Diodes Incorporated 1N4755A-T

Overview

1N4755A-T from Diodes Incorporated is a 1.0 W, 43 V ±5% Zener diode in DO-41 glass package, designed for precision voltage regulation and overvoltage protection in DC power rails. It delivers 6.0 mA test current, 70 Ω dynamic impedance at I_ZT, and operates across –65°C to +175°C with cathode-band polarity marking. Used in feedback loops of linear regulators and clamp circuits for industrial power supplies.

For engineers reviewing the 1N4755A-T datasheet, 1N4755A-T pinout, 1N4755A-T application, or 1N4755A-T equivalent, key selection criteria include nominal Zener voltage (43 V), power dissipation (1.0 W), Zener impedance (70 Ω @ 6.0 mA), temperature coefficient (+0.06 to +0.095 %/°C), and DO-41 mechanical compatibility with through-hole PCB assembly.

Technical Context

This Zener diode operates in reverse breakdown mode with sharp knee characteristics verified by dual-point impedance measurement (IZT and IZK). Its 70 Ω Zener impedance at 6.0 mA and 1500 Ω at 0.25 mA ensures stable regulation under varying load conditions.

Thermal performance is defined by 175 °C/W junction-to-ambient resistance at TA = 25°C, derating linearly at 6.67 mW/°C above 50°C when leads are held at 50°C with 9.5 mm length. The DO-41 glass package supports UL 94V-0 flammability rating and Sn96.5Ag3.5 solderable terminations.

Key Specifications

Pinout & Package

DO-41 glass axial package with cathode band marking; two-terminal device with no internal circuitry. Polarity is unambiguous: banded end is cathode, non-banded end is anode.

Key Features

Applications

Availability

1N4755A-T is available at Aetrix Electronics and suitable for DC power supply regulation, overvoltage clamp circuits, and industrial control feedback loops requiring stable component supply and long-term obsolescence mitigation planning.

Supply support for 1N4755A-T 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management and signal integrity solutions for industrial and automotive markets.

The 1N47xxA series belongs to Diodes' legacy Zener diode product line, engineered for cost-effective, thermally robust voltage reference and protection in through-hole power systems.

FAQ

What is the maximum continuous Zener current for 1N4755A-T at 25°C?

The maximum continuous Zener current is calculated as P_d/V_Z = 1.0 W / 43 V ≈ 23.3 mA. However, the rated test current is 6.0 mA, and operation above this value requires thermal derating per the 6.67 mW/°C curve above 50°C ambient.

Is 1N4755A-T RoHS compliant?

Yes - it features a lead-free Sn96.5Ag3.5 termination and complies with EU Directive 2002/95/EC (RoHS), with applicable exemptions for glass encapsulation and high-temperature soldering noted in Annexes 5 and 7.

How does the temperature coefficient affect regulation accuracy over temperature?

With a TC of +0.06 to +0.095 %/°C, V_Z increases by 25.8–40.8 mV/°C. Over a 100°C range (–25°C to +75°C), total drift is +2.58 V to +4.08 V - critical for high-precision references but acceptable for general-purpose clamping.

Can 1N4755A-T replace 1N4755A-A in the same PCB footprint?

Yes - both share identical DO-41 glass package dimensions, polarity marking, and electrical specifications. The "-T" suffix denotes tape-and-reel packaging; "-A" is ammo pack. Mechanical fit and soldering behavior are fully interchangeable.