LX432CSC

Overview

The LX432CSC is a low-voltage adjustable precision shunt regulator manufactured by Microsemi (now Microchip Technology). It features an internal reference voltage of 1.24V and allows output voltage adjustment between 1.24V and 20V using two external resistors. The device operates with a cathode current range from 80µA to 20mA and offers a typical dynamic impedance of 250mΩ. It is housed in a 3-lead SOT-23 package, supports an operating temperature range of 0°C to 70°C, and provides initial voltage reference accuracy of 1%.

Feature Summary

• Adjustable output voltage capability ranging from the internal reference level up to 20V via external resistor networks
• Low power operation suitable for portable applications with minimum operating current as low as 80µA
• Low output impedance design ensuring improved load regulation performance
• Direct drop-in replacement compatibility with TLV431 and SC431L devices

Applications

• Low voltage adjustable power supplies
• Isolated feedback loops in power converters
• Portable equipment requiring micropower regulation
• Instrumentation systems

Procurement Notes

Verify component authenticity through authorized Microchip or Microsemi distributors. Confirm the specific suffix 'C' indicates the commercial temperature grade (0°C to 70°C) and 'SC' denotes the SOT-23 package. Ensure compliance with RoHS standards if required by your manufacturing process. Cross-reference datasheet revisions to confirm parameter stability before finalizing procurement specifications.

Selection Notes

Select this component when a low-cost, adjustable shunt regulator is needed for low-voltage circuits. The LX432CSC is appropriate for designs requiring a 1.24V reference baseline. Consider the thermal resistance characteristics of the SOT-23 package for heat dissipation requirements. Verify that the application's minimum cathode current exceeds the 80µA regulation threshold to ensure stable operation across the intended load conditions.

Part Context

This part belongs to the LX432 series of precision shunt regulators originally produced by Microsemi Integrated Products Division. Following corporate acquisitions, these products are managed under Microchip Technology. The LX432 series is designed to provide a cost-effective alternative to standard bandgap references, offering high accuracy and low standby current for embedded control and power management applications.

Replacement Considerations

The datasheet identifies the TLV431 and SC431L as direct functional alternatives. Verify pinout compatibility and electrical parameter alignment, specifically reference voltage and operating current ranges, before substituting. Ensure the replacement device meets the same package and environmental specifications required by the existing design.

FAQ

What is the minimum cathode current required for the LX432CSC to maintain regulation?

The device requires a minimum cathode current of 80µA at 25°C to ensure proper regulation.

How is the output voltage of the LX432CSC adjusted?

The output voltage is set to any value between 1.24V and 20V using two external resistors connected to the reference terminal.

Can the LX432CSC be used in isolated power supply feedback loops?

Yes, low voltage operation enables its use in the feedback loop of isolated low voltage power supplies, provided the minimum output voltage accounts for the opto-coupler LED forward voltage drop.