LP2981IM5-4.0

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The LP2981IM5-4.0 is a fixed positive single-output low-dropout (LDO) voltage regulator manufactured by National Semiconductor, now part of Texas Instruments. It provides a fixed output voltage of 4.0 V with a maximum dropout voltage of 0.375 V at rated load current. The device supports an input voltage range from 4 V to 16 V and delivers up to 100 mA of output current. It is housed in a 5-terminal SOT-23 package (PDSO5). The regulator operates within a junction temperature range of -40°C to 125°C.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Fixed positive output voltage regulation
• Low dropout voltage capability for efficient power management
• Integrated enable control feature
• Built-in overcurrent and thermal protection

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• Battery-powered portable electronic devices
• Cellular phones and wireless communication equipment
• Personal digital assistants (PDAs)
• Laptop computers and peripheral circuits

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify the manufacturer status as National Semiconductor was acquired by Texas Instruments. Confirm the specific suffix indicates the standard lead-free version if required. Check for availability of the /NOPB variant which denotes non-halogen/lead-free compliance. Ensure the package type matches the design requirements for surface mount assembly.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this component when a stable 4.0 V supply is needed from a higher voltage rail with minimal voltage loss. The 100 mA output current suits low-power applications. Consider the SOT-23-5 package for space-constrained designs. Verify that the input voltage remains above the minimum requirement of 4 V while accounting for dropout conditions under load.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

This device belongs to the LP2981 series of LDO regulators known for their low noise and high power supply rejection ratio. The series includes various fixed output voltages and packages. The IM5 designation specifically refers to the SOT-23-5 package variant. This family is widely used in consumer electronics requiring efficient linear regulation.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

LP2981IM5-4.0/NOPB is the direct lead-free equivalent. LP2981IM5X-4.0 may be available as a tape-and-reel variant. Cross-reference with other LP2981 variants for pin-compatible alternatives if different output voltages or packaging options are needed.