NJM431U

Overview

The NJM431U is a three-terminal adjustable precision shunt regulator manufactured by Nisshinbo Micro Devices Inc. It utilizes bipolar technology and operates within a cathode voltage range of VREF to 36V, with a maximum continuous cathode current of 100mA. The device features a reference voltage of approximately 2.5V (typical 2.495V) and offers low dynamic output impedance of 0.2Ω typical. It is housed in an SOT-89 package and supports an operating temperature range from -40°C to +85°C.

Feature Summary

• Adjustable output voltage set between VREF and 36V using two external resistors
• Fast turn-on response capability for precise regulation control
• Low dynamic output impedance ensuring stable performance under varying load conditions

Applications

• Shunt regulators
• Series regulators for small power supplies
• Isolation regulators with photocouplers
• Constant current sources

Procurement Notes

Verify the specific ordering suffix against official documentation, as suffixes may indicate variations in packaging or tape-and-reel specifications without altering the core electrical function. Confirm RoHS compliance status and lead times directly with the manufacturer or authorized distributors prior to procurement. Ensure the selected package variant matches the intended PCB layout requirements.

Selection Notes

Select this component when an adjustable precision shunt regulator is required for applications involving isolation feedback loops or simple voltage referencing. Consider the SOT-89 package for surface-mount designs requiring compact footprints. Evaluate thermal dissipation capabilities relative to ambient temperature and load current to ensure operation remains within the specified safety operating boundary conditions.

Part Context

The NJM431U belongs to the broader NJM431 family of adjustable precision shunt regulators produced by Nisshinbo Micro Devices. This series includes various package options such as DIP8, DMP8, TO-92, and SOT-89. The family is designed for general-purpose voltage reference and regulation tasks, offering compatibility with standard resistor networks for setting output voltages.

Replacement Considerations

Compatible alternatives include other adjustable shunt regulators from different manufacturers that meet similar electrical specifications. Verify pinout compatibility and package dimensions before substitution. Ensure the replacement device supports the required cathode current and voltage ranges for the specific application circuit.