Microchip Technology 1N4756APE3/TR12

Overview

1N4756APE3/TR12 from Microsemi is a 1.0 W axial-lead silicon Zener diode with nominal zener voltage of 47 V, ±5% tolerance (A suffix), 5.5 mA test current (IZT), 80 Ω dynamic impedance (ZZT), and 19 Ω knee impedance (ZZK) at 0.25 mA. It regulates voltage in power supply reference and overvoltage protection circuits across industrial temperature range.

For engineers reviewing the 1N4756APE3/TR12 datasheet, 1N4756APE3/TR12 pinout, 1N4756APE3/TR12 application, or 1N4756APE3/TR12 equivalent, key selection factors include its DO-41 package, 1500 mA maximum regulator current (IZM), 25 °C thermal resistance of 45 °C/W junction-to-lead, RoHS-compliant matte-tin plating, and tape-and-reel packaging (TR12).

Technical Context

This Zener operates in reverse breakdown to maintain stable 47 V regulation across 1.0–1500 mA operating current range. Its 80 Ω dynamic impedance at 5.5 mA IZT ensures low AC ripple rejection, while 19 Ω knee impedance at 0.25 mA IZK supports reliable turn-on at low bias currents.

Designed for ambient operation from –65 °C to +150 °C, it delivers 1.0 W dissipation at TL < 105 °C (3/8″ lead length) or TA < 45 °C on FR4 board. Forward voltage is ≤1.2 V at 200 mA, and polarity is marked by cathode band - operated with banded end positive for regulation.

Key Specifications

Pinout & Package

DO-41 (JEDEC DO-204AL) plastic molded package with axial leads; void-free UL94V-0 epoxy body; cathode indicated by single black band; tin-lead or RoHS-compliant matte-tin plating; weight 0.7 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4756A-T and MMBZ5270BS-7-F, the 1N4756APE3/TR12 uniquely combines 1 W power handling, DO-41 mechanical reliability, RoHS compliance, and EIA-296 tape-and-reel delivery - making it the only option qualified for high-volume, thermally demanding, and automated production of industrial power references.

Availability

1N4756APE3/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, telecom surge protectors, battery monitoring systems, and analog signal conditioning circuits requiring stable component supply and long-term lifecycle continuity.

Supply support for 1N4756APE3/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 RF solutions for aerospace, defense, and industrial markets.

The 1N47xxAP series was designed specifically for ruggedized voltage regulation in harsh-environment power systems - emphasizing thermal stability, ESD immunity, and moisture resilience across –65 °C to +150 °C operation.

FAQ

What is the zener voltage tolerance of the 1N4756APE3/TR12?

The 1N4756APE3/TR12 has a nominal zener voltage of 47 V with ±5% tolerance, indicated by the "A" suffix in the part number per JEDEC registration. This means the actual measured Vz at 5.5 mA test current falls between 44.65 V and 49.35 V under standard test conditions (TL = 25 °C, 90 s stabilization). The "e3" suffix confirms RoHS compliance but does not affect voltage tolerance.

Can the 1N4756APE3/TR12 be used in surface-mount designs?

No - the 1N4756APE3/TR12 uses a DO-41 axial-lead package and is not compatible with surface-mount assembly. For SMT equivalents, Microsemi offers the SMAJ4756A and MLL4756A in SMA and SOD-123 packages respectively. These alternatives have different power ratings, thermal characteristics, and impedance values, so direct substitution requires layout and thermal redesign.

What is the maximum steady-state current the 1N4756APE3/TR12 can handle at room temperature?

At TA = 25 °C, the 1N4756APE3/TR12 supports a maximum steady-state regulator current (IZM) of 1500 mA, derived from its 1.0 W power rating and 47 V zener voltage (P = V × I → I = 1.0 W / 47 V ≈ 21.3 mA theoretical, but derated per thermal limits). Actual usable current depends on PCB copper area and ambient temperature - full 1500 mA is only sustainable with proper heatsinking and lead length control per Microsemi's derating curve.

Does the 1N4756APE3/TR12 require dry-pack moisture protection before reflow soldering?

No - the 1N4756APE3/TR12 is moisture sensitivity Level 1 per IPC/JEDEC J-STD-020B, meaning it may be stored indefinitely at ambient conditions without baking or dry-pack requirements. Its plastic encapsulation and UL94V-0 epoxy body provide inherent moisture resistance, eliminating pre-reflow bake cycles and reducing manufacturing overhead.

How does the thermal resistance of the 1N4756APE3/TR12 impact PCB layout?

The 1N4756APE3/TR12 has a junction-to-lead thermal resistance of 45 °C/W at 3/8″ (10 mm) lead length from the body. To avoid exceeding 150 °C junction temperature at 1.0 W dissipation, PCB traces must provide adequate copper area: Microsemi specifies 4 mm² pads with 1 mm wide × 25 mm long tracks for 105 °C/W junction-to-ambient performance. Shorter leads and wider copper pours significantly improve thermal margin.