Microchip Technology 1N4747P/TR12

Overview

1N4747P/TR12 from Microsemi is a 20 V, 1 W axial-lead Zener diode in DO-41 plastic package with ±5% voltage tolerance, 22 Ω dynamic impedance at 12.5 mA test current, and 0.25 A maximum regulator current at 50°C. It provides stable voltage regulation in power supply feedback loops, reference circuits, and overvoltage protection.

For engineers reviewing the 1N4747P/TR12 datasheet, 1N4747P/TR12 pinout, 1N4747P/TR12 application, or 1N4747P/TR12 equivalent, key selection factors include its 20 V nominal Zener voltage, 12.5 mA test current, 22 Ω Zener impedance, -65°C to +150°C operating temperature range, and DO-41 mechanical compatibility with standard through-hole PCB layouts.

Technical Context

The 1N4747P/TR12 operates in reverse breakdown mode with a sharp knee at 20 V, delivering regulation across 0.25 A max DC current and surviving 225 mA surge pulses. Its thermal resistance is 45°C/W junction-to-lead (3/8" lead length) and 105°C/W junction-to-ambient on FR4 board.

Designed for fixed-voltage reference and clamping, it exhibits 0.05%/°C typical temperature coefficient near 20 V, forward voltage ≤1.2 V at 200 mA, and meets MIL-STD-750 ESD immunity per Method 1020 without sensitivity concerns.

Key Specifications

Pinout & Package

DO-41 (DO-204AL) plastic axial-lead package with cathode indicated by color band; leads are tin-lead or RoHS-compliant matte tin, solderable per MIL-STD-750 Method 2026.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4747A and MMSZ4702T1G, the 1N4747P/TR12 uniquely combines 1 W power handling, DO-41 through-hole reliability, and EIA-296 tape-and-reel automation support - making it optimal for high-volume industrial power supply manufacturing where thermal robustness and placement efficiency are jointly critical.

Availability

1N4747P/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, analog sensor conditioning circuits, and embedded system voltage supervisors requiring stable component supply and long-term manufacturability.

Supply support for 1N4747P/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, RF, and timing components for aerospace, defense, and industrial markets.

The 1N47xxA series was developed to deliver JEDEC-standardized, high-stability Zener regulation in cost-effective plastic packages for general-purpose power management and reference applications.

FAQ

What is the Zener voltage tolerance for 1N4747P/TR12?

The 1N4747P/TR12 has a nominal Zener voltage of 20 V with a tolerance of ±5%, as indicated by the "A" suffix in the JEDEC part number. This tolerance is specified at 12.5 mA test current and 25°C lead temperature. The device maintains regulation within this band across its rated current and temperature range, supporting designs where moderate precision is sufficient without requiring tighter-tolerance variants like "C" (±2%) or "D" (±1%).

Does 1N4747P/TR12 support automated assembly?

Yes, the "TR12" suffix on 1N4747P/TR12 indicates EIA-296 compliant tape-and-reel packaging in 12 mm carrier tape, enabling direct use in pick-and-place machines. The DO-41 body geometry and lead spacing are compatible with standard axial-lead feeders. This eliminates manual handling and improves placement accuracy and throughput in high-volume PCB assembly lines.

What is the maximum continuous current for 1N4747P/TR12 at elevated temperatures?

The 1N4747P/TR12 supports up to 0.25 A maximum regulator current at 50°C ambient or lead temperature. Above 50°C, derating applies per Figure 1 in the datasheet: power dissipation decreases linearly to zero at 150°C. At 105°C lead temperature, usable current drops to approximately 0.125 A. Thermal design must account for 45°C/W junction-to-lead resistance and PCB copper area.

How does the DO-41 package of 1N4747P/TR12 compare to glass-body alternatives?

The "P" suffix in 1N4747P/TR12 denotes plastic DO-41 construction, which offers lower thermal resistance (45°C/W vs. ~60°C/W for glass-body "G" variants) and eliminates moisture sensitivity concerns (MSL Level 1, no dry pack required). Plastic encapsulation also improves mechanical ruggedness and reduces risk of breakage during handling or wave soldering versus fragile glass bodies.

Is 1N4747P/TR12 RoHS compliant?

Yes, 1N4747P/TR12 is offered in RoHS-compliant form with annealed matte-tin plating, as confirmed by the "e3" designation in Microsemi's official documentation. This version meets EU Directive 2011/65/EU and is suitable for environmentally regulated markets. Standard tin-lead terminations remain available for legacy applications requiring Pb-based solder compatibility.