Microchip Technology 1N4755AP/TR12

Overview

1N4755AP/TR12 from Microsemi is a 1.0 W, 43 V ±5% plastic-encapsulated Zener diode in DO-41 package, designed for precision voltage regulation in power supply feedback loops, reference circuits, and overvoltage protection. It delivers stable Zener voltage at 6.0 mA test current, with dynamic impedance of 70 Ω, maximum reverse current of 5 μA at 32.7 V, and operates from –65°C to +150°C.

For engineers reviewing the 1N4755AP/TR12 datasheet, 1N4755AP/TR12 pinout, 1N4755AP/TR12 application, or 1N4755AP/TR12 equivalent, key selection criteria include Zener voltage tolerance (±5%), thermal resistance (45°C/W junction-to-lead), surge current rating (1500 mA), RoHS-compliant "e3" plating, and tape-and-reel packaging (TR12).

Technical Context

This axial-lead Zener diode operates in reverse breakdown mode to maintain a stable 43 V reference across a wide current range (1–110 mA). Its low dynamic impedance (70 Ω at 6.0 mA) ensures minimal voltage variation under load transients, while its 1.0 W power rating supports continuous regulation without external heatsinking at lead temperatures below 105°C.

The device features a cathode band marking, tin-lead or matte-tin plating per MIL-STD-750, and moisture sensitivity level 1 per J-STD-020B-eliminating dry-pack requirements. It is not ESD-sensitive per MIL-STD-750 Method 1020 and meets UL94V-0 flammability standards.

Key Specifications

Pinout & Package

Package: DO-41 (DO-204AL), axial-lead, plastic-encapsulated, void-free thermosetting epoxy body (UL94V-0). Cathode identified by color band.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N4755A and MMBZ5265BS-7-F, the 1N4755AP/TR12 uniquely combines 1 W power capability, DO-41 mechanical robustness, TR12 automation readiness, and full industrial temperature range-making it optimal for production-grade power management where reliability and manufacturability are co-prioritized.

Availability

1N4755AP/TR12 is available at Aetrix Electronics and suitable for switch-mode power supplies, industrial sensor references, overvoltage clamp protection, and programmable threshold detection requiring stable component supply and long-term obsolescence mitigation.

Supply support for 1N4755AP/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 engineered for ruggedized voltage regulation in mission-critical power systems-emphasizing thermal stability, surge resilience, and JEDEC-standard interoperability across military and commercial applications.

FAQ

What is the Zener voltage tolerance of the 1N4755AP/TR12?

The 1N4755AP/TR12 has a Zener voltage tolerance of ±5%, as indicated by the "A" suffix in its part number. This means its nominal 43 V Zener voltage is guaranteed between 40.85 V and 45.15 V at 6.0 mA test current and 25°C lead temperature. The tolerance remains valid across its full operating temperature range of –65°C to +150°C, supporting stable regulation in harsh environments.

Does the 1N4755AP/TR12 require dry-pack moisture protection before PCB assembly?

No, the 1N4755AP/TR12 does not require dry-pack moisture protection. It is rated at Moisture Sensitivity Level 1 per IPC/JEDEC J-STD-020B, meaning it can be stored indefinitely at ambient conditions (<30°C/60% RH) without baking or dry storage. This eliminates pre-reflow baking steps and simplifies manufacturing logistics for high-mix production lines.

What is the maximum steady-state current the 1N4755AP/TR12 can regulate continuously?

The 1N4755AP/TR12 supports a maximum steady-state Zener current (I_ZM) of 110 mA at T_L = 50°C, derived from its 1.0 W power rating and 43 V Zener voltage. At 25°C ambient on FR4 with 4 mm² copper pads, derating reduces usable current to ~70 mA. Exceeding these limits risks thermal runaway; proper lead length (≥10 mm) and copper area must be maintained to sustain 1 W dissipation.

Is the 1N4755AP/TR12 RoHS compliant?

Yes, the 1N4755AP/TR12 is RoHS compliant, as confirmed by the "e3" suffix in its full manufacturer designation. It uses annealed matte-tin plating per MIL-STD-750 Method 2026 and complies with EU Directive 2011/65/EU. Lead content is below 1000 ppm, and all six restricted substances meet applicable thresholds for industrial electronics applications.

Can the 1N4755AP/TR12 replace a glass-body 1N4755G in an existing design?

The 1N4755AP/TR12 can replace 1N4755G in most applications, but thermal design must be re-evaluated. While both share identical electrical specs (43 V, ±5%, 1 W), the plastic "P" variant has lower junction-to-lead thermal resistance (45°C/W vs. ~60°C/W for glass), improving heat transfer through leads-but reduced junction-to-ambient performance on PCBs due to lower thermal mass. Verify temperature rise under worst-case load.