LD2979M33TR

Overview

The LD2979M33TR is a fixed-output low-dropout voltage regulator from STMicroelectronics, providing a nominal output of 3.3 V with a maximum load current of 50 mA. It operates within an input voltage range up to 16 V and maintains stability using only a 1 µF output capacitor. The device features a logic-controlled inhibit pin for power management, allowing the system to enter a standby mode with zero quiescent current when disabled. It includes internal protections against overcurrent and thermal overload.

Feature Summary

• Logic-controlled electronic shutdown function enables local board sections to enter standby mode, reducing total power consumption.
• Very low dropout voltage ensures efficient regulation under minimal input-to-output voltage differentials.
• Internal current limiting and thermal protection mechanisms safeguard the device during fault conditions.

Applications

• Battery-powered systems requiring low noise and high efficiency
• Low-power embedded applications needing precise voltage regulation
• Portable devices utilizing logic-controlled power management

Procurement Notes

Verify the specific order code LD2979M33TR against official STMicroelectronics documentation to confirm the 3.3 V fixed output variant. Ensure compatibility with SOT23-5L surface-mount assembly requirements. Confirm that the application circuit utilizes a minimum 1 µF output capacitor to guarantee stability across the specified operating temperature range.

Selection Notes

Select this component for designs prioritizing low quiescent current and minimal external component count. The fixed 3.3 V output eliminates the need for external resistors. Consider the SOT23-5L package constraints for PCB layout. Verify that the input voltage remains within the 16 V absolute maximum rating while accounting for dropout voltage variations at full load.

Part Context

This part belongs to the LD2979 series of very low drop regulators manufactured by STMicroelectronics. The series offers multiple fixed output voltages including 3.0 V, 3.8 V, and 5.0 V variants. All members share the same SOT23-5L package and feature set, differing primarily in their regulated output levels.

Replacement Considerations

Other LD2979xx variants (LD2979M30TR, LD2979M38TR, LD2979M50TR) are pin-compatible but provide different fixed output voltages. Direct substitution requires verifying that the alternative output voltage matches the target circuit requirements.