LM431BIZ

Voltage Reference Overview

The LM431BIZ is a three-terminal adjustable shunt regulator from the LM431 series, manufactured by onsemi. It features an operating temperature range of -40°C to +85°C and offers a reference voltage tolerance of ±1%. The device supports programmable output voltages up to 36 V with two external resistors. Key electrical characteristics include a typical dynamic output impedance of 0.2 Ω, a sink current capability ranging from 1.0 mA to 100 mA, and a full-range temperature coefficient of 50 ppm/°C. It utilizes a TO-92 package.

Voltage Reference Feature Summary

• Programmable output voltage adjustable between approximately 2.5 V and 36 V using external resistors
• Low dynamic output impedance providing sharp turn-on characteristics suitable for Zener diode replacement
• Temperature compensated operation across the full rated industrial temperature range

Voltage Reference Applications

• Shunt regulator circuits
• Output control for three-terminal fixed regulators
• High-current shunt regulation
• Current limit or constant-current sink applications

Voltage Reference Procurement Notes

Verify component status before procurement as the LM431A/D datasheet indicates discontinuation for specific variants within this family. Confirm that the LM431BIZ variant matches the required ±1% tolerance and -40°C to +85°C operating range specifications. Ensure compatibility with TO-92 through-hole mounting requirements and validate supply chain availability directly with authorized distributors.

Voltage Reference Selection Notes

Select the LM431BIZ when precise voltage referencing is required in industrial environments due to its extended low-temperature rating compared to standard commercial grades. The ±1% initial accuracy makes it suitable for applications demanding tighter tolerances than the standard ±2% options. Consider the 100 mA cathode current capability for load driving needs and verify thermal dissipation limits within the TO-92 package constraints.

Voltage Reference Part Context

The LM431BIZ belongs to the LM431A/B/C family of programmable shunt regulators produced by onsemi. This series serves as a versatile alternative to traditional Zener diodes, offering superior stability and adjustability. The 'I' suffix denotes the extended industrial temperature range, distinguishing it from the 'C' variant which operates from -25°C to +85°C.

Voltage Reference Replacement Considerations

LM431CCZ (Discontinued)

Voltage Reference FAQ

What is the minimum cathode current required for regulation?

The minimum cathode current for regulation (IKA(MIN)) is typically 1.0 mA.

How does the LM431BIZ compare to a Zener diode?

It provides an active output circuit with a sharp turn-on characteristic and lower dynamic impedance, making it an excellent replacement for Zener diodes in many applications.