onsemi 1N5946BG

Overview

1N5946BG from onsemi is a 3 W, 75 V ±5% Zener diode in DO-41 axial package, designed for precision voltage regulation and overvoltage protection in DC power supplies, reference circuits, and surge-clamping applications. It delivers 56 A maximum DC zener current, 5.0 Ω typical zener impedance at 140 mA test current, and operates across −65°C to +200°C junction temperature range.

For engineers reviewing the 1N5946BG datasheet, pinout, applications, or equivalent options, this device serves as a high-reliability, Pb-free Zener regulator with Class 3 ESD rating (>16 kV HBM), 98 W surge capability (1 ms), and guaranteed limits on six electrical parameters - critical for industrial power conditioning and voltage reference stability.

Technical Context

The 1N5946BG uses silicon-oxide passivated junction technology to achieve stable reverse breakdown characteristics and low leakage (<0.25 μA at 56 V). Its thermal design centers on lead-to-junction conduction, with transient thermal resistance θ_JL dependent on pulse width and duty cycle per Figure 2.

It is rated for 3 W steady-state dissipation at 75°C lead temperature (3/8″ lead length), derating linearly to zero at 125°C. The 75 V nominal zener voltage exhibits a positive temperature coefficient (~6.5 mV/°C) per Figure 6, making it suitable for temperature-compensated reference designs when paired with negative-coefficient devices.

Key Specifications

Pinout & Package

Package: DO-41 (Case 59-10), axial-leaded, void-free thermosetting plastic. Cathode indicated by polarity band; anode is unmarked lead. Mounting position unrestricted.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5946BG, the 1N5946BRLG offers identical performance with packaging optimized for automation, while BZX85C75 trades power capability and regulation precision for lower cost in non-demanding applications - making 1N5946BG the preferred choice for industrial-grade 75 V regulation where reliability and thermal margin are critical.

Availability

1N5946BG is available at Aetrix Electronics and suitable for industrial power supplies, analog reference subsystems, and ruggedized I/O protection circuits requiring stable component supply and full traceability.

Supply support for 1N5946BG 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 1N5913B Series is part of onsemi's legacy Zener regulator portfolio, engineered for high-reliability voltage stabilization in harsh environments - emphasizing robust surge handling, wide temperature operation, and guaranteed parametric limits.

FAQ

What is the exact Zener voltage tolerance for 1N5946BG?

The 1N5946BG has a guaranteed ±5% Zener voltage tolerance, with nominal 75 V specified as 71.25 V (min) to 78.75 V (max) at 140 mA test current (I_ZT). This tolerance is confirmed in the Electrical Characteristics table on page 3 of the official onsemi datasheet Rev. 9 (July 2024), and applies across the full operating temperature range.

Can 1N5946BG be used in surface-mount designs?

No - the 1N5946BG is strictly an axial-leaded DO-41 device and is not suitable for direct SMT placement. While its leads can be formed for through-hole mounting on SMT boards, it lacks gull-wing, J-lead, or other surface-mount terminations. For SMT-compatible alternatives, consider the SMAZ75 or P6SMB75A, but note these differ in power rating and impedance.

What is the maximum allowable lead temperature during soldering for 1N5946BG?

The maximum lead temperature for soldering the 1N5946BG is 260°C, applied at a distance of 1/16″ from the case for no longer than 10 seconds. This specification is defined in the Mechanical Characteristics section of the datasheet and ensures bond integrity without damaging the internal silicon-oxide passivated junction.

How does the 1N5946BG's surge rating compare to its steady-state power rating?

The 1N5946BG sustains 98 W for 1 ms nonrepetitive surges (Figure 3), which is over 32× its 3 W steady-state power rating. This high peak-to-continuous ratio enables transient suppression without thermal saturation, provided the average power remains within derated limits - e.g., ≤1 W at 125°C ambient per the derating curve in Figure 1.

Is the 1N5946BG RoHS-compliant and halogen-free?

Yes - the "G" suffix in 1N5946BG explicitly denotes a Pb-free (RoHS-compliant) package per onsemi's ordering nomenclature. While the datasheet confirms Pb-free construction and corrosion-resistant finish, it does not declare halogen-free status; for halogen-free compliance, verify with onsemi's material declaration reports (MDR) or contact their technical support directly.