LM431ACZ/NOPB

Voltage Reference Overview

The LM431ACZ/NOPB is a precision adjustable shunt voltage reference manufactured by Texas Instruments, originating from the National Semiconductor product line. It operates within an input voltage range of 2.495V to 36V and supports a maximum cathode current of 100mA. The device features an initial accuracy of ±2% and maintains operation across a temperature range of -40°C to +85°C. Packaged in a TO-226AA-3 (TO-92) through-hole configuration, it serves as a two-terminal Zener-like regulator with adjustable output capabilities defined by external resistive dividers.

Voltage Reference Feature Summary

• Provides stable reference voltage via two-terminal shunt regulation topology
• Offers adjustable output voltage capability using external resistor networks
• Ensures high precision performance with specified initial accuracy tolerance

Voltage Reference Applications

• Precision voltage references in analog signal conditioning circuits
• Programmable linear power supply feedback loops
• Battery-operated equipment requiring stable reference sources

Voltage Reference Procurement Notes

Verify that the ordering suffix 'NOPB' confirms lead-free compliance and RoHS adherence as per manufacturer specifications. Confirm the package designation matches the required TO-226AA-3 form factor for your PCB layout. Ensure the ACZ variant meets the specific ±2% accuracy requirements for your design rather than tighter or looser tolerance options available in the series.

Voltage Reference Selection Notes

Select this component when a through-hole adjustable shunt regulator is required for industrial or commercial temperature ranges. The 100mA current capacity suits moderate load applications compared to lower-current alternatives. Verify that the 36V maximum input voltage aligns with your system's supply rails. Consider the ±2% initial accuracy sufficient for general-purpose regulation tasks where ultra-high precision is not critical.

Voltage Reference Part Context

This part belongs to the LM431 family of adjustable precision Zener shunt regulators. Originally developed by National Semiconductor before its acquisition by Texas Instruments, the LM431 series replaced traditional fixed-voltage Zener diodes by offering adjustable reference outputs. The LM431ACZ/NOPB represents the standard accuracy version in the through-hole TO-92 package, widely used in legacy and new designs requiring reliable shunt regulation.

Voltage Reference Replacement Considerations

Direct pin-compatible substitutes include the LM431AIQ/NOPB for tighter accuracy or LM431AIMX/NOPB for surface mount applications. Cross-reference with LM431 variants from other manufacturers only if electrical parameters such as cathode current and reference voltage range are strictly matched.