Microchip Technology 1N4754AP/TR12

Overview

1N4754AP/TR12 from Microsemi is a 1.0 W, 39 V ±5% plastic-encapsulated Zener diode in DO-41 package, rated for 6.5 mA test current, 23 Ω dynamic impedance at I_ZT, and 1000 mA maximum regulator current at T_A = 50°C. It provides stable voltage regulation in power supply reference, overvoltage protection, and biasing circuits across industrial temperature range.

For engineers reviewing the 1N4754AP/TR12 datasheet, 1N4754AP/TR12 pinout, 1N4754AP/TR12 application, or 1N4754AP/TR12 equivalent, key selection factors include its 39 V nominal Zener voltage, 1 W power rating at 25°C with 45°C/W junction-to-lead thermal resistance, DO-41 axial-leaded mechanical form, and RoHS-compliant "e3" plating option (TR12 denotes tape-and-reel packaging).

Technical Context

This discrete Zener diode operates in reverse breakdown to maintain a stable 39 V reference across a wide operating current range (IZK = 0.25 mA to IZM = 1000 mA), with sharp knee characteristics verified by dual-point Zener impedance measurement per MicroNote 202. Its 23 Ω dynamic impedance at 6.5 mA ensures low AC ripple sensitivity in regulation loops.

Designed for through-hole mounting on FR4 PCBs with 1 oz copper, it delivers 1.0 W steady-state dissipation at T_L < 105°C (3/8″ lead length) or T_A < 45°C, with thermal resistance of 105°C/W junction-to-ambient under defined pad layout (4 mm² copper, 1 mm trace width). Polarity is marked by cathode band; regulation requires cathode positive relative to anode.

Key Specifications

Pinout & Package

DO-41 (DO-204AL) plastic axial-leaded package: cylindrical epoxy body, 2.2–2.7 mm diameter, 5.2–7.0 mm length, cathode indicated by black 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 1N4754AP/TR12, 1N4754A offers identical regulation performance but lacks tape-and-reel convenience for production, while MMSZ4702T1G trades power capability and thermal robustness for miniaturization - making 1N4754AP/TR12 optimal for through-hole power reference and clamp roles requiring 1 W dissipation and industrial temperature resilience.

Availability

1N4754AP/TR12 is available at Aetrix Electronics and suitable for power supply reference design, overvoltage protection circuits, and analog bias network stabilization requiring stable component supply and JEDEC-standard compatibility.

Supply support for 1N4754AP/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 developed to deliver JEDEC-standard Zener regulation with enhanced moisture resistance and thermal performance in plastic packages, targeting cost-sensitive yet mission-critical power management applications.

FAQ

What is the Zener voltage tolerance for 1N4754AP/TR12?

The 1N4754AP/TR12 has a nominal Zener voltage of 39 V with a tolerance of ±5%, as indicated by the "A" suffix in the part number per Microsemi's documentation. This tolerance applies at T_L = 25°C and I_ZT = 6.5 mA. The "P" denotes plastic encapsulation and "TR12" specifies tape-and-reel packaging per EIA-296 standard. No additional tolerance modifiers (e.g., "C" for ±2%) are present in this variant.

Can 1N4754AP/TR12 be used in surface-mount designs?

No, the 1N4754AP/TR12 uses a DO-41 axial-leaded package and is designed for through-hole mounting only. For surface-mount equivalents, Microsemi offers the SMAJ4754A and MLL4754A in DO-214AC and SOD-80 packages respectively. Substituting 1N4754AP/TR12 into an SMT layout would require mechanical adaptation and is not recommended due to thermal and mechanical mismatch.

What is the maximum surge current rating for 1N4754AP/TR12?

The 1N4754AP/TR12 has a maximum surge current (I_SM) rating of 1000 mA, measured using a ½ sine-wave pulse of 1/120 second duration at 25°C ambient. This rating applies to short-duration transients such as ESD or inductive kickback. Continuous operation above 1000 mA will cause thermal runaway; proper series limiting resistance must be selected to ensure I_Z remains within safe limits during surge events.

Is 1N4754AP/TR12 RoHS compliant?

Yes, the "e3" suffix in the full manufacturer part number (1N4754AP,e3/TR12) confirms RoHS compliance per EU Directive 2011/65/EU. The device uses annealed matte-tin plating instead of tin-lead, and the void-free thermosetting epoxy body meets UL94V-0 flammability requirements. Aetrix Electronics supplies only RoHS-compliant versions unless otherwise specified.

How does thermal resistance affect PCB layout for 1N4754AP/TR12?

The 1N4754AP/TR12 has a junction-to-lead thermal resistance of 45°C/W and junction-to-ambient resistance of 105°C/W on FR4 with defined copper pads. To sustain 1 W dissipation, PCB traces must provide adequate heat sinking: minimum 4 mm² copper pad area per lead, 1 mm trace width, and 25 mm length. Without this, junction temperature exceeds 150°C, risking parametric shift or failure. Lead length beyond 3/8″ (10 mm) further degrades R_θJL.