Diodes Incorporated 1N4751A-T

Overview

1N4751A-T from Diodes Incorporated is a 1.0W, 30V nominal Zener diode in DO-41 glass package with ±5% voltage tolerance, 40Ω maximum Zener impedance at 8.5mA test current, and 150mA maximum surge current (8.3ms). It provides precision voltage regulation in low-power analog reference and overvoltage protection circuits.

For engineers reviewing the 1N4751A-T datasheet, 1N4751A-T pinout, 1N4751A-T application, or 1N4751A-T equivalent, key selection criteria include Zener voltage stability over temperature (0.06–0.095%/°C), thermal resistance (175°C/W), reverse leakage (<5µA at 22.8V), and DO-41 mechanical compatibility with through-hole PCB layouts.

Technical Context

This discrete Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying load and temperature conditions. Its 30V nominal Zener voltage is specified at 8.5mA test current (IZT), with sharp knee characteristics verified by dual-point Zener impedance measurement per JEDEC standards.

The device uses a glass-passivated DO-41 package with Sn96.5Ag3.5 terminations, rated for -65°C to +175°C operating temperature and 1.0W power dissipation at 25°C ambient. Derating begins above 50°C at 6.67mW/°C when leads are held at 50°C with 9.5mm length from case.

Key Specifications

Pinout & Package

DO-41 glass axial-leaded package with cathode band marking; total weight ≈0.35 g; UL 94V-0 flammability rating; Sn96.5Ag3.5 solderable terminations.

Key Features

Applications

Availability

1N4751A-T is available at Aetrix Electronics and suitable for power supply reference, overvoltage clamp, and signal level translation applications requiring stable component supply and long-term obsolescence management support.

Supply support for 1N4751A-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 components for industrial, computing, and consumer markets.

The 1N47xxA series belongs to Diodes' legacy Zener diode product line, designed specifically for general-purpose voltage regulation and protection in cost-sensitive, through-hole assembled systems.

FAQ

What is the maximum steady-state power dissipation for 1N4751A-T at 70°C ambient?

At 70°C ambient, the 1N4751A-T must be derated from its 1.0W rating at 25°C. With a derating factor of 6.67mW/°C above 50°C, power dissipation is reduced to 1.0W − (20°C × 6.67mW/°C) = 866.6mW. This assumes leads are maintained at 50°C with 9.5mm length from case per datasheet Note 1.

How does the Zener impedance of 40Ω affect regulation performance?

A 40Ω Zener impedance means that for every 1mA change in Zener current, the output voltage shifts by approximately 40mV. This value reflects regulation stiffness under small-signal AC conditions and directly impacts ripple rejection in reference circuits-lower ZZT yields tighter voltage control under dynamic loads.

Is 1N4751A-T compatible with lead-free reflow soldering processes?

No-1N4751A-T uses Sn96.5Ag3.5 terminations and is intended for wave or hand soldering per MIL-STD-202 Method 208. Its glass DO-41 package is not rated for peak reflow temperatures (>235°C); exposure to lead-free reflow profiles risks internal cracking or seal failure.

Why is there no listed alternative part for 1N4751A-T?

Per Diodes Incorporated's official documentation (DS18007 Rev. 20-4), the entire 1N4728A–1N4761A series-including 1N4751A-T-is marked "OBSOLETE – PART DISCONTINUED" with "NO ALTERNATE PART" stated explicitly. No functional replacement has been designated by the manufacturer.