1N4121 (DO35)

Single Zener Diodes Overview

The Microsemi Corporation 1N4121 (DO35) is a Zener diode with a nominal voltage of 33.0 V and a maximum power dissipation of 0.5 W. It operates within a junction temperature range of -65 to +175 °C. The device features a standard tolerance of ±5% on the nominal Zener voltage, measured at a test current of 250 µA. Maximum reverse current is specified at 40 µA, while the maximum dynamic impedance is 0.01 Ω. The component utilizes an internal metallurgical bond and hermetically sealed glass DO-35 package.

Single Zener Diodes Feature Summary

• Internal metallurgical bond construction for high reliability
• Hermetically sealed axial-lead glass DO-35 package
• Inherently radiation hard design
• Non-sensitive to electrostatic discharge

Single Zener Diodes Applications

• Voltage regulation over broad operating current and temperature ranges
• High reliability applications requiring MIL-PRF-19500/435 qualification
• Low noise signal processing circuits

Single Zener Diodes Procurement Notes

Verify the specific suffixes required for your application, such as 'TR' for tape and reel packaging or 'e3' for RoHS compliance. Confirm that the commercial grade availability aligns with your environmental requirements. Ensure the ordering nomenclature matches the desired reliability level, including JAN, JANTX, JANTXV, or JANS, as these affect the final part number structure.

Single Zener Diodes Selection Notes

Select this component when a stable 33.0 V reference is needed in a ruggedized environment. The low dynamic impedance and minimal capacitance make it suitable for precision applications. Consider the available tighter tolerances if higher accuracy is required, though the standard version provides a robust baseline for general voltage regulation tasks across wide thermal conditions.

Single Zener Diodes Part Context

This device belongs to the 1N4099 through 1N4135 series of 500 mW Zener voltage regulators manufactured by Microsemi. These components are designed for demanding environments and offer extensive voltage selection from 1.8 to 100 volts. The series supports various reliability qualifications and packaging options, including surface mount variants, to accommodate diverse circuit board layouts and performance specifications.

Single Zener Diodes Replacement Considerations

Direct replacements include other 1N4121 variants with different suffixes for tolerance or packaging, such as 1N4121C-1 or 1N4121D-1. Cross-referencing with equivalent JEDEC registered parts from other manufacturers requires verifying matching electrical characteristics, specifically the 33.0 V nominal voltage and 0.5 W power rating.

Single Zener Diodes FAQ

What is the maximum noise density for the 1N4121?

The maximum noise density is 40 μV / √Hz.

How does the 1N4121 handle electrostatic discharge?

The device is non-sensitive to ESD per MIL-STD-750 method 1020.