LD2979M38TR

Overview

The LD2979M38TR is a fixed-output low-dropout voltage regulator manufactured by STMicroelectronics, providing a nominal output of 3.8 V with a maximum load current of 50 mA. It operates within an input voltage range up to 16 V and features a typical dropout voltage of 400 mV at full load. The device incorporates logic-controlled electronic shutdown functionality via a dedicated inhibit pin, which must be driven above 2 V to enable operation. Designed for stability with only a 1 µF output capacitor, it maintains an operating junction temperature range from -25 °C to +125 °C.

Feature Summary

• Logic-controlled electronic shutdown function compatible with TTL levels
• Very low dropout voltage performance under load conditions
• Internal protection against thermal overload and output current limiting

Applications

• Battery-powered systems requiring low quiescent current
• Low noise power supply applications
• Local regulators enabling board-level standby modes

Procurement Notes

Verify the specific order code LD2979M38TR against official STMicroelectronics documentation to confirm the 3.8 V output variant. Ensure compatibility with SOT-23-5L surface-mount assembly requirements. Confirm that the application circuit utilizes the specified minimum capacitance for stability. Check for any environmental compliance markings such as ECOPACK on the packaging.

Selection Notes

Select this component when a fixed 3.8 V rail is required in space-constrained designs utilizing the SOT-23-5L package. It is suitable for applications needing precise voltage regulation with minimal external components. Consider the internal current and thermal limits when designing for high ambient temperatures or heavy loads near the 50 mA maximum rating.

Part Context

This part belongs to the LD2979 series of very low drop voltage regulators. The series includes variants with different fixed output voltages, including 3.0 V, 3.3 V, and 5.0 V. All members share the same SOT-23-5L package and feature set, differing primarily in their regulated output voltage levels.

Replacement Considerations

Other parts in the LD2979 family, such as LD2979M30TR (3.0 V), LD2979M33TR (3.3 V), and LD2979M50TR (5.0 V), offer identical pinouts and features but provide different fixed output voltages.