onsemi 1N5343BG

Overview

1N5343BG from onsemi is a 5 W axial-lead Zener diode with nominal zener voltage of 7.5 V, ±5% tolerance, 175 Ω maximum zener impedance at 1.5 mA test current, and 0.15 mA maximum leakage current at 5.7 V reverse voltage. It operates as a precision voltage reference or shunt regulator in DC power supply feedback paths, overvoltage protection circuits, and voltage-clamping applications.

For engineers reviewing the 1N5343BG datasheet, pinout, applications, or equivalent options, key selection criteria include its 7.5 V regulation point, 175 Ω dynamic impedance, 630 mA maximum DC zener current, Pb-free Surmetic 40 plastic package, and compatibility with standard through-hole PCB assembly processes.

Technical Context

This device uses a silicon-oxide passivated junction to achieve tight voltage tolerance (±5%), low temperature coefficient (≈+3.5 mV/°C for 7.5 V units), and high surge robustness (up to 180 W for 8.3 ms). Its thermal design relies on lead-to-ambient conduction, with junction-to-lead thermal resistance of 25 °C/W at 3/8″ lead length.

The 1N5343BG delivers stable regulation across −65°C to +200°C operating range, supports 1.2 V forward voltage max at 1.0 A, and maintains ≤0.15 mA leakage at VR = 5.7 V - enabling reliable operation in industrial power supplies and automotive subsystems where ambient temperature swings exceed 100°C.

Key Specifications

Pinout & Package

Package: Axial-lead Surmetic 40 plastic case (JEDEC Case 017AA), void-free transfer-molded thermosetting material, cathode indicated by band, leads solderable per 260°C/10 s specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 1N5343B, the 1N5343BG offers identical regulation performance with Pb-free compliance; compared with BZX85C7V5, it delivers 5× higher power handling and superior surge robustness but requires larger PCB footprint and axial-lead assembly.

Availability

1N5343BG is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, test instrumentation, and LED lighting systems requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for 1N5343BG 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, analog, sensors, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 1N53 Series belongs to onsemi's discrete Zener diode product line, engineered for high-reliability voltage regulation in harsh-environment applications where thermal stability, surge resilience, and long-term parameter consistency are critical.

FAQ

What is the exact zener voltage tolerance for 1N5343BG?

The 1N5343BG has a guaranteed ±5% zener voltage tolerance at 25°C, resulting in a specified range of 7.13 V (minimum) to 7.88 V (maximum) at I_ZT = 1.5 mA. This tolerance is defined per JEDEC standards and verified during production testing - not derived from typical or average values.

Can 1N5343BG replace 1N5343B in existing designs?

Yes, the 1N5343BG is a direct Pb-free replacement for 1N5343B with identical electrical specifications, thermal characteristics, and mechanical dimensions. The only difference is the lead finish: 1N5343BG uses matte tin plating compliant with RoHS, while 1N5343B uses SnPb. No layout or schematic changes are required.

What is the maximum DC zener current for 1N5343BG at 25°C?

The maximum DC zener current (I_ZM) for 1N5343BG is 630 mA at 25°C, calculated as P_D/V_Z(min) = 5 W / 7.13 V. This value is confirmed in the onsemi datasheet Table on page 2 and applies under steady-state conditions with proper lead heatsinking.

Does 1N5343BG have a specified temperature coefficient?

Yes, the 1N5343BG exhibits a positive temperature coefficient of approximately +3.5 mV/°C near its 7.5 V operating point, as shown in Figure 2 of the onsemi datasheet. This coefficient is measured at I_ZT and reflects how V_Z changes with junction temperature - critical for high-precision reference designs.

What packaging options are available for 1N5343BG?

The 1N5343BG is supplied in two configurations: 1000 units per box (bulk) and 4000 units per tape-and-reel (1N5343BRLG). Both use the same axial-lead Surmetic 40 plastic package (Case 017AA), with cathode band marking and Pb-free finish. Tape orientation follows EIA-481-D standards.