LD39020ADTPU18R

Overview

The LD39020ADTPU18R is a fixed-output low-dropout linear regulator manufactured by STMicroelectronics. It provides a stable 1.8 V output with a maximum current capacity of 200 mA. The device operates within an input voltage range of 1.5 V to 5.5 V and features a typical dropout voltage of 200 mV at full load. It incorporates a very low quiescent current of 20 µA and achieves high power supply rejection ratios of 80 dB at 1 kHz. The component utilizes a compact 4-DFN (1x1 mm) surface-mount package and supports operation across a temperature range of -40 °C to +125 °C.

Feature Summary

• Ultra-low dropout voltage capability for efficient power management in battery-operated systems
• Logic-controlled electronic shutdown function enabling deep sleep modes with minimal current consumption
• Internal soft-start circuitry to limit inrush current during startup phases
• Integrated thermal and constant current protection mechanisms for enhanced reliability

Applications

• Low-power battery-operated portable electronics
• Smartphones and tablet devices requiring precise voltage regulation
• Wearable technology with strict space and power constraints
• Embedded systems utilizing ceramic output capacitors for stability

Procurement Notes

Verify the specific suffix 'A' indicates the high-accuracy version with ±0.5% output voltage tolerance, distinct from standard variants. Confirm the 'DTPU' designation corresponds to the 4-DFN 1x1 mm package type. Ensure compatibility with the required 0.47 µF minimum ceramic output capacitor for proper loop stability. Cross-reference the manufacturer part number against official STMicroelectronics documentation to validate authenticity and revision status before integration.

Selection Notes

Select this component when a fixed 1.8 V rail is required with tight tolerance specifications. The high accuracy variant is suitable for sensitive analog or digital loads where voltage deviation must be minimized. Consider the small footprint for dense PCB layouts. Evaluate the input voltage headroom against the 200 mV typical dropout requirement under maximum load conditions to ensure continuous regulation without entering dropout mode.

Part Context

This device belongs to the LD39020 family of ultra-low quiescent current linear regulators designed for space-constrained applications. The family offers various fixed output voltages ranging from 0.8 V to 5.0 V in 50 mV steps. The LD39020 series is characterized by its ability to stabilize using only small ceramic capacitors, simplifying the bill of materials and reducing overall solution size compared to older LDO technologies requiring tantalum or electrolytic outputs.

Replacement Considerations

LD39020ATPU18R: Standard accuracy version with ±2.0% tolerance instead of ±0.5%. LD39020DTPU18R: Standard accuracy version in the same package. LD39020ADTPU28R: Same accuracy but different 2.8 V output voltage.