1N4681 (DO35)

Overview

The Microsemi Corporation 1N4681 is a silicon unidirectional Zener voltage regulator diode housed in a hermetically sealed glass DO-35 (DO-204AH) axial-leaded package. It provides a nominal breakdown voltage of 3.3 V with a standard tolerance of ±5%. The device is rated for a maximum power dissipation of 500 mW at +50°C, featuring a derating factor of 4 mW/°C above this temperature. It operates within an extended temperature range from -65°C to +175°C and includes an internal metallurgical bond option.

Feature Summary

• Hermetically sealed glass construction with internal metallurgical bonding
• Voltage regulation across a broad operating current and temperature range
• JEDEC registered axial-leaded package configuration

Applications

• Voltage regulation in electronic circuits
• Overvoltage protection applications
• Reference voltage generation

Procurement Notes

Verify the specific suffix letter on the part number to confirm the exact voltage tolerance, as tighter tolerances are identified by different suffixes. Confirm whether the component requires military screening options such as JAN or JANS grades, which necessitate specific prefixes like MQ or MX. Ensure the procurement matches the required RoHS compliance status, as commercial versions may differ from hermetically sealed variants.

Selection Notes

Select the 1N4681 when a stable 3.3 V reference is needed in high-reliability environments requiring hermetic sealing. Consider the DO-35 package size constraints and the 500 mW power dissipation limit at elevated temperatures. Evaluate the need for internal metallurgical bonding to ensure structural integrity under mechanical stress or radiation exposure.

Part Context

This component belongs to the 1N4678 through 1N4717 series of 0.5 W Zener Voltage Regulators manufactured by Microsemi. The series offers a wide selection of voltages from 1.8 to 43 V in standard packages. The 1N4681 specifically utilizes the DO-35 glass axial-leaded form factor, providing a compact solution for low-power voltage regulation tasks.

Replacement Considerations

Surface mount equivalents are available in the DO-213AA package outline, designated by adding UR or UR-1 suffixes to the base part number.