1N4904

Overview

The Microchip Technology 1N4904 is a temperature compensated Zener diode designed for precision voltage regulation applications. It features a nominal Zener voltage of 12.8 V with a tolerance of ±5%. The device supports a maximum power dissipation of 400 mW and operates within an extended temperature range from -55°C to +175°C. Housed in the DO-35 axial through-hole package, it exhibits a maximum Zener impedance of 100 Ohms and a low reverse leakage current of 15 µA. This component is suitable for environments requiring stable reference voltages under varying thermal conditions.

Feature Summary

• Temperature compensation capability ensures stable voltage regulation across wide thermal variations
• Precision voltage reference with tight manufacturing tolerance for accurate circuit performance
• Robust axial leaded construction suitable for high-reliability through-hole mounting

Applications

• Precision voltage reference circuits
• Temperature compensated regulator designs
• High-reliability industrial instrumentation

Procurement Notes

Verify the specific suffix requirements when ordering, as packaging options such as bulk or tape-and-reel may vary by manufacturer lot. Confirm RoHS compliance status if required for your assembly process, as standard versions may differ from environmental compliant variants. Cross-reference the exact part number with official Microchip documentation to ensure compatibility with your design specifications before finalizing procurement.

Selection Notes

Select this component when a stable 12.8 V reference is needed with minimal drift over temperature. Ensure the 400 mW power rating aligns with your circuit's thermal dissipation capabilities. Verify that the axial DO-35 package fits your PCB layout constraints. Consider the ±5% tolerance against your system's accuracy requirements to determine if tighter specifications are necessary.

Part Context

This device belongs to the family of temperature compensated Zener diodes, distinct from standard Zener diodes which lack thermal correction. Unlike general-purpose rectifiers, it is optimized for maintaining a constant voltage drop despite ambient temperature changes. The 1N4904 variant specifically targets applications where voltage stability is critical, offering superior performance compared to uncompensated counterparts in fluctuating thermal environments.

Replacement Considerations

Direct substitutes include other temperature compensated Zener diodes with matching 12.8 V nominal voltage and similar power ratings. Verify pinout compatibility and package dimensions before substitution. Ensure the replacement device meets the same operating temperature range and impedance specifications to maintain circuit integrity.