LDS3985PM33R

Overview

The LDS3985PM33R is a fixed-output linear voltage regulator manufactured by STMicroelectronics. It provides a stable 3.3V output with a maximum current capacity of 300mA. The device operates within an input voltage range of 2.5V to 6V and features a typical dropout voltage of 150mV at full load. Key electrical specifications include a quiescent current of 150µA and power supply rejection ratios ranging from 50dB to 55dB across frequencies of 1kHz to 10kHz. The component supports shutdown control and includes protection against overcurrent and thermal overload, ensuring reliable operation in surface-mount applications.

Feature Summary

• Provides a fixed 3.3V output with up to 300mA continuous current capability
• Features low dropout performance for efficient voltage regulation
• Includes shutdown control functionality for power management
• Integrates overcurrent and thermal overload protection mechanisms

Applications

• Portable battery-powered electronic devices requiring stable 3.3V logic levels
• Embedded systems utilizing ceramic or tantalum output capacitors
• Low-noise analog circuit power supplies
• General-purpose linear regulation in compact surface-mount designs

Procurement Notes

Verify the specific package variant, as the PM33R designation corresponds to the 6-DFN (3x3mm) form factor. Confirm availability status, as this component may be obsolete or discontinued depending on the supplier's inventory timestamp. Ensure compatibility with RoHS3 standards if required by your manufacturing process. Cross-reference the exact suffix with official STMicroelectronics documentation to confirm pinout and thermal pad requirements before finalizing procurement orders.

Selection Notes

Select this regulator when a fixed 3.3V rail is needed with moderate current demands up to 300mA. It is suitable for designs prioritizing low quiescent current and compact footprint via the DFN package. Consider the input voltage range limits and ensure the dropout characteristics meet the system's efficiency requirements. Verify that the application environment stays within the specified operating temperature range and that appropriate decoupling capacitors are used for stability.

Part Context

This component belongs to the LDS3985 family of low-dropout linear regulators from STMicroelectronics. The family offers various fixed output voltages and packaging options to suit different design constraints. The LDS3985 series is characterized by its ability to drive loads with both ceramic and high-quality tantalum capacitors, providing flexibility in filter design while maintaining stability and performance across varying load conditions.

Replacement Considerations

Direct substitutes include other LDS3985 variants with matching output voltages and packages, such as the LDS3985PU28R for 2.8V output in a similar DFN format. Check for updated revisions or pin-compatible alternatives from STMicroelectronics if the PM33R is obsolete. Ensure any replacement maintains the same 300mA current rating and 3.3V output specification.