Texas Instruments LP2975IMMX-5.0

Overview

LP2975IMMX-5.0 from Texas Instruments is a high-current LDO controller IC that drives an external P-channel MOSFET to implement ultra-low-dropout linear regulation. It delivers 5.0 V output with ±1.5% accuracy (A grade), supports input voltages from 1.8 V to 24 V, draws only 180 µA typical quiescent current at VIN = 5 V, and features built-in overtemperature and current-limit protection - used in high-current post-regulation for switching converters.

For engineers reviewing the LP2975IMMX-5.0 datasheet, LP2975IMMX-5.0 pinout, LP2975IMMX-5.0 application, or LP2975IMMX-5.0 equivalent, key selection criteria include its gate drive capability (1.3 mA sourcing / 1.1 mA sinking), 57 mV current-sense threshold, shutdown current <1 µA, VSSOP-8 package footprint, and compatibility with logic-level P-FETs for sub-500 mV dropout at multi-amp loads.

Technical Context

The LP2975IMMX-5.0 operates as a voltage-mode error amplifier with internal 1.24 V bandgap reference and open-loop gain >5000 V/V, enabling precise feedback control of external P-FET gate voltage. Its COMP pin provides direct access to the error amplifier output for loop compensation and feed-forward capacitor integration.

It implements programmable current limiting via an external sense resistor tied to the CL pin with fixed 57 mV threshold, and includes thermal shutdown activation at ~150°C junction temperature. The ON/OFF pin accepts TTL/CMOS-compatible logic levels (0.4 V low, 0.87 V high) for enable/disable control with 34 µA bias current.

Key Specifications

Pinout & Package

VSSOP-8 (Package Number DGK0008A), 3.0 mm × 3.0 mm, 0.65 mm pitch, exposed thermal pad - optimized for compact, thermally efficient PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO controller applications.

Compared with LM2975IMMX-5.0 and TPS7A4700RGWR, the LP2975IMMX-5.0 uniquely balances high-current scalability (via external P-FET), wide input range (up to 24 V), and extended temperature qualification - making it the sole choice for ruggedized 5 A+ linear regulation where thermal and environmental margins are critical.

Availability

LP2975IMMX-5.0 is available at Aetrix Electronics and suitable for high-current post-regulation, industrial 24 V linear supplies, current-limited hot-swap switches, and FPGA/microcontroller core I/O power requiring stable component supply across extended temperature ranges.

Supply support for LP2975IMMX-5.0 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions with deep expertise in power management and precision analog design.

The LP2975 product line was engineered specifically for high-current, low-dropout linear regulation using external P-FETs - targeting applications needing >3 A output, wide input voltage flexibility, and robust thermal/current protection without integrated pass devices.

FAQ

What is the function of the COMP pin on the LP2975IMMX-5.0?

The COMP pin on the LP2975IMMX-5.0 provides direct access to the output of the internal error amplifier. It is used to connect external compensation components (e.g., RC network) to stabilize the control loop when driving high-capacitance or high-gate-charge P-FETs. This pin enables tuning of phase margin and transient response - critical for maintaining stability with varying output capacitance and load conditions in LP2975IMMX-5.0-based designs.

Does the LP2975IMMX-5.0 integrate the pass transistor?

No, the LP2975IMMX-5.0 does not integrate the pass transistor. It is a controller IC designed to drive an external P-channel MOSFET, which serves as the linear pass element. This architecture allows designers to select FETs optimized for specific current, voltage, thermal, and RDS(ON) requirements - enabling LP2975IMMX-5.0 to support output currents exceeding 5 A while maintaining low dropout and thermal efficiency.

What is the minimum input-to-output voltage required for regulation with the LP2975IMMX-5.0?

The minimum input-to-output voltage (dropout) for the LP2975IMMX-5.0 is determined by the RDS(ON) of the selected external P-FET and the current-sense resistor RSC: VDROPOUT = ILOAD × (RDS(ON) + RSC). In a verified 5 V/5 A reference design using the NDP6020P FET, LP2975IMMX-5.0 achieves 323 mV dropout - confirming its suitability for ultra-low-dropout applications where headroom is constrained.

Can the LP2975IMMX-5.0 be used to generate an adjustable output voltage?

Yes, the LP2975IMMX-5.0 supports adjustable output voltages via an external resistor divider on the FB pin. While the "-5.0" suffix indicates factory-trimmed 5.0 V output, the device's feedback architecture allows reconfiguration - for example, Design #2 in the datasheet demonstrates 3.0 V output using a 237 kΩ resistor. The LP2975IMMX-5.0 maintains regulation accuracy and stability across such adjustments when compensation is properly applied.

How does the current-limit feature of the LP2975IMMX-5.0 work?

The LP2975IMMX-5.0 implements current limiting by monitoring voltage across an external sense resistor (RSC) connected between VIN and the source of the P-FET. Its CL pin detects when this voltage reaches 57 mV - the fixed internal threshold - and reduces gate drive to hold output current constant. This provides accurate, resistor-programmable overcurrent protection without additional ICs, directly protecting both load and FET in LP2975IMMX-5.0-based power stages.