LM199AH

LM199AH is a precision temperature-stabilized voltage reference based on a monolithic active Zener structure with an integrated heater. It provides a nominal 6.95 V reference voltage, low dynamic 

impedance, low noise, and very low temperature drift for precision measurement, calibration, instrumentation, and stable analog-reference applications. 

The device is supplied in a hermetic 4-lead TO-46 metal-can package with an internal thermal shield. Its integrated temperature stabilizer maintains the reference element at a controlled 

temperature, reducing the effect of ambient-temperature changes and enabling stable operation over the -55 °C to +125 °C operating range. 

Key Specifications

Specifications are based on the LM199AH reference series documentation. Confirm the full ordering code, electrical grade, heater supply conditions, warm-up behavior, current-setting requirements,

and latest manufacturer datasheet before design use or replacement. 

Key Features

Precision temperature-stabilized monolithic Zener reference. 

Nominal 6.95 V reference-voltage output. 

Reference-voltage range of 6.8 V to 7.1 V. 

Maximum initial reference-voltage tolerance of ±2%. 

Very low maximum temperature coefficient of 0.0001%/°C. 

Wide reference-current operating range from 0.5 mA to 10 mA. 

Typical dynamic impedance of 0.5 Ω. 

Integrated temperature stabilizer and active Zener reference. 

Low-noise precision-reference operation. 

Hermetic TO-46 metal-can package with internal thermal shielding. 

Wide operating-temperature range from -55 °C to +125 °C. 

High reliability and low hysteresis after thermal cycling

Product Advantages

Excellent Temperature Stability

LM199AH uses a heated reference structure to reduce the effect of ambient-temperature variation. Its low temperature coefficient makes it suitable for precision instruments and long-term analog

 measurement systems where reference drift can directly affect measurement accuracy. 

Stable 6.95 V Reference Output

The nominal 6.95 V output can be used directly as a precision reference or scaled to other required voltages through precision resistor networks and buffer circuits. 

Wide Reference-Current Range

The active Zener reference operates from 0.5 mA to 10 mA with limited change in reference voltage and temperature coefficient. This provides flexibility when designing reference-current and bias circuits. 

Low Dynamic Impedance

A typical 0.5 Ω dynamic impedance helps maintain reference stability when the operating current changes within the specified range. 

Hermetic Metal-Can Package

The hermetic TO-46 package and internal thermal shield support stable performance, low thermal hysteresis, and high reliability in precision analog and industrial applications.

Typical Applications

Precision digital multimeters.

High-accuracy voltage-reference modules.

Calibration and metrology equipment.

Precision analog-to-digital converters.

Digital-to-analog converter reference circuits.

Data-acquisition systems.

Industrial instrumentation.

Precision laboratory power supplies.

Test and measurement equipment.

Frequency standards and precision control systems.

Low-drift sensor signal-conditioning circuits.

Alternative Parts

The following parts may be considered as reference alternatives. They are not guaranteed drop-in replacements. Verify output voltage, reference topology, drift, noise, heater requirement, supply conditions, package, pinout, warm-up time, operating temperature, and long-term stability before substitution.

Alternative Selection Guidance

The closest reference alternative is LM199AH/883 when the application requires the same 6.95 V heated-Zener architecture and TO-46 package. LM399AH may be considered for commercial-temperature applications, but its temperature rating is different and must be verified against the end-equipment requirement

FAQ

What is LM199AH?LM199AH is a precision temperature-stabilized active-Zener voltage reference with an integrated heater. It provides a nominal 6.95 V reference output for precision analog and measurement applications. 

What is the output voltage of LM199AH?

LM199AH has a nominal reference voltage of 6.95 V, with a specified reference-voltage range from 6.8 V to 7.1 V. 

Why does LM199AH include a heater?

The integrated heater stabilizes the reference element at a controlled temperature. This reduces the influence of ambient-temperature variation and helps achieve very low temperature drift. 

What is the operating temperature range of LM199AH?

LM199AH is rated for operation from -55 °C to +125 °C. 

What package does LM199AH use?

LM199AH uses a 4-lead hermetic TO-46 metal-can package with an internal thermal shield. 

What is the closest alternative to LM199AH?

LM199AH/883 is the closest family alternative because it uses the same LM199AH heated-Zener reference architecture and 6.95 V output. LM399AH can be considered for commercial-temperature

 applications after confirming temperature, package, electrical, and calibration compatibility. 

Can LM199AH be replaced by a standard voltage reference IC?

Not directly. Standard voltage references often use different output voltages, drift behavior, noise levels, packages, current requirements, and reference architectures. Any substitute should be selected 

only after a full accuracy, thermal, and circuit-compatibility review. 

Request a quote LM199AH at censtry.com. All items are new and original with 365 days warranty! The excellent quality and guaranteed services of LM199AH in stock for sale, check stock quantity and pricing, view product specifications, and order contact us:sales@censtry.com.
The price and lead time for LM199AH depending on the quantity required, please send your request to us, our sales team will provide you price and delivery within 24 hours, we sincerely look forward to cooperating with you.

Direção:

National Semiconductor Corporation, now part of Texas Instruments, has truly outdone themselves with the LM199AH. This amplifier boasts a low input bias current and a high common-mode rejection ratio, making it a go-to choice for applications requiring unparalleled precision and stability. Its metal can package with gold plated leads not only enhances its reliability but also makes it ideal for industrial, medical, and scientific instrumentation where low noise and high accuracy are non-negotiable