1N4899A

Overview

The Microchip Technology 1N4899A/TR is a temperature-compensated Zener diode housed in a DO-7 axial through-hole package. It features a nominal Zener voltage of 12.8 V with a tolerance of ±5% and a maximum power dissipation of 400 mW. The device exhibits a low impedance of 400 Ohms at a test current of 500 uA, with a maximum reverse leakage current of 15 uA. It operates within a temperature range of -65°C to +175°C and includes a voltage temperature coefficient of 0.001 %/C.

Feature Summary

• Temperature compensated design for stable voltage regulation across wide thermal ranges
• Axial leaded construction suitable for through-hole mounting applications
• Low leakage current characteristics ensuring minimal standby power consumption

Applications

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

Procurement Notes

Verify the specific suffix TR indicates reel packaging when sourcing. Confirm RoHS compliance status as documentation may vary by production batch. Ensure the supplier provides official Microchip datasheets to validate the 12.8 V nominal rating and 400 mW power handling capabilities before finalizing procurement orders.

Selection Notes

Select this component when a stable 12.8 V reference is required in high-temperature environments up to 175°C. The DO-7 package suits automated through-hole assembly lines. Consider the 400 Ohm impedance for circuit loading effects and verify that the 400 mW dissipation rating aligns with the expected thermal management constraints of the target application board.

Part Context

This part belongs to the Microchip Zener diode family, specifically designed for temperature compensation. It differs from standard Zener diodes by incorporating structural adjustments to minimize voltage drift over temperature variations. The 1N4899A variant provides a specific 12.8 V output point within the broader series of regulated voltage components offered by the manufacturer.

Replacement Considerations

Cross-reference with other 12.8 V Zener diodes in the DO-7 package. Verify that substitute parts match the 400 mW power rating and ±5% tolerance. Ensure replacement components support the same -65°C to +175°C operating temperature range to maintain system reliability.