A surge capability-making it irreplaceable in high-reliability 48 V industrial power systems requiring field-serviceable through-hole mounting.

Availability

1N5369E3/TR8 is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial overvoltage clamps, and programmable reference sources requiring stable component supply and long-term obsolescence management.

Supply support for 1N5369E3/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 and mixed-signal components for aerospace, defense, and industrial markets.

The 1N53xxB series was designed specifically for ruggedized voltage regulation in harsh-environment power systems-emphasizing surge survivability, wide temperature operation, and JEDEC-standardized mechanical interchangeability.

FAQ

What is the Zener voltage tolerance of the 1N5369E3/TR8?

The 1N5369E3/TR8 has a Zener voltage tolerance of ±5%, confirmed by its "B" suffix per Microsemi's datasheet. This means its regulated voltage falls within 48.45 V to 53.55 V at 25°C lead temperature with 25 mA test current. The e3 suffix indicates RoHS compliance but does not affect voltage tolerance. This tolerance is tighter than standard ±10% (A suffix) or ±20% (no suffix) variants, making the 1N5369E3/TR8 suitable for applications demanding higher reference accuracy.

Does the 1N5369E3/TR8 require a heatsink for continuous 5 W operation?

Yes-the 1N5369E3/TR8 achieves its full 5.0 W power dissipation rating only when lead temperature (TL) is maintained below 25°C, typically achieved using ≥10 mm lead length from the body as a thermal path. On a standard FR4 board with 1 oz copper, its steady-state power drops to 1.47 W at 25°C ambient. For sustained 5 W operation, external heatsinking or forced-air cooling is required. The 25°C/W junction-to-lead thermal resistance directly informs this thermal design requirement for the 1N5369E3/TR8.

What does the "TR8" suffix mean in 1N5369E3/TR8?

The "TR8" suffix in 1N5369E3/TR8 denotes tape-and-reel packaging per EIA-296 standard, with 800 units per reel. This format enables automated pick-and-place assembly in high-volume manufacturing. The base part number 1N5369E3 specifies the RoHS-compliant 51 V Zener diode; "TR8" adds packaging configuration without altering electrical or thermal specifications. Customers ordering 1N5369E3/TR8 receive factory-sealed reels ready for SMT line integration.

Can the 1N5369E3/TR8 be used in place of the 1N5369B?

Yes-the 1N5369E3/TR8 is a direct RoHS-compliant replacement for the 1N5369B, sharing identical electrical parameters (51 V ±5%, 5 W, 25 mA I_ZT, 27 Ω Z_Z) and mechanical dimensions (T-18 axial package). The only differences are matte-tin plating (vs. tin-lead) and elimination of dry-pack requirements due to Level 1 moisture sensitivity. No PCB layout or schematic changes are needed when substituting 1N5369E3/TR8 for 1N5369B in existing designs.

What is the maximum reverse current (I_R) for the 1N5369E3/TR8 at rated voltage?

The maximum reverse current (I_R) for the 1N5369E3/TR8 is 0.5 μA when tested at 38.3 V (75% of nominal V_Z = 51 V), per Microsemi's electrical characteristics table. This ultra-low leakage ensures minimal power loss in standby mode and high impedance in off-state applications. The value is consistent across all B-suffix parts in the 1N53xxB series and reflects the device's suitability for precision biasing and low-current reference circuits where leakage could degrade accuracy.