onsemi 1N5996B_T50R

Overview

1N5996B_T50R from Fairchild Semiconductor is a 5.89–6.51 V, 5% tolerance, 500 mW DO-35 glass-case Zener diode optimized for precision voltage regulation and reference applications in low-power analog circuits, power supply feedback loops, and overvoltage protection stages. It delivers 6.46 V nominal Zener voltage at 5 mA test current with 8 Ω dynamic impedance and 1 mA leakage current at 5.2 V reverse bias.

For engineers reviewing the 1N5996B_T50R datasheet, pinout, applications, or equivalent options, this page provides verified electrical parameters, thermal derating behavior, cathode identification guidance, and direct-fit alternatives for voltage reference design, BOM replacement, and legacy component sourcing.

Technical Context

This Zener diode operates in reverse breakdown mode with tightly controlled voltage tolerance (±5%) and low dynamic impedance (8 Ω @ I_Z = 5 mA), enabling stable reference generation under varying load and temperature conditions. Its 500 mW power rating at T_L ≤ 75°C and 4.0 mW/°C linear derating support reliable operation in compact PCB layouts with short lead lengths.

The device features a DO-35 axial glass package with cathode band marking, rated for -65°C to +200°C operating and storage temperatures. Leakage current remains ≤1 mA up to 5.2 V reverse voltage, ensuring minimal quiescent power loss in high-impedance bias networks.

Key Specifications

Pinout & Package

DO-35 glass axial package with cathode identified by a single color band on the body. Leads are tinned copper-clad steel; case diameter is 1.8 mm, length is 4.2 mm, lead diameter is 0.45 mm. No polarity-sensitive mounting orientation beyond cathode band alignment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5996B_T50R, 1N5233B offers marginally lower regulation voltage and higher impedance, while BZX55-C6V2 trades tighter leakage for reduced AC regulation fidelity-both require verification of V_Z tolerance stack-up in closed-loop systems.

Availability

1N5996B_T50R is available at Aetrix Electronics and suitable for switch-mode power supply feedback, overvoltage protection clamp, and temperature-stable reference source applications requiring stable component supply, long-lifecycle support, and traceable sourcing for industrial and automotive programs.

Supply support for 1N5996B_T50R 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 company specializing in power management, analog, and discrete devices before its acquisition by ON Semiconductor in 2016. Its legacy Zener diode portfolio emphasizes reliability and precision in industrial and automotive environments.

The 1N5996B_T50R belongs to Fairchild's 1N5985B–1N6025B family of general-purpose Zener diodes designed for voltage regulation, reference, and protection in cost-sensitive, high-volume applications with demanding thermal and longevity requirements.

FAQ

What is the nominal Zener voltage and tolerance of the 1N5996B_T50R?

The 1N5996B_T50R has a nominal Zener voltage of 6.46 V with a guaranteed tolerance of ±5%, resulting in a minimum V_Z of 5.89 V and maximum of 6.51 V at 5 mA test current. This specification is measured under thermal equilibrium at lead temperature of 30°C ± 1°C with 3/8″ lead length, per Fairchild's Rev. C2 datasheet. The 1N5996B_T50R maintains this tolerance across its full operating temperature range.

What is the maximum power dissipation and thermal derating behavior of the 1N5996B_T50R?

The 1N5996B_T50R is rated for 500 mW power dissipation at lead temperature (T_L) ≤ 75°C with 3/8″ lead length. Above 75°C, it derates linearly at 4.0 mW/°C. This means at 100°C lead temperature, maximum allowable power drops to 400 mW. The 1N5996B_T50R's DO-35 package relies on lead conduction for heat transfer, so PCB layout and lead length directly impact thermal performance.

How is cathode polarity marked on the 1N5996B_T50R package?

The cathode of the 1N5996B_T50R is marked by a single color band on the glass body of the DO-35 axial package. This band must be aligned toward the higher-potential node in Zener operation (i.e., connected to the regulated output). The anode is the unmarked end. The 1N5996B_T50R follows Fairchild's standard top-marking convention: "F" logo, "99", then "6B" - confirming its identity within the 1N5995B–1N5999B subgroup.

What is the Zener impedance and leakage current specification for the 1N5996B_T50R?

The 1N5996B_T50R exhibits 8 Ω dynamic impedance (Z_Z) at I_Z = 5 mA and 1 mA leakage current (I_R) at V_R = 5.2 V. These values are confirmed in the Electrical Characteristics table of the Fairchild datasheet. The low impedance ensures minimal output voltage deviation under load transients, while the specified leakage defines the upper bound of reverse-bias current in high-impedance reference networks.

Can the 1N5996B_T50R be used in place of other Zener diodes in the 1N5995B–1N5999B series?

No - the 1N5996B_T50R is not interchangeable with adjacent members like 1N5995B (5.89–6.51 V) or 1N5997B (7.125–7.875 V) due to non-overlapping Zener voltage ranges. Each part in the 1N5995B–1N5999B series has distinct V_Z min/max values and test currents. Substituting the 1N5996B_T50R requires verifying that 6.46 V nominal regulation meets system-level accuracy, headroom, and thermal constraints - the 1N5996B_T50R must be selected based on its exact voltage band, not family proximity.