LM385AXM-1.2

Overview

The LM385AXM-1.2 is a micropower voltage reference diode manufactured by National Semiconductor, now part of Texas Instruments. It functions as a two-terminal bandgap reference providing a nominal output voltage of 1.235 V. The device utilizes bipolar technology and is housed in an 8-pin SOIC surface-mount package (PDSO8). It operates within a commercial temperature range of 0 °C to 70 °C. Key electrical characteristics include a maximum supply current of 8 µA and a maximum voltage temperature coefficient of 150 ppm/°C. The component is designed for low-power applications requiring stable voltage references.

Feature Summary

• Provides precise 1.235 V reference using bandgap technology
• Operates with extremely low quiescent current for power efficiency
• Available in compact surface-mount packaging for space-constrained designs

Applications

• Precision current source circuits
• Battery-powered instrumentation systems
• Data acquisition systems requiring stable reference voltages

Procurement Notes

Verify the manufacturer origin, as National Semiconductor assets were acquired by Texas Instruments. Confirm the specific suffix 'AXM' corresponds to the intended temperature grade and package variant. Ensure compliance requirements are met, as some variants may not be RoHS compliant. Cross-reference datasheets from both National Semiconductor and Texas Instruments archives to confirm pinout and electrical specifications match the design requirements.

Selection Notes

Select this component when a fixed 1.235 V reference is required with minimal power consumption. Compare against adjustable variants if circuit flexibility is needed. Consider the SOIC package constraints for PCB layout. Verify that the 150 ppm/°C temperature coefficient meets the system's accuracy requirements over the 0 to 70 °C operating range. Evaluate alternatives like the LM285 or LM185 if military or extended temperature ranges are necessary.

Part Context

The LM385 series belongs to a family of micropower voltage references that includes the LM185 and LM285. These devices share similar bandgap reference architectures but differ in temperature grades and initial accuracy. The LM385 specifically targets commercial applications. The 'AXM' suffix indicates the specific package type and temperature range. This component serves as a foundational reference element in analog signal conditioning chains.

Replacement Considerations

LM385MX-1.2/NOPB: Direct equivalent from Texas Instruments with lead-free composition. LM385M-1.2: Similar SOIC package variant. LM285Z-1.2: Alternative TO-92 package version for through-hole applications.