LD39115J18R

Overview

The LD39115J18R is a low-dropout linear voltage regulator from STMicroelectronics providing a fixed 1.8 V output with a maximum current 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. It includes logic-controlled enable functionality, short-circuit constant current limiting, and thermal protection. The regulator is stabilized by a ceramic capacitor and housed in a compact 4-bump flip-chip package measuring 0.8 x 0.8 mm.

Feature Summary

• Ultra-low dropout voltage capability for efficient power management in battery-powered systems
• Very low noise performance suitable for sensitive analog and RF circuits
• Logic-controlled electronic shutdown for extended battery life in portable devices
• Integrated short-circuit and thermal protection for enhanced system reliability

Applications

• Low-power battery-operated consumer electronics
• Portable medical devices requiring stable low-noise power supplies
• Wireless communication modules and IoT sensors
• Handheld computing devices and mobile peripherals

Procurement Notes

Verify the specific suffix 'R' indicates reel packaging when ordering. Confirm the fixed 1.8 V output variant matches the design requirement, as other voltages exist in the LD39115J family. Check for NRND status or lifecycle changes directly with STMicroelectronics before finalizing procurement plans. Ensure compatibility with the required 1 μF ceramic output capacitor for stability.

Selection Notes

Select this component when a fixed 1.8 V rail is needed with minimal footprint and ultra-low quiescent current. The LD39115J18R is appropriate for designs prioritizing noise immunity and battery efficiency over adjustable voltage flexibility. Consider the 4-bump flip-chip package constraints during PCB layout. Verify that the input voltage remains above the minimum threshold while accounting for dropout characteristics under maximum load conditions.

Part Context

The LD39115J18R belongs to the LD39115 series of low-quiescent-current, low-noise LDO regulators designed for space-constrained applications. This series is characterized by its ability to operate with small ceramic capacitors and its robust protection features. The J suffix denotes the flip-chip package option, distinguishing it from other package variants within the same electrical specification family.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult STMicroelectronics for direct replacements or evaluate alternative LDOs with similar 150 mA output, 1.8 V fixed output, and flip-chip packaging requirements.