LDK120PU18R

Overview

The LDK120PU18R is a fixed-output linear low-dropout regulator (LDO) from STMicroelectronics, providing a stable 1.8V output with a maximum current of 200mA. It operates within an input voltage range of 1.9V to 5.5V and features a typical dropout voltage of 100mV at 100mA load. The device maintains stability using only a 1µF ceramic capacitor on the output. Key electrical characteristics include a maximum quiescent current of 100µA and a power supply rejection ratio (PSRR) of 55dB across the 120Hz to 10kHz frequency band. It incorporates enable logic control for shutdown modes with consumption below 1µA, alongside internal overcurrent and thermal protection mechanisms.

Feature Summary

• Ultra-low dropout performance ensures efficient regulation in battery-powered applications
• Logic-controlled electronic shutdown enables deep sleep states with minimal current drain
• Compatible with small ceramic output capacitors for compact board designs
• Integrated short-circuit constant current limiting and thermal protection safeguards operation

Applications

• Low-power battery-operated consumer electronics
• Always-on automotive body and interior functions
• Industrial systems requiring stable voltage rails
• IoT devices with strict power consumption constraints

Procurement Notes

Verify the complete part number including suffixes such as 'R' for reel packaging against official STMicroelectronics documentation. Confirm that the specific output voltage variant matches the design requirement, as the LDK120 series offers multiple fixed voltage options. Ensure compatibility with the required package type, typically 6-DFN or SOT variants, before finalizing procurement specifications.

Selection Notes

Select this component when a fixed 1.8V rail is required with moderate current demands up to 200mA. It is suitable for designs prioritizing low noise and high PSRR in space-constrained environments. Consider the input voltage range limits and ensure the dropout voltage remains within acceptable bounds for the specific load conditions. Verify thermal dissipation capabilities based on the chosen package and ambient operating temperature.

Part Context

This regulator belongs to the LDK120 family of ultra-low dropout linear regulators designed for low quiescent current and very low noise applications. The family provides various fixed output voltages and adjustable versions to support diverse system requirements. Manufactured by STMicroelectronics, these devices are optimized for portable and battery-driven equipment where efficiency and size are critical factors.

Replacement Considerations

Consult official STMicroelectronics substitution guides for verified alternatives. Cross-reference pinouts and electrical parameters carefully when considering generic LDO replacements to ensure functional compatibility.