onsemi 1N5938BG

Overview

1N5938BG from onsemi is a 3 W, 36 V ±5% Zener diode in DO-41 axial package, designed for precision voltage regulation and overvoltage protection in DC power rails. It delivers 27.4 mA maximum DC Zener current (IZM), exhibits 10.4 Ω Zener impedance at 38 mA test current (ZZT), and maintains stable regulation across −65°C to +200°C junction temperature range - commonly used in industrial power supply feedback loops and analog reference circuits.

For engineers reviewing the 1N5938BG datasheet, pinout, applications, or equivalent options, key selection criteria include its 36 V nominal Zener voltage with tight ±5% tolerance, 98 W surge rating at 1 ms, Class 3 ESD robustness (>16 kV HBM), and compatibility with standard through-hole PCB assembly processes requiring no reflow profile adaptation.

Technical Context

The 1N5938BG operates as a silicon-oxide passivated Zener regulator, leveraging a thermally stable junction to maintain precise reverse breakdown voltage under varying load and temperature conditions. Its 3 W steady-state power dissipation at TL = 75°C (with 24 mW/°C derating) supports continuous operation in compact, non-heatsinked designs.

It features low dynamic impedance (10.4 Ω @ IZT = 38 mA) and minimal leakage (0.25 μA @ VR = 27.4 V), enabling high-accuracy voltage clamping in feedback networks and reference shunt applications. The DO-41 package ensures mechanical reliability and solderability per IPC-J-STD-001 standards, with cathode polarity clearly marked by a band.

Key Specifications

Pinout & Package

Package: DO-41 axial-leaded plastic case (Case 59-10), 5.2 mm max body length × 2.7 mm max diameter, cathode indicated by single black band. Lead diameter uncontrolled within 0.86 mm max, lead length standard 3/8″ for thermal derating compliance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5938BRLG, the 1N5938BG offers identical regulation performance in box-packaged form for manual or semi-automated assembly; versus BZX85C36, it provides 2.3× higher power handling and 3.5× lower dynamic impedance - critical for maintaining stability in closed-loop power supplies.

Availability

1N5938BG is available at Aetrix Electronics and suitable for industrial power supplies, automotive battery management systems, and programmable logic controller (PLC) input modules requiring stable component supply with full traceability and long-lifecycle support.

Supply support for 1N5938BG 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 management, signal processing, and sensing technologies for automotive, industrial, and cloud infrastructure markets.

The 1N59xxB Series is part of onsemi's legacy Zener regulator portfolio, engineered for high-reliability voltage reference and clamping in harsh-environment applications where long-term parametric stability and surge resilience are mandatory.

FAQ

What is the Zener voltage tolerance of the 1N5938BG?

The 1N5938BG has a nominal Zener voltage of 36 V with a guaranteed tolerance of ±5%, meaning its actual breakdown voltage falls between 34.2 V and 37.8 V when measured at 30°C lead temperature and 38 mA test current (IZT). This tolerance is confirmed in the Electrical Characteristics table of the official onsemi datasheet Rev. 9 (July 2024), and applies across the full operating temperature range.

Can the 1N5938BG be used in surface-mount designs?

No - the 1N5938BG is strictly a through-hole DO-41 axial-leaded device and is not compatible with SMT reflow processes. Its lead geometry and thermal mass require wave soldering or hand-soldering. For SMT equivalents, consider the 1N5938BRLG (same specs, tape-and-reel) or evaluate SOD-123 packaged alternatives like MMBZ5245B, though those differ in power rating and impedance.

What is the maximum surge power the 1N5938BG can handle?

The 1N5938BG is rated for 98 W non-repetitive surge power at 1 ms pulse width, as specified in Figure 3 of the onsemi datasheet. This capability allows it to absorb transient overvoltages such as load dump or inductive switching spikes without damage, provided the duty cycle remains below 0.1% and ambient temperature stays within limits.

How does the 1N5938BG's Zener impedance affect circuit performance?

The 1N5938BG's Zener impedance is 10.4 Ω at 38 mA (IZT), directly determining how much its output voltage varies under changing load current. For example, a 10 mA change in Zener current causes ~104 mV shift in regulated voltage - making it suitable for medium-precision references but requiring additional filtering if sub-50 mV stability is needed in sensitive analog circuits.

Is the 1N5938BG RoHS compliant and halogen-free?

Yes - the "G" suffix in 1N5938BG explicitly denotes a Pb-free, RoHS-compliant package per EU Directive 2011/65/EU. onsemi confirms full compliance with halogen-free requirements (IEC 61249-2-21) for this part, with chlorine and bromine content each below 900 ppm, as documented in their material declarations and packaging specification BRD8011/D.