1N990B

Single Zener Diodes Overview

The Microchip Technology 1N990B is a silicon Zener voltage regulator diode with a nominal breakdown voltage of 160 V. It operates within the JEDEC registered 1N957B through 1N992B series, featuring a standard 5% tolerance indicated by the 'B' suffix. The device is housed in a hermetically sealed glass DO-35 (DO-204AH) axial-lead package and supports a steady-state power dissipation of 0.5 watts at lead temperatures below 50°C. Electrical characteristics include a maximum dynamic impedance of 1700 Ohms at a test current of 0.8 mA, a maximum reverse leakage current of 121.6 µA, and a temperature coefficient of +0.11 %/°C.

Single Zener Diodes Feature Summary

• Provides stable voltage regulation across a broad operating current and temperature range
• Features flexible axial-lead mounting terminals for through-hole integration
• Constructed with a hermetically sealed glass body to ensure environmental durability
• Inherently radiation hard as described in Microsemi MicroNote 050

Single Zener Diodes Applications

• Voltage reference circuits requiring high-voltage stability
• Overvoltage protection stages in electronic systems
• Power supply regulation modules
• Temperature compensated biasing networks

Single Zener Diodes Procurement Notes

Verify the specific ordering suffix against the manufacturer's datasheet to confirm exact electrical tolerances and compliance options. The base part number indicates a 5% voltage tolerance; alternative suffixes exist for tighter tolerances or RoHS compliance. Confirm package availability and lead material specifications prior to procurement to ensure compatibility with assembly processes.

Single Zener Diodes Selection Notes

Select this component when a precise 160 V reference is required in a compact axial-lead form factor. Ensure the circuit design accommodates the specified maximum DC Zener current of 2.2 mA to prevent exceeding the 0.5 W power dissipation limit. Consider the thermal resistance characteristics if the device will be mounted on FR4 PCBs without adequate copper pad sizing.

Single Zener Diodes Part Context

This device belongs to the widely utilized 1N957B through 1N992B series of 0.5-watt Zener diodes manufactured by Microsemi (now Microchip Technology). The series covers a voltage range from 6.8 V to 200 V, offering extensive selection for various regulation needs. The 1N990B specifically addresses the higher voltage end of this spectrum, providing a reliable solution for applications demanding robust voltage clamping capabilities.

Single Zener Diodes Replacement Considerations

Equivalent devices within the same series include the 1N991B and 1N992B, which offer similar packaging but different nominal voltages. Cross-referencing with other manufacturers requires verifying that the replacement meets the 1700 Ohm maximum dynamic impedance and 0.5 W power rating specifications.