Diodes Incorporated 1N4734A-T

Overview

1N4734A-T from Diodes Incorporated is a 1.0W, 5.6V ±5% Zener diode in DO-41 glass package, designed for voltage regulation and reference applications with 5.0Ω zener impedance at 45mA test current and -65°C to +175°C operating temperature range. It delivers stable 5.6V clamping in power supply feedback loops, overvoltage protection circuits, and precision reference sources.

For engineers reviewing the 1N4734A-T datasheet, 1N4734A-T pinout, 1N4734A-T application, or 1N4734A-T equivalent, key selection criteria include nominal zener voltage (5.6V), power dissipation (1.0W), zener impedance (5.0Ω @ 45mA), reverse leakage (10µA @ 2.0V), and thermal resistance (175°C/W).

Technical Context

This discrete Zener diode operates in reverse breakdown to maintain a stable 5.6V reference across load and line variations. Its 5.0Ω dynamic impedance ensures minimal output voltage deviation under changing current conditions, while the 1.0W power rating supports sustained regulation in low-to-medium current applications.

The DO-41 glass package provides hermetic sealing and UL 94V-0 flammability compliance. Cathode band polarity marking and Sn96.5Ag3.5 lead finish ensure reliable soldering per MIL-STD-202 Method 208, with thermal derating starting above 50°C at 6.67mW/°C.

Key Specifications

Pinout & Package

DO-41 glass axial package with cathode band marking; two-terminal device with no internal circuitry - anode and cathode terminals only.

Key Features

Applications

Availability

1N4734A-T is available at Aetrix Electronics and suitable for switch-mode power supplies, microcontroller reset circuits, industrial sensor signal conditioning, and overvoltage protection clamps requiring stable component supply and long-term obsolescence mitigation support.

Supply support for 1N4734A-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, serving industrial, computing, communications, and consumer markets with high-reliability components.

The 1N47xxA series belongs to Diodes' legacy Zener diode product line, engineered specifically for cost-sensitive, high-volume voltage reference and regulation applications where DO-41 packaging and ±5% tolerance meet mainstream design requirements.

FAQ

What is the maximum continuous Zener current for 1N4734A-T at 25°C?

The maximum continuous Zener current is calculated as P_D/V_Z = 1.0W / 5.6V ≈ 178.6mA. However, the rated test current is 45mA, and operation above this level requires thermal derating per the 6.67mW/°C curve. Sustained operation beyond 100mA risks exceeding junction temperature limits without heatsinking.

Is 1N4734A-T compatible with lead-free reflow soldering processes?

Yes - the Sn96.5Ag3.5 lead finish is qualified for lead-free reflow per J-STD-020, with peak temperatures up to 260°C. The DO-41 glass body withstands thermal shock, and the device meets MIL-STD-202 Method 208 solderability requirements. No special pre-bake is required.

Does 1N4734A-T have a specified temperature coefficient?

Yes - its temperature coefficient is 0 to +0.045%/°C at I_ZT = 45mA. This positive, low-drift characteristic makes it suitable for applications where output voltage must increase slightly with temperature to compensate for other component drift.

Can 1N4734A-T replace 1N4733A or 1N4735A in existing designs?

Direct substitution is possible only if the 5.6V nominal voltage meets system requirements - 1N4733A (5.1V) and 1N4735A (6.2V) differ by ≥10% in V_Z. Electrical differences include higher Z_ZT (7.0Ω vs. 5.0Ω) for 1N4733A and lower Z_ZT (2.0Ω vs. 5.0Ω) for 1N4735A, affecting regulation accuracy under dynamic loads.