LDLN025J33R

Overview

The LDLN025J33R is a 250 mA ultra-low noise low-dropout linear regulator from STMicroelectronics, designed for noise-sensitive loads. It operates within an input voltage range of 1.5 V to 5.5 V and provides a fixed output voltage of 3.3 V. The device features an ultra-low output noise of 6.5 µVRMS and high power supply rejection ratio (PSRR) of 80 dB at 100 Hz. Quiescent current is 12 µA at no-load, extending battery life in standby modes. It includes logic-controlled shutdown with consumption below 1 µA, internal soft-start, and protection against overcurrent and thermal overload.

Feature Summary

• Ultra-low noise performance suitable for precision analog circuits
• High PSRR ensures clean output under varying line conditions
• Logic-controlled electronic shutdown for deep sleep applications
• Compact footprint with multiple small package options

Applications

• Noise-sensitive loads such as precision ADCs
• Voltage Controlled Oscillators (VCO) in mobile phones and tablets
• Wireless LAN devices
• Medical sensors and fitness monitors

Procurement Notes

Verify the specific suffix 'J33R' corresponds to the 3.3 V fixed output variant and the designated package type (e.g., DFN4 or SOT23-5L) as listed in the official datasheet. Confirm that the ordering code matches the required temperature range and packaging specifications for your production environment.

Selection Notes

Select this component when powering ultra-sensitive RF or analog sections requiring minimal ripple. The fixed 3.3 V output eliminates external resistor networks. Ensure the application benefits from the low quiescent current during dropout conditions to maximize battery-operated device runtime.

Part Context

This part belongs to the LDLN025 series of 250 mA LDO regulators optimized for space-constrained portable electronics. It complements other ST low-noise regulators by offering a balance of high PSRR and ultra-low static current, targeting markets like smartphones, wearables, and IoT devices where power efficiency and signal integrity are critical.

Replacement Considerations

Check for direct pin-compatible alternatives within the same LDLN family with different output voltages if system requirements change. Verify that any substitute maintains the required 250 mA current capability and similar noise specifications for sensitive load compatibility.

FAQ

What is the typical dropout voltage at maximum load?

The typical dropout voltage is 120 mV at a 250 mA load.

How does the device handle shutdown mode?

The enable logic control function places the device into shutdown mode, reducing total current consumption to less than 1 µA.