LD39115J33R

Overview

The LD39115J33R is a fixed-output low-dropout linear voltage regulator manufactured by STMicroelectronics, providing a stable 3.3 V output with a maximum current capacity of 150 mA. It operates within an input voltage range of 1.5 V to 5.5 V and features a typical dropout voltage of 80 mV at 100 mA load. The device exhibits very low quiescent current, typically 20 μA at no load and 35 μA at full load, with shutdown consumption below 1 μA. Noise performance is specified at 33 μV RMS from 1 kHz to 100 kHz. It includes logic-controlled enable functionality, short-circuit protection, and thermal shutdown, housed in a compact 4-bump flip-chip package.

Feature Summary

• Ultra-low dropout voltage operation ensures efficient power delivery with minimal energy loss under varying load conditions.
• Extremely low quiescent current consumption extends battery life in portable and wireless electronic devices.
• Integrated logic-controlled enable pin allows precise system power management and deep sleep mode activation.
• Robust internal protection mechanisms include constant current limiting for short circuits and thermal overload shutdown.

Applications

• Low-power battery-operated consumer electronics
• Wireless communication modules requiring stable supply rails
• Portable medical devices and healthcare equipment
• IoT sensor nodes and embedded control systems

Procurement Notes

Verify the specific suffix 'R' indicates tape-and-reel packaging configuration when sourcing. Confirm component status as obsolete or NRND through official manufacturer channels prior to design finalization. Ensure compatibility with ceramic output capacitors as specified in the datasheet. Validate RoHS compliance and moisture sensitivity levels against project requirements. Cross-reference part numbers with authorized distributors to avoid counterfeit components.

Selection Notes

Select this regulator for applications demanding minimal footprint and high efficiency in low-current scenarios. The fixed 3.3 V output eliminates external resistor networks, simplifying PCB layout. Consider the flip-chip package constraints for thermal dissipation and soldering processes. Evaluate input voltage headroom against the ultra-low dropout characteristic to maintain regulation during battery discharge cycles.

Part Context

This component belongs to the LD39115 family of low-quiescent current LDO regulators designed for space-constrained, battery-powered applications. The series emphasizes low noise and high power supply rejection ratio (PSRR) to protect sensitive analog and RF circuits. The J variant specifically denotes the flip-chip packaging option, offering a significantly smaller footprint compared to traditional leaded packages while maintaining electrical performance standards.

Replacement Considerations

Publicly confirmed substitute part numbers include LP5900TL-3.3/NOPB from Texas Instruments and ADP150ACBZ-3.3-R7 from Analog Devices. Verify pinout compatibility and output voltage tolerance before substitution. Note that package differences may require PCB re-layout or adapter solutions.