LD3985M47R

Overview

The LD3985M47R is a fixed-output low-dropout linear voltage regulator manufactured by STMicroelectronics. It provides a stable 4.7 V output with a maximum load current of 150 mA. The device operates from an input voltage range of 2.5 V to 6 V and utilizes BiCMOS technology. Key electrical characteristics include a typical quiescent current of 85 µA at no load and a dropout voltage of 60 mV at full load. It features internal overcurrent and thermal protection, logic-controlled shutdown, and maintains high power supply rejection ratios across the operating frequency spectrum.

Feature Summary

• Ultra-low dropout voltage performance ensures efficient operation in battery-powered systems
• Logic-controlled electronic shutdown function enables board-level standby modes
• Compatible with low ESR ceramic capacitors for stable regulation
• Integrated overcurrent and thermal limit protection mechanisms

Applications

• Mobile phones and similar wireless communication devices
• Portable information appliances requiring low noise power supplies
• Battery-operated systems optimizing for extended operational life

Procurement Notes

Verify the specific suffix 'M47R' against official STMicroelectronics documentation to confirm the 4.7 V fixed output voltage and TSOT-23-5 package configuration. Ensure compatibility with low ESR ceramic output capacitors as required for stability. Confirm RoHS compliance status and check for automotive-grade alternatives if higher temperature ranges are needed.

Selection Notes

Select this component when a fixed 4.7 V rail is required with minimal voltage drop under 150 mA loads. It is suitable for designs prioritizing low quiescent current to extend battery life. Verify that the input voltage remains within the 2.5 V to 6 V window and that the application environment stays within the -40 °C to +125 °C operating temperature range.

Part Context

This part belongs to the LD3985 series of ultra-low drop and low noise BiCMOS voltage regulators. The series is designed for low-power applications where efficiency and noise performance are critical. The M47 variant specifically fixes the output at 4.7 V, distinguishing it from other fixed-voltage options like 1.8 V or 3.3 V within the same family.

Replacement Considerations

Direct substitutes within the same series include LD3985M18R (1.8 V) and LD3985M33R (3.3 V) if voltage levels differ. For higher current requirements, consider the LDS3985 series which supports up to 300 mA.