onsemi 1N754A_T50R

Overview

1N754A_T50R from Fairchild Semiconductor is a 6.2 V, ±5% tolerance silicon Zener diode in DO-35 glass package, rated for 500 mW power dissipation at ≤75°C, with 5 Ω dynamic impedance at 20 mA and 0.1 µA reverse leakage at 1 V, used for precision voltage regulation in low-power analog reference circuits.

For engineers reviewing the 1N754A_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, thermal derating behavior, cathode-band polarity marking, and DO-35 lead-form compatibility with through-hole PCB layouts.

Technical Context

This device operates as a two-terminal voltage reference diode, conducting in reverse breakdown to maintain stable output voltage across varying load currents. Its 6.2 V nominal zener voltage is specified at 20 mA test current, with tight 5% tolerance and low 5 Ω dynamic impedance ensuring minimal regulation deviation under small-signal load shifts.

The DO-35 glass package supports operation from –65°C to +200°C, with power derating beginning at 75°C (4.0 mW/°C), and features a visible cathode band for unambiguous polarity identification during manual assembly or automated optical inspection.

Key Specifications

Pinout & Package

DO-35 glass axial package with cathode identified by a single dark band on the body; leads are unmarked anode/cathode terminals - cathode band denotes the P-side (higher potential terminal during reverse bias operation).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N754A_T50R, the 1N4735A offers higher power margin in a larger package, while the BZX55C6V2 provides identical DO-35 fit-and-function with alternate supply chain provenance-neither is pin-compatible in the strict sense (Zener diodes have no pins), but both share identical terminal polarity and mounting geometry.

Availability

1N754A_T50R is available at Aetrix Electronics and suitable for precision voltage reference, overvoltage protection, sensor biasing, and reset threshold generation requiring stable component supply and long-lifecycle support.

Supply support for 1N754A_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, signal conditioning, and discrete components before its acquisition by ON Semiconductor in 2016.

The 1N754A_T50R belongs to Fairchild's legacy 1N7xxA Zener diode family, designed for general-purpose voltage regulation and clamping in cost-sensitive, high-reliability analog circuits.

FAQ

What is the nominal zener voltage and tolerance of the 1N754A_T50R?

The 1N754A_T50R has a nominal zener voltage of 6.2 V with a ±5% tolerance, meaning its actual breakdown voltage falls between 5.89 V and 6.51 V at 20 mA test current and 25°C ambient. This tolerance is guaranteed per device and verified during production testing. The 1N754A_T50R maintains this specification across its full operating temperature range when applied within its power derating limits.

What package type and marking does the 1N754A_T50R use?

The 1N754A_T50R uses a DO-35 glass axial package with a visible cathode band. Its top marking consists of three lines: "F" (Fairchild logo), "54" (device identifier), and "A" (suffix denoting 5% tolerance). The cathode band aligns with the "A" marking line and must be oriented toward the higher-potential node in circuit layout. The 1N754A_T50R follows standard DO-35 mechanical dimensions and lead spacing for through-hole insertion.

What is the maximum power dissipation and thermal derating behavior of the 1N754A_T50R?

The 1N754A_T50R is rated for 500 mW power dissipation at lead temperature ≤75°C with 3/8″ lead length. Above 75°C, it derates linearly at 4.0 mW/°C, reaching zero dissipation at 200°C junction temperature. This derating curve ensures safe operation in elevated ambient environments when mounted with appropriate thermal relief. The 1N754A_T50R's glass package contributes to stable long-term performance under these thermal conditions.

How does the dynamic impedance of the 1N754A_T50R affect regulation performance?

The 1N754A_T50R exhibits 5 Ω dynamic impedance at 20 mA, meaning a 1 mA change in zener current produces approximately 5 mV change in regulated voltage. This low Z_Z enables tight voltage control in low-noise analog references and improves rejection of input ripple. In practice, the 1N754A_T50R delivers better regulation stability than higher-Z_Z Zeners like the 1N753A (7 Ω) or 1N755A (6 Ω) under identical load variations.

Can the 1N754A_T50R be used as a replacement for other 6.2 V Zener diodes?

The 1N754A_T50R can serve as a functional alternative to other 6.2 V, ±5%, DO-35 Zeners such as the BZX55C6V2 or 1N4735A (with package adaptation), provided voltage tolerance, dynamic impedance, and power rating meet design requirements. It is not a drop-in replacement for non-DO-35 packages or different tolerance grades. Always verify thermal margin and leakage current in the target application before substituting the 1N754A_T50R.