LP2975IMM-3.3

Overview

The LP2975IMM-3.3 is a MOSFET LDO Driver/Controller manufactured by Texas Instruments, designed to drive external P-channel FETs for high-current regulation. It operates within an input supply voltage range of 1.8V to 24V and features a typical quiescent current of 180 µA at VIN = 5V. The device provides a standard output voltage setting of 3.3V with a precision accuracy of 1.5% (A Grade) or 2.5% (Standard Grade). It includes built-in overtemperature protection and a low-power shutdown input that draws less than 1 µA. The controller utilizes a 57 mV current limit detection threshold to minimize dropout voltage.

Feature Summary

• Provides precise output voltage regulation using an external P-FET and minimal components
• Features ultra-low quiescent current consumption and a dedicated low-power shutdown mode
• Integrates built-in current limit amplifier and overtemperature protection circuitry

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 grade suffix (e.g., 'I' for Industrial or 'AI' for Automotive/Industrial) when ordering, as performance specifications vary between standard and A-grade versions. Confirm the package type matches the design requirements, as the LP2975 family includes various surface-mount options. Ensure the selected external P-FET meets the required voltage and current ratings for the intended application.

Selection Notes

Select the LP2975IMM-3.3 when designing linear regulators requiring high efficiency and low dropout characteristics. This component is suitable for applications needing programmable output voltages via external dividers or fixed 3.3V outputs. Consider the thermal management requirements of the external pass transistor, as the controller does not dissipate significant power itself but relies on proper heatsinking of the FET.

Part Context

The LP2975 series serves as a versatile controller for building custom high-current LDO regulators. By utilizing an external P-channel MOSFET, designers can achieve flexible voltage and current capabilities beyond standard integrated regulator limits. The device simplifies the design process by integrating essential control loops, protection mechanisms, and reference voltage generation into a compact package.

Replacement Considerations

LP2975AIMM-3.3/NOPB

FAQ

How is the output voltage determined for the LP2975IMM-3.3?

The LP2975IMM-3.3 is internally trimmed to provide a standard 3.3V output. Alternatively, the output voltage can be programmed to other values using an external resistor divider connected to the feedback pin.

What is the function of the ON/OFF pin?

The ON/OFF pin controls the state of the regulator. Applying a voltage above the threshold turns the output on, while pulling it below the threshold activates the low-power shutdown mode, reducing quiescent current to less than 1 µA.