1N4903A

Overview

The Microchip Technology 1N4903A is a temperature-compensated Zener diode designed for precision voltage regulation applications. It features a nominal Zener voltage of 12.8 V with a tight tolerance of ±5%. The device operates in the DO-7-2 axial through-hole package, supporting a maximum power dissipation of 400 mW. Key electrical characteristics include a test current of 2 mA, a maximum reverse leakage current of 15 µA, and a Zener impedance of 100 Ohms. It exhibits a voltage temperature coefficient of 0.01 %/°C, ensuring stable performance across an operating temperature range from -65°C to +175°C.

Feature Summary

• Temperature compensated design ensures minimal voltage drift over wide thermal ranges
• Precision voltage regulation with tight manufacturing tolerance for critical circuits
• Robust high-temperature operation capability suitable for demanding environments

Applications

• Precision voltage reference sources in measurement instrumentation
• Temperature-stable biasing networks in analog signal processing
• Over-voltage protection circuits requiring consistent threshold levels

Procurement Notes

Verify the specific suffix /TR indicates reel packaging when ordering. Confirm RoHS compliance status as indicated by manufacturer documentation. Ensure the DO-7-2 axial lead form factor matches the target PCB layout requirements. Validate that the 400 mW power rating aligns with the expected thermal dissipation in the final assembly environment.

Selection Notes

Select this component when circuit stability requires low temperature coefficients near the 12V breakdown region. The 12.8V nominal value provides a standard reference point for regulator designs. Consider the 100 Ohm impedance for noise-sensitive applications where lower dynamic resistance is beneficial compared to higher impedance alternatives.

Part Context

This part belongs to the 1N49xx series of temperature-compensated Zener diodes manufactured by Microchip Technology. These devices utilize specialized doping profiles to achieve near-zero temperature coefficients at specific voltage points, distinguishing them from standard Zener diodes which exhibit significant thermal drift.

Replacement Considerations

Cross-reference with other manufacturers offering 12.8V temperature-compensated Zeners in DO-7 packages. Verify equivalent specifications for voltage tolerance, power dissipation, and temperature coefficient before substitution.