Diodes Incorporated 1N4736A-T

Overview

1N4736A-T from Diodes Incorporated is a 1.0 W, 6.8 V ±5% Zener diode in DO-41 glass package, designed for voltage regulation and reference applications with 3.5 Ω zener impedance at 37 mA test current and +0.015 to +0.06 %/°C temperature coefficient. It operates across –65°C to +175°C and supports surge current up to 660 mA (8.3 ms).

For engineers reviewing the 1N4736A-T datasheet, 1N4736A-T pinout, 1N4736A-T application, or 1N4736A-T equivalent, key selection factors include nominal zener voltage tolerance, thermal resistance (175 °C/W), forward voltage (1.2 V @ 200 mA), zener impedance stability, and RoHS-compliant Sn96.5Ag3.5 termination.

Technical Context

This discrete Zener diode functions as a precision shunt voltage regulator by maintaining a stable 6.8 V reverse breakdown voltage under controlled test current (IZT = 37 mA). Its low dynamic impedance (3.5 Ω) and tight voltage tolerance (±5%) enable accurate voltage clamping in power supply feedback paths and reference circuits.

The device uses a glass-passivated DO-41 package with cathode band polarity marking and achieves thermal equilibrium via lead-length-dependent junction-to-ambient thermal resistance (175 °C/W at TL = 50°C, 9.5 mm lead length). It exhibits a positive temperature coefficient (+0.015 to +0.06 %/°C), indicating increasing VZ with rising temperature.

Key Specifications

Pinout & Package

Package: DO-41 glass case with axial leads, UL 94V-0 flammability rating, cathode identified by painted band, weight ≈ 0.35 g.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener voltage regulation applications.

Compared with DFLZ6.8-7 and 1N4736A-A, the 1N4736A-T offers superior power handling (1.0 W vs. 0.5 W) and lower dynamic impedance (3.5 Ω vs. 10 Ω), making it preferred for legacy through-hole designs requiring robust regulation under variable load conditions.

Availability

1N4736A-T is available at Aetrix Electronics and suitable for industrial power supplies, overvoltage protection circuits, programmable reference sources, and temperature-compensated bias generators requiring stable component supply and long-lifecycle support.

Supply support for 1N4736A-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' standard Zener diode product line, engineered for general-purpose voltage regulation and reference applications where cost, consistency, and broad voltage coverage (3.3 V to 75 V) are critical.

FAQ

What is the maximum continuous power dissipation for 1N4736A-T at 70°C ambient?

At 70°C ambient, the 1N4736A-T must be derated linearly from its 1.0 W rating at 25°C using the 6.67 mW/°C derating factor. The allowable power is 1.0 W − (6.67 mW/°C × 45°C) = 699.85 mW. This assumes leads are held at 50°C with 9.5 mm length per datasheet Note 1.

How does the +0.015 to +0.06 %/°C temperature coefficient affect circuit accuracy?

This positive coefficient means VZ increases with temperature: over a 100°C range, VZ shifts by +0.68 V to +4.08 V (0.015–0.06% of 6.8 V × 100). In precision references, this requires compensation via complementary TC components or calibration at multiple temperatures.

Can 1N4736A-T replace 1N4736A-A in a design?

Yes-1N4736A-T and 1N4736A-A share identical electrical, thermal, and mechanical specifications. The only difference is packaging: tape-and-reel (T) versus ammo pack (A). No circuit redesign or qualification is needed when substituting between them.

Why is 1N4736A-T marked "Not Recommended for New Design"?

Diodes Incorporated recommends DFLZxx series for new designs due to surface-mount compatibility, smaller footprint, and improved manufacturability. The 1N4736A-T remains fully qualified and supported for legacy through-hole systems and repair/replacement programs.