1N4902A

Overview

The Microchip Technology 1N4902A is a temperature-compensated Zener diode with a nominal voltage of 12.8 V and a tolerance of ±5%. It features a maximum power dissipation of 400 mW and a Zener impedance of 200 Ohms at a test current of 1 mA. The device supports through-hole mounting in a DO-7 (DO-204AA) axial package. It operates within a junction temperature range of -65°C to +175°C, with a maximum reverse leakage current of 15 µA.

Feature Summary

• Temperature compensation for stable voltage regulation across wide thermal ranges
• High reliability construction suitable for demanding environments
• Axial leaded package design for standard through-hole integration

Applications

• Precision voltage reference circuits requiring thermal stability
• Overvoltage protection in sensitive electronic systems
• Voltage regulation in industrial control equipment

Procurement Notes

Verify the specific suffix (e.g., /TR for reel packaging) against project requirements, as the base part number may denote bulk packaging. Confirm RoHS compliance status directly with the manufacturer or authorized distributors, as historical data indicates variations. Ensure the ordering quantity matches the supplier's minimum order multiples, which often require purchasing in full reels or specific bulk increments.

Selection Notes

Select this component when a stable 12.8 V reference is needed with low temperature drift. The 400 mW power rating suits low-current applications. Verify that the 200 Ohm impedance meets circuit noise and regulation specifications. Ensure the through-hole DO-7 package fits the PCB layout constraints and that the high operating temperature range aligns with the environmental conditions of the final assembly.

Part Context

This component belongs to Microchip’s legacy Zener diode portfolio, maintaining compatibility with traditional MIL-spec designs. It serves as a direct replacement for older industry-standard parts in existing schematics. The product line emphasizes long-term availability and consistency for critical infrastructure and defense electronics where component obsolescence must be minimized.

Replacement Considerations

Direct substitutes include the CDLL4900A/TR for surface-mount applications, though power ratings and packages differ. Verify pinout and electrical parameters before swapping with generic equivalents to ensure thermal and voltage tolerances match the original design intent.