LM231N/NOPB

Overview

The LM231N/NOPB is a precision voltage-to-frequency converter manufactured by Texas Instruments. It operates within an input voltage range of 4V to 40V and supports output frequencies up to 100 kHz. The device features an initial accuracy of ±0.01% and a full-scale temperature coefficient of ±50 ppm/°C. It is housed in an 8-pin PDIP package with a width of 0.300 inches (7.62 mm). The component functions as a linear voltage-to-frequency converter, suitable for applications requiring high precision signal conversion.

Feature Summary

• Provides precise conversion of analog voltage signals into proportional digital frequency outputs
• Maintains high linearity performance with minimal deviation across the operating range
• Offers stable frequency generation with low sensitivity to temperature variations

Applications

• Precision measurement systems requiring voltage-to-digital conversion
• Industrial process control loops utilizing frequency-based signaling
• Data acquisition systems interfacing analog sensors with digital processors

Procurement Notes

Verify the specific suffix designation against the manufacturer's current documentation to ensure compliance with RoHS standards and lead-free requirements. Confirm that the PDIP-8 package dimensions match the target PCB footprint. Cross-reference the datasheet revision date to validate electrical characteristics against the production batch. Ensure the supply chain source provides authentic components to avoid counterfeit risks associated with legacy semiconductor parts.

Selection Notes

Select this component when designing circuits that require a direct interface between analog voltage sources and frequency-counting digital logic. It is appropriate for applications demanding high linearity and low temperature drift without the complexity of external oscillator calibration. Consider the through-hole mounting requirement and the maximum operating frequency limits when evaluating system bandwidth constraints and physical layout restrictions.

Part Context

This part belongs to the LMx31 family of precision voltage-to-frequency converters, originally developed by National Semiconductor and continued by Texas Instruments. The LM231 variant typically offers improved performance specifications compared to the standard LM331, including tighter accuracy and lower noise. The NOPB suffix indicates a lead-free and environmentally friendly version compliant with modern manufacturing standards.

Replacement Considerations

The LM331N/NOPB serves as a functional equivalent within the same family, though electrical tolerances may differ slightly. Other compatible alternatives include the LM131A/LM331A series for industrial grade variants. Verify pin compatibility and thermal characteristics before substituting with generic V/F converter ICs from other manufacturers.