LDLN025PU50R

Overview

The LDLN025PU50R is a fixed-output low-dropout linear regulator from STMicroelectronics, providing a stable 5 V output with a maximum current capacity of 250 mA. It operates within an input voltage range of 1.5 V to 5.5 V and features ultra-low noise performance of 6.5 µVRMS. The device maintains high power supply rejection ratios of 80 dB at 100 Hz and 60 dB at 100 kHz. Quiescent current is minimized to 12 µA at no-load, extending battery life in portable devices. It includes internal soft-start, overcurrent protection, thermal shutdown, and logic-controlled enable functionality.

Feature Summary

• Ultra-low noise operation suitable for sensitive RF and analog loads
• High power supply rejection ratio ensures clean output under varying conditions
• Logic-controlled electronic shutdown reduces total current consumption below 1 µA
• Integrated safety features including short-circuit, thermal, and overcurrent protection

Applications

• Noise-sensitive loads such as precision ADCs and VCOs
• Mobile phones and tablets requiring compact power solutions
• Wireless LAN devices and IoT sensors
• Battery-powered equipment needing extended standby time

Procurement Notes

Verify the specific package variant, as the LDLN025 series utilizes multiple form factors including Flip-Chip4, DFN4-1x1, and SOT23-5L. Confirm that the PU suffix corresponds to the required surface-mount configuration for your PCB layout. Ensure compatibility with ceramic capacitors for stability. Check current availability status as distribution channels may report varying stock levels or end-of-life notices.

Selection Notes

Select this component when ultra-low noise and high PSRR are critical for signal integrity in space-constrained designs. It is appropriate for applications requiring precise voltage regulation with minimal quiescent current draw. Consider the available output voltage steps ranging from 1 V to 5 V if alternative setpoints are needed. Evaluate the thermal performance within the -40 °C to +125 °C operating range for your specific environment.

Part Context

This part belongs to the LDLN025 series of 250 mA ultra-low noise LDO regulators designed for mobile and portable electronics. The series offers various fixed output voltages and small package options to support miniaturization trends in smartphones, smartwatches, and medical sensors. It complements other STMicroelectronics PMIC solutions by addressing specific noise-sensitive power requirements.

Replacement Considerations

Direct substitutes within the same family include LDLN025J50R, which shares identical electrical specifications but utilizes a Flip-Chip4 package instead of the DFN4-1x1 format. Verify pinout compatibility and thermal pad requirements before substitution.