Microchip Technology 1N4757P/TR12

Overview

1N4757P/TR12 from Microsemi is a 1.0 W axial-lead silicon Zener diode with a nominal Zener voltage of 51 V ±5%, 5.0 mA test current, 95 Ω dynamic impedance at I_ZT, and maximum reverse current of 5 μA at 38.8 V. It operates from –65 °C to +150 °C and is used for precision voltage regulation in power supply reference circuits.

For engineers reviewing the 1N4757P/TR12 datasheet, 1N4757P/TR12 pinout, 1N4757P/TR12 application, or 1N4757P/TR12 equivalent, key selection criteria include Zener voltage tolerance, thermal resistance (45 °C/W junction-to-lead), surge current rating (1500 mA), RoHS-compliant "e3" plating, and DO-41 package compatibility with standard axial-lead PCB layouts.

Technical Context

This device functions as a two-terminal shunt voltage regulator, maintaining stable output voltage across wide operating current ranges (IZK = 0.25 mA to IZM = 90 mA) by exploiting controlled reverse breakdown. Its 51 V nominal Zener voltage places it in the medium-voltage regulation range where temperature coefficient is near zero crossing (~0 mV/°C), minimizing drift over temperature.

The DO-41 plastic package provides moisture sensitivity Level 1 per J-STD-020B, eliminating dry-pack requirements, while its 45 °C/W junction-to-lead thermal resistance enables reliable 1.0 W dissipation at TL ≤ 105 °C with 3/8″ lead length - critical for high-reliability linear regulator and overvoltage clamp designs.

Key Specifications

Pinout & Package

1N4757P/TR12 uses the DO-41 (JEDEC DO-204AL) axial-lead plastic package with cathode indicated by a band. Leads are tin-lead or RoHS-compliant matte-tin plated, 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 1N4757A and MMBZ5257BS, the 1N4757P/TR12 offers superior thermal performance in axial-lead form, full 1 W continuous dissipation capability, and industry-standard surge immunity - making it the preferred choice for industrial power regulation and ruggedized overvoltage protection.

Availability

1N4757P/TR12 is available at Aetrix Electronics and suitable for industrial power supplies, sensor interface modules, and calibration equipment requiring stable component supply with RoHS compliance and tape-and-reel packaging.

Supply support for 1N4757P/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 and mixed-signal components for aerospace, defense, and industrial markets.

The 1N47xxAP series was designed specifically for precision voltage regulation in mission-critical power systems where long-term stability, wide temperature operation, and surge resilience are mandatory.

FAQ

What is the Zener voltage tolerance for 1N4757P/TR12?

The 1N4757P/TR12 has a nominal Zener voltage of 51 V with a tolerance of ±5%, as indicated by the "A" suffix in the JEDEC part number. This means the actual measured V_Z at I_ZT = 5.0 mA falls between 48.45 V and 53.55 V at 25 °C. The tolerance is guaranteed across the full operating temperature range and is verified per JEDEC test methods.

Does 1N4757P/TR12 require dry packing before PCB assembly?

No, 1N4757P/TR12 does not require dry packing. It is moisture sensitivity Level 1 per IPC/JEDEC J-STD-020B, meaning it can be stored and assembled without baking or humidity-controlled environments. This simplifies logistics and eliminates risk of popcorning during reflow, even when used alongside moisture-sensitive surface-mount components on the same board.

What is the maximum steady-state power dissipation for 1N4757P/TR12?

The maximum steady-state power dissipation for 1N4757P/TR12 is 1.0 W at lead temperature (T_L) ≤ 105 °C with 3/8″ (10 mm) lead length from the body. When mounted on FR4 with 1 oz Cu and specified copper pad geometry, derating begins above 45 °C ambient - full 1 W is only sustainable below that ambient temperature unless heatsinking is added.

Can 1N4757P/TR12 be used as a replacement for 1N4757A?

Yes, 1N4757P/TR12 is functionally equivalent to 1N4757A in electrical parameters but differs mechanically: the "P" suffix denotes DO-41 plastic construction versus DO-35 glass for the "A" version. The 1N4757P/TR12 offers lower thermal resistance (45 °C/W vs. 105 °C/W), improved mechanical ruggedness, and RoHS-compliant "e3" plating - making it a direct upgrade where board layout accommodates the larger DO-41 footprint.

What does the "TR12" suffix indicate in 1N4757P/TR12?

The "TR12" suffix in 1N4757P/TR12 indicates tape-and-reel packaging per EIA-296 standard, with 12,000 units per reel. This format supports automated pick-and-place assembly and ensures consistent orientation (cathode band aligned) for high-volume manufacturing. The "TR" designation is optional and does not affect electrical or thermal specifications of the 1N4757P/TR12 device itself.