LM299AH-20

Overview

The LM299AH-20 is a temperature-stabilized Zener voltage reference IC manufactured by National Semiconductor. It features a fixed output voltage of 6.95V and operates within a supply current range of 20 mA to 28 mA. The device is housed in a TO-46-4 metal can package, designed for high stability applications. It supports an operating temperature range from -25°C to 85°C. Key performance metrics include a maximum noise level of 20 ppm over the 10 Hz to 10 kHz frequency band and a maximum output voltage of 7.1 V.

Feature Summary

• Temperature-stabilized Zener reference design for ultra-stable performance
• Fixed output voltage configuration at 6.95V
• Metal can packaging (TO-46-4) for environmental protection

Applications

• Precision measurement systems requiring stable reference voltages
• High-resolution analog-to-digital converter references
• Calibration equipment needing low-noise DC sources

Procurement Notes

Verify the manufacturer origin, as National Semiconductor assets are now part of Texas Instruments. Confirm the specific suffix '-20' matches the required 6.95V fixed output specification. Ensure the TO-46-4 metal can package is compatible with your assembly process. Check for authenticity markers to avoid counterfeit components in the vintage or surplus market.

Selection Notes

Select this component when ultra-low drift and noise are critical requirements. The LM299AH-20 is suitable for applications demanding higher stability than standard Zener diodes. Consider the through-hole mounting requirement due to the TO-46 package. Compare against the LM399 series if different thermal characteristics or pinouts are needed for the specific circuit topology.

Part Context

This part belongs to the LM199/LM299/LM399 family of precision references. These devices are specially selected from production runs to offer superior stability compared to standard Zener diodes. The 'A' grade indicates tighter tolerance specifications, while the 'H' denotes temperature stabilization. The LM299 variant typically offers a balance of performance and cost for general-purpose precision applications.

Replacement Considerations

The LM399AH-50 is a documented substitute within the same family, offering similar temperature-stabilized Zener characteristics. Verify that the pinout compatibility between the TO-46 packages is maintained during substitution. Ensure the replacement meets the specific 6.95V output requirement if exact voltage matching is necessary.