Texas Instruments LP2975AIMM-12/NOPB

Overview

LP2975AIMM-12/NOPB 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 12 V output with ±1.5% accuracy (A-grade), supports input voltages from 1.8 V to 24 V, draws only 180 µA quiescent current at 5 V input, and features built-in overtemperature and current-limit protection - used in post-regulation of switching converters and high-reliability industrial power rails.

For engineers reviewing the LP2975AIMM-12/NOPB datasheet, LP2975AIMM-12/NOPB pinout, LP2975AIMM-12/NOPB application, or LP2975AIMM-12/NOPB equivalent, key selection considerations include gate drive capability (1.3 mA sourcing / 1.1 mA sinking), 57 mV current-sense threshold for precise external FET protection, programmable output via feedback divider, shutdown current <1 µA, and VSSOP-8 package compatibility with high-density PCB layouts.

Technical Context

The LP2975AIMM-12/NOPB operates as a voltage-mode error amplifier with internal 1.24 V bandgap reference and open-loop gain >5000 V/V, enabling tight line/load regulation (e.g., 0.03% line regulation at 5 A). Its COMP pin provides direct access to the error amplifier output for loop compensation, while the GATE pin delivers rail-to-rail drive to the external P-FET's gate with 1.3 mA sourcing and 1.1 mA sinking capability.

It implements overcurrent protection using a dedicated current-limit (CL) pin with fixed 57 mV threshold, requiring only a single sense resistor (RSC) in series with VIN. Thermal shutdown activates at ~150°C junction temperature, and the ON/OFF pin offers logic-level enable control with 0.87 V turn-on threshold and <1 µA bias current.

Key Specifications

Pinout & Package

VSSOP-8 (Package DGK0008A), 3.0 mm × 3.0 mm, 0.65 mm pitch, thermally enhanced exposed pad (pin 8 = GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2940CT-12/NOPB, LP2975AIMM-12/NOPB supports >5× higher current and user-defined dropout via FET selection; compared with TPS7A4701RGWR, it trades integration for scalability - enabling 6 A+ designs with optimized thermal management using TO-220/TO-3 FETs.

Availability

LP2975AIMM-12/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, automotive body control modules, and telecom infrastructure equipment requiring stable component supply, long-lifecycle support, and extended-temperature operation.

Supply support for LP2975AIMM-12/NOPB 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 technologies with emphasis on reliability, longevity, and industrial-grade qualification.

The LP2975AIMM-12/NOPB belongs to TI's high-current linear regulator controller product line, designed specifically for applications demanding scalable, thermally robust, and precision-regulated DC power beyond the limits of monolithic LDOs.

FAQ

What is the minimum input-to-output voltage required for LP2975AIMM-12/NOPB to maintain regulation?

The minimum input-to-output voltage (dropout) for LP2975AIMM-12/NOPB is not fixed - it depends on the R_DS(ON) of the selected external P-FET and the current-limit sense resistor RSC. For example, with NDP6020P (R_DS(ON) = 32 mΩ @ V_GS = −10 V) and RSC = 12 mΩ at 5 A load, measured dropout is 323 mV. The formula is V_DROPOUT = I_LOAD × (R_DS(ON) + RSC).

Can LP2975AIMM-12/NOPB be used to generate an output voltage other than 12 V?

Yes - LP2975AIMM-12/NOPB is inherently adjustable via its FB pin. Although the "12" in the part number denotes factory-trimmed 12 V versions, the device uses an internal 1.24 V reference and supports custom outputs (e.g., 5 V, 3.3 V, or 1.5 V) using an external resistor divider. Reference Design #2 confirms 3 V operation; Design #3 achieves 1.5 V at 6 A.

Does LP2975AIMM-12/NOPB require an external compensation network?

Yes - LP2975AIMM-12/NOPB requires external compensation via the COMP pin to ensure loop stability. The recommended network is typically a series RC (e.g., 10 kΩ + 100 pF) from COMP to GND, with optional feed-forward capacitor from COMP to GATE to counteract FET gate capacitance phase lag. Stability depends on output capacitor ESR, value, and FET selection - insufficient COUT causes ringing or oscillation (see Figures 19–20).

What is the purpose of the NC pin (Pin 6) on LP2975AIMM-12/NOPB?

Pin 6 on LP2975AIMM-12/NOPB is Not Connected (N/C) - it has no internal bond wire or circuit connection. TI's datasheet explicitly states "Device Pin 6 (N / C) has no internal connection." It should be left unconnected or tied to GND for mechanical stability and EMI reduction; floating is acceptable but not preferred in high-noise environments.

How does the current-limit function work on LP2975AIMM-12/NOPB?

The current-limit function on LP2975AIMM-12/NOPB monitors voltage across an external sense resistor (RSC) placed between VIN and the P-FET source. When the voltage at the CL pin reaches the internal 57 mV threshold, the controller reduces gate drive to fold back output current. RSC is calculated as RSC = 57 mV / I_SC; for a 5 A limit, RSC = 11.4 mΩ. This method avoids added dropout and enables precise, temperature-stable current limiting.