LD2985BM25R

Overview

The LD2985BM25R is a fixed-output low-dropout linear voltage regulator manufactured by STMicroelectronics. It provides a stable 2.5 V output with a maximum load current of 150 mA. The device operates within an input voltage range up to 16 V and features an ultra-low dropout voltage, specified as 280 mV at full load and 7 mV at light loads. Quiescent current is typically 2 mA under load and drops below 1 μA in sleep mode when the inhibit pin is activated. The component includes logic-controlled electronic shutdown via a TTL-compatible pin, internal thermal and current limiting, and low output noise of 30 μVrms with an external bypass capacitor. It is housed in a compact SOT-23-5L package and supports an operating temperature range from -40 °C to +125 °C.

Feature Summary

• Ultra-low dropout voltage operation suitable for battery-powered systems
• Logic-controlled electronic shutdown with TTL-compatible inhibit function
• Low output noise performance with external bypass capability
• Integrated thermal and current protection limits

Applications

• Cellular phones
• Palmtop laptop computers
• Personal digital assistants (PDA)
• Camcorders and cameras

Procurement Notes

Verify that the specific part number LD2985BM25R corresponds to the 2.5 V fixed output variant within the LD2985 series. Confirm the package type is SOT-23-5L and check for RoHS compliance status if required. Ensure the supplier documentation matches the STMicroelectronics datasheet specifications for quiescent current and dropout characteristics. Validate that the inhibit pin functionality is supported in the specific revision being procured.

Selection Notes

Select this component when a stable 2.5 V rail is required with minimal voltage drop across the regulator. It is appropriate for designs prioritizing low power consumption in standby modes due to the sub-1 μA sleep current. Consider the 150 mA output limit for load requirements and ensure the application benefits from the low noise profile provided by the bypass pin feature.

Part Context

The LD2985 series comprises very low drop and low noise voltage regulators designed for portable electronics. This family offers various fixed output voltages including 1.8 V, 2.5 V, 2.8 V, 3.0 V, 3.1 V, 3.3 V, and 5 V. The BM25R suffix indicates the 2.5 V version in the SOT-23-5L package. These regulators are engineered for high efficiency and stability with small ceramic capacitors.

Replacement Considerations

Publicly confirmed substitute part numbers include LD2985BM30R for a 3.0 V output variant and LP2981-33DBVR from Texas Instruments for a 3.3 V alternative. Verify output voltage compatibility before substitution.