Microchip Technology 1N4745PE3/TR12

Overview

1N4745PE3/TR12 from Microsemi is a 16 V, 5% tolerance, 1 W axial-lead Zener diode in DO-41 plastic package, rated for 15.5 mA test current, 16 Ω dynamic impedance at I_ZT, and 700 μA reverse leakage at 12.2 V, used for precision voltage regulation in power supply feedback loops and reference circuits.

For engineers reviewing the 1N4745PE3/TR12 datasheet, 1N4745PE3/TR12 pinout, 1N4745PE3/TR12 application, or 1N4745PE3/TR12 equivalent, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (45 °C/W junction-to-lead), surge current rating (285 mA), RoHS-compliant matte-tin plating, and JEDEC-standard DO-41 mechanical compatibility.

Technical Context

This device operates in reverse breakdown to maintain stable voltage across varying load and line conditions. Its 16 V nominal Zener voltage exhibits a positive temperature coefficient above ~5 V, with typical TC of +4.5 mV/°C per Figure 3, enabling predictable drift compensation in analog references.

The 1N4745PE3/TR12 delivers regulation over 1.0 mA to 285 mA operating current range, with knee impedance of 0.5 Ω at 1.0 mA test current and maximum forward voltage of 1.2 V at 200 mA - confirming suitability for bidirectional clamping and low-voltage reference biasing where forward conduction may occur during transients.

Key Specifications

Pinout & Package

DO-41 (DO-204AL) plastic axial-leaded package with cathode indicated by band; terminals are non-polarized leads - anode and cathode defined solely by band orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4745A and MMSZ4705T1G, the 1N4745PE3/TR12 uniquely combines full 1 W dissipation, JEDEC-standard DO-41 mounting, RoHS-compliant matte-tin plating, and tape-and-reel packaging - making it optimal for high-reliability through-hole power regulation where thermal management and compliance are critical.

Availability

1N4745PE3/TR12 is available at Aetrix Electronics and suitable for power supply feedback regulation, overvoltage protection clamping, and precision reference voltage generation requiring stable component supply across automotive, industrial control, and telecom infrastructure programs.

Supply support for 1N4745PE3/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, mixed-signal, and radiation-hardened components for aerospace, defense, and industrial markets.

The 1N47xxAP series was engineered for cost-effective, high-stability voltage regulation in legacy and new-design power systems where JEDEC-standard form factor and proven reliability are mandatory.

FAQ

What is the Zener voltage tolerance of the 1N4745PE3/TR12?

The 1N4745PE3/TR12 has a nominal Zener voltage of 16 V with a tolerance of ±5%, as confirmed by its "A" suffix per JEDEC standard and documented in Microsemi's REV C datasheet. This tolerance applies at 15.5 mA test current and 25 °C lead temperature. The 1N4745PE3/TR12 maintains this specification across its qualified operating temperature range of –65 °C to +150 °C.

Does the 1N4745PE3/TR12 support lead-free soldering processes?

Yes, the 1N4745PE3/TR12 features RoHS-compliant annealed matte-tin plating ("e3" suffix) and is rated for solder reflow at 260 °C for 10 seconds maximum, fully compatible with standard lead-free assembly processes. Its moisture sensitivity level is IPC/JEDEC J-STD-020B Level 1, eliminating the need for dry-packaging or baking prior to assembly.

What is the maximum steady-state current the 1N4745PE3/TR12 can regulate continuously?

The 1N4745PE3/TR12 supports a maximum steady-state Zener current of 62.5 mA at 16 V to sustain its full 1.0 W power rating - assuming lead temperature remains below 105 °C with ≥10 mm lead length from the body. At ambient temperatures above 45 °C on FR4 PCB, derating applies per Figure 1; the 1N4745PE3/TR12 must be thermally managed accordingly to avoid exceeding junction temperature limits.

How does the 1N4745PE3/TR12 differ from the glass-body 1N4745G variant?

The 1N4745PE3/TR12 uses plastic DO-41 encapsulation (P-suffix), delivering 45 °C/W junction-to-lead thermal resistance - significantly lower than the ~65 °C/W of the glass-body 1N4745G. This allows higher power handling in the same footprint. Both share identical electrical specs, but the 1N4745PE3/TR12 offers improved moisture resistance (Level 1 vs. Level 2a) and RoHS compliance.

Can the 1N4745PE3/TR12 be used in surface-mount designs?

No - the 1N4745PE3/TR12 is an axial-leaded DO-41 device and is not suitable for surface-mount assembly. For SMT equivalents, Microsemi offers the SMAJ4745A (SMA package) and MLL4745A (SOD-80), both sharing the same 16 V ±5% Zener voltage but differing in power rating, thermal performance, and mounting method. The 1N4745PE3/TR12 requires through-hole placement and wave or selective soldering.