1N2991B

Overview

The Microchip Technology 1N2991B is a silicon unidirectional voltage regulator diode with a nominal Zener voltage of 36 V and a maximum power dissipation of 10 W. It features a ±5% voltage tolerance and operates within a temperature range of -65 °C to +175 °C. The device utilizes a DO-4 (DO-213AA) hermetically sealed metal case designed for stud mounting. Key electrical parameters include a maximum reverse leakage current of 10 µA, a Zener impedance of 10 Ω, and a test current of 230 mA.

Feature Summary

• Hermetically sealed metal construction in a DO-4 package for high reliability industrial applications
• Unidirectional voltage regulation capability with stable Zener characteristics
• Extended thermal performance supporting operation up to 175 °C junction temperature

Applications

• High-reliability industrial voltage regulation circuits
• Chassis or stud-mounted power supply protection
• Industrial equipment requiring hermetic sealing

Procurement Notes

Verify the manufacturer origin carefully, as New Jersey Semiconductor and Microchip Technology both produce this part number. Confirm the specific suffix if reverse polarity variants are required. Ensure the DO-4 stud-mount configuration matches your mechanical design requirements before procurement.

Selection Notes

Select this component when a 36 V reference is needed in a ruggedized, hermetically sealed environment. The DO-4 package requires stud mounting, which influences PCB layout and thermal management strategies compared to surface-mount alternatives.

Part Context

This component belongs to the 1N2970B series of 10 W Zener diodes manufactured by New Jersey Semiconductor and Microchip Technology. The series covers a wide voltage range from 6.8 V to 200 V, all sharing the same hermetically sealed metal case and high-reliability specifications for industrial use.

Replacement Considerations

Equivalent parts include the 1N2991B produced by New Jersey Semiconductor and Digitron. Verify that replacement units maintain the DO-4 hermetic seal and stud-mount form factor to ensure compatibility with existing mechanical assemblies.