onsemi 1N5996B

Overview

1N5996B from Fairchild Semiconductor is a 5.0% tolerance, 6.46 V nominal Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 4.0 mW/°C derating, designed for precision voltage reference and overvoltage protection in low-power analog circuits.

For engineers reviewing the 1N5996B datasheet, pinout, applications, or equivalent options, key selection criteria include its 6.46 V ±5% Zener voltage at 5 mA test current, 8 Ω dynamic impedance at IZ, 1 mA leakage current at 5.2 V reverse bias, and 74 mA maximum Zener current - all critical for stable regulation in space-constrained linear power supplies and sensor biasing networks.

Technical Context

The 1N5996B operates as a two-terminal voltage reference device with sharp Zener breakdown at 6.46 V, exhibiting low dynamic impedance (8 Ω @ 5 mA) and tightly controlled tolerance (±5%) to maintain regulation accuracy across temperature and load variations. Its DO-35 glass package enables reliable thermal conduction through 3/8″ leads while supporting operation from −65°C to +200°C.

It delivers stable reference performance under DC bias conditions with 1 mA leakage current at 5.2 V reverse voltage and forward voltage ≤1.2 V at 200 mA, making it suitable for bidirectional clamping and precision shunt regulation where low noise and repeatable knee characteristics are required.

Key Specifications

Pinout & Package

DO-35 glass axial package with cathode indicated by color band; two-terminal device requiring no external biasing - anode and cathode terminals defined solely by physical orientation and marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5996B, the 1N4735A offers higher power capacity but requires layout adaptation, while the BZX55C6V2 matches the DO-35 form factor and improves leakage by three orders of magnitude - making it superior for precision analog front-ends despite its 0.26 V lower nominal voltage.

Availability

1N5996B is available at Aetrix Electronics and suitable for low-power voltage reference, overvoltage clamp protection, and linear power supply regulation requiring stable component supply and long-term obsolescence management.

Supply support for 1N5996B 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

Fairchild Semiconductor was a U.S.-based semiconductor manufacturer specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016; its legacy product lines remain widely deployed in industrial and automotive systems.

The 1N5996B belongs to Fairchild's 1N5985B–1N6025B Zener diode family, engineered for general-purpose voltage regulation and transient suppression in cost-sensitive, space-constrained applications where reliability across wide temperature ranges is essential.

FAQ

What is the Zener voltage tolerance of the 1N5996B?

The 1N5996B has a Zener voltage tolerance of ±5%, meaning its actual breakdown voltage falls between 6.137 V and 6.783 V when measured at 5 mA test current and 25°C ambient. This tolerance is guaranteed across the full operating temperature range and is integral to the device's qualification for use in production-grade voltage reference circuits without post-manufacturing sorting.

What is the maximum Zener current rating for the 1N5996B?

The 1N5996B has a maximum Zener current (I_ZM) of 74 mA at 25°C, derived from its 500 mW power rating and nominal 6.46 V Zener voltage. This value decreases linearly above 75°C ambient due to the 4.0 mW/°C derating factor, reaching approximately 54 mA at 125°C case temperature - a critical limit for sustained shunt regulation design.

Does the 1N5996B have a specified forward voltage?

Yes, the 1N5996B specifies a maximum forward voltage (V_F) of 1.2 V at 200 mA forward current, consistent with standard silicon diode behavior. This parameter is relevant for applications using the device in bidirectional clamping configurations or when evaluating conduction losses during positive half-cycle transients.

What package type does the 1N5996B use, and how is polarity marked?

The 1N5996B uses the DO-35 glass axial package with cathode identified by a single color band near one end of the glass body. The anode is the unmarked lead; correct orientation is essential for proper Zener operation, as reverse bias must be applied across the cathode-to-anode terminals to achieve regulation.

How does the 1N5996B's Zener impedance affect regulation performance?

The 1N5996B exhibits a Zener impedance (Z_Z) of 8 Ω at 5 mA test current, which directly determines how much its output voltage varies with changes in Zener current. For example, a 10 mA load step induces only ~80 mV shift in regulated voltage - a key advantage over higher-impedance alternatives when driving variable loads in precision analog circuits.