LP2975IMM-3.3/NOPB

Overview

The LP2975IMM-3.3/NOPB is a MOSFET LDO Driver/Controller manufactured by Texas Instruments, housed in an 8-lead VSSOP surface-mount package. It provides a standard output voltage of 3.3V with a specified accuracy of 1.5% for the 'A' grade and 2.5% for the standard grade. The device operates within an input supply voltage range of 1.8V to 24V and supports a junction temperature range from -40°C to +125°C. Typical quiescent current is 180 µA at VIN = 5V, while shutdown current is less than 1 µA. Key electrical parameters include a 57 mV current limit sense threshold and a gate drive current capability of up to 3.5 mA sourcing.

Feature Summary

• Integrates a high open-loop gain amplifier and trimmed internal bandgap reference for precise regulation and ripple rejection.
• Features a low-power shutdown input that reduces operating current to under 1 µA.
• Includes built-in current limit amplification and overtemperature protection mechanisms.
• Enables user-selectable dropout voltage through external P-FET sizing.

Applications

• High-current 5V to 3.3V regulator designs
• Post-regulator stages for switching converters
• Current-limited power distribution switches

Procurement Notes

Verify the specific suffix 'NOPB' indicates lead-free compliance and confirms the manufacturer as Texas Instruments rather than National Semiconductor. Ensure the ordering code matches the required grade ('A' for 1.5% or standard for 2.5%) and confirm the package type is VSSOP-8. Cross-reference the datasheet revision SNVS006F for the most current electrical specifications.

Selection Notes

Select this controller when designing custom high-current linear regulators using external P-channel MOSFETs. It is suitable for applications requiring ultra-low dropout characteristics defined by the external FET's RDS(ON). Consider the 180 µA typical quiescent current for power-sensitive designs and ensure the external FET selection accounts for the limited gate drive current capabilities of the controller.

Part Context

This component belongs to the LP2975 family of MOSFET LDO drivers/controllers. The LM2975AI variant represents the higher precision 'A' grade version, while the base LP2975 covers standard grades. The device allows designers to build wide variety of linear regulators by pairing the controller with virtually any compatible P-channel MOSFET.

Replacement Considerations

LP2975IMM-5.0/NOPB

FAQ

How is the dropout voltage determined for this controller?

The dropout voltage is user-selectable and depends on the maximum load current multiplied by the RDS(ON) of the external P-FET used in the design.

What is the function of the RSET resistor value of 39.9k?

The 39.9k resistor value corresponds to the internal feedback network configuration for the 3.3V standard output voltage version of the device.