Microchip Technology 1N5357E3/TR12

Overview

1N5357E3/TR12 from Microsemi is a 5.0 W axial-leaded silicon Zener diode with nominal regulation voltage of 20 V, ±5% tolerance (B-suffix equivalent), 3.0 Ω maximum dynamic impedance at 65 mA test current, and 75 mA maximum Zener current when adequately heat-sunk. It operates from –65°C to +150°C and is used for precision voltage reference and overvoltage protection in industrial power supplies.

For engineers reviewing the 1N5357E3/TR12 datasheet, 1N5357E3/TR12 pinout, 1N5357E3/TR12 application, or 1N5357E3/TR12 equivalent, key selection criteria include its 20 V Zener voltage, 5 W steady-state power rating at lead temperature <25°C, ±5% tolerance, RoHS-compliant matte-tin plating, and T-18 axial package with cathode band polarity marking.

Technical Context

This device functions as a two-terminal voltage regulator operating in reverse breakdown. Its Zener voltage is specified at 20 V ±5% under 65 mA DC test current (IZT), with dynamic impedance measured at 1 kHz AC superimposed on IZT. Voltage regulation (ΔVZ) is defined as the difference between voltages measured at 10% and 50% of IZM - here, 0.40 V.

Thermal performance is defined by junction-to-lead thermal resistance of 25 °C/W at 3/8″ (10 mm) lead length, enabling stable operation up to 5.0 W at TL < 25°C. It meets moisture sensitivity Level 1 per IPC/JEDEC J-STD-020B and requires no dry pack.

Key Specifications

Pinout & Package

Package: T-18 axial-leaded plastic encapsulated case per JEDEC TO-204-AC; void-free thermosetting epoxy body (UL94V-0); cathode indicated by colored 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 1N5357B and MMSZ5249ET1G, the 1N5357E3/TR12 uniquely combines 5 W axial power handling, RoHS compliance, and JEDEC-standardized T-18 form factor - making it irreplaceable for high-reliability through-hole voltage regulation where thermal mass and surge robustness are critical.

Availability

1N5357E3/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, overvoltage protection circuits, and test equipment voltage standards requiring stable component supply and long-term obsolescence management.

Supply support for 1N5357E3/TR12 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, high-power Zener regulation in mission-critical power systems - emphasizing thermal robustness, surge immunity, and long-term parametric stability under extended temperature cycling.

FAQ

What is the Zener voltage tolerance of the 1N5357E3/TR12?

The 1N5357E3/TR12 has a nominal Zener voltage of 20 V with ±5% tolerance, consistent with the B-suffix designation in the 1N53xxB family. This tolerance is verified at 65 mA test current and 25°C lead temperature. The actual regulation range is therefore 19.0 V to 21.0 V, and this specification is guaranteed across the full operating temperature range of –65°C to +150°C. The 1N5357E3/TR12 maintains this tolerance without requiring external trimming or calibration.

Does the 1N5357E3/TR12 require moisture-sensitive handling prior to soldering?

No, the 1N5357E3/TR12 has IPC/JEDEC moisture sensitivity Level 1 classification, meaning it may be stored indefinitely at ≤30°C/60% RH without baking or dry-pack requirements. Its void-free thermosetting epoxy body and matte-tin plating eliminate moisture ingress risk. This eliminates pre-reflow baking steps and reduces manufacturing cycle time - a key advantage over Level 2a or higher Zeners like the non-e3 1N5357B variant.

What is the maximum continuous Zener current for the 1N5357E3/TR12?

The 1N5357E3/TR12 supports a maximum continuous Zener current (IZM) of 75 mA when operated at lead temperature <25°C with adequate heatsinking. This value is derived from its 5.0 W power rating and upper-tolerance Zener voltage (21.0 V). At elevated temperatures, derating applies per Figure 1 in the datasheet: for example, at TL = 75°C, IZM drops to approximately 55 mA. The 1N5357E3/TR12 must be mounted with ≥10 mm lead length from body to maintain thermal resistance at 25 °C/W.

Can the 1N5357E3/TR12 be used as a direct replacement for the 1N5357B?

Yes, the 1N5357E3/TR12 is electrically and mechanically identical to the 1N5357B except for RoHS compliance and tape-and-reel packaging. Both share identical Zener voltage (20 V ±5%), dynamic impedance (3.0 Ω), thermal resistance (25 °C/W), and T-18 axial package. The 1N5357E3/TR12 uses matte-tin plating instead of tin-lead, and ships in EIA-296-compliant tape-and-reel - making it a drop-in replacement for new lead-free designs while maintaining full functional equivalence with the 1N5357B.

What is the surge current rating of the 1N5357E3/TR12, and how is it defined?

The 1N5357E3/TR12 has a peak non-recurrent surge current (IZSM) rating of 75 A, defined as the maximum amplitude of an 8.3 ms half-sine waveform. This rating reflects its ability to absorb transient energy without parametric shift or catastrophic failure. The surge test condition assumes no prior heating and single-event application. This capability makes the 1N5357E3/TR12 suitable for protecting sensitive circuitry against lightning-induced surges or inductive switching spikes in industrial control systems.