Texas Instruments LP2989AIM-2.5/NOPB

Overview

LP2989AIM-2.5/NOPB from Texas Instruments is a fixed-output 2.5-V, 500-mA ultra-low-dropout linear regulator using a VIP PNP pass element, delivering 0.75% output voltage accuracy (A grade), 310 mV typical dropout at 500 mA, and 18 µV_RMS output noise with 10-nF bypass capacitor - deployed in notebook power rails and SMPS post-regulation.

For engineers reviewing the LP2989AIM-2.5/NOPB datasheet, LP2989AIM-2.5/NOPB pinout, LP2989AIM-2.5/NOPB application, or LP2989AIM-2.5/NOPB equivalent, key selection criteria include dropout performance at full load, ground current vs. load, shutdown threshold behavior, error flag hysteresis, and thermal pad handling for WSON-8 package reliability.

Technical Context

The LP2989AIM-2.5/NOPB uses a vertically integrated PNP (VIP) pass transistor architecture enabling ultra-low dropout (310 mV @ 500 mA) and low ground current (3 mA @ 500 mA). Its internal 1.23-V reference and precision feedback network achieve ±0.75% initial output tolerance and 20 ppm/°C temperature coefficient.

It integrates a dedicated error comparator with −4.8% to −6.6% output undervoltage thresholds and 2% hysteresis, plus active shutdown control with 0.18 V turn-off and 1.6 V turn-on thresholds. Thermal shutdown and foldback current limiting protect against sustained overload or short-circuit conditions.

Key Specifications

Pinout & Package

LP2989AIM-2.5/NOPB is packaged in an 8-pin WSON (NGN) with 4.00 mm × 4.00 mm body size and exposed thermal pad on bottom - requires PCB copper pad and thermal vias for junction-to-board thermal resistance of 12.0°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSS721AIPW and TPS7A2025PDBVR, LP2989AIM-2.5/NOPB uniquely combines 500-mA drive, integrated ERROR flag, and A-grade 0.75% accuracy in WSON-8 - making it optimal for mission-critical 2.5-V supplies requiring both robustness and precision.

Availability

LP2989AIM-2.5/NOPB is available at Aetrix Electronics and suitable for notebook power rails, SMPS post-regulation, wireless baseband supplies, and PDA core logic requiring stable component supply with long-term manufacturability and TI's standard 10-year product longevity commitment.

Supply support for LP2989AIM-2.5/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 company designing analog ICs, embedded processors, and system solutions for industrial, automotive, and personal electronics markets.

The LP2989AIM-2.5/NOPB belongs to TI's precision LDO regulator family targeting battery-powered and noise-sensitive applications - engineered for ultra-low dropout, micropower operation, and high DC accuracy without external components.

FAQ

What is the maximum input voltage rating for LP2989AIM-2.5/NOPB?

The LP2989AIM-2.5/NOPB has an absolute maximum input voltage of 16 V, with recommended operating range from 2.1 V to 16 V. Exceeding 16 V may cause permanent damage. The device includes internal protection against input-to-output reverse bias, but external clamping is required if the output is forced above the input supply.

Does LP2989AIM-2.5/NOPB require an external bypass capacitor to achieve its specified 18 µV_RMS noise?

Yes - LP2989AIM-2.5/NOPB achieves 18 µV_RMS output noise (100 Hz–100 kHz) only when a 10-nF ceramic capacitor is connected between the BYPASS pin (Pin 1) and ground. Without this capacitor, output noise rises significantly; the bypass cap stabilizes the internal reference and reduces high-frequency noise coupling.

Can the SENSE pin of LP2989AIM-2.5/NOPB be left unconnected?

No - the SENSE pin (Pin 6) must be either connected directly to the OUTPUT pin (Pin 5) for local regulation or routed to the load point for remote sensing. Leaving it floating invalidates load regulation performance and may cause instability. For most designs, tying SENSE to OUTPUT is sufficient and matches the typical application schematic.

What is the function of Pin 2 (N/C) on LP2989AIM-2.5/NOPB, and how should it be handled on the PCB?

Pin 2 on LP2989AIM-2.5/NOPB is a no-connect factory test terminal used for post-packaging calibration of output voltage accuracy. It must remain electrically floating - no PCB trace, solder mask opening, or grounding is permitted. Continuity testing or voltage application to Pin 2 risks activating internal trim circuitry and shifting V_OUT out of specification.

How does the ERROR pin on LP2989AIM-2.5/NOPB behave during undervoltage conditions?

The ERROR pin on LP2989AIM-2.5/NOPB is an open-drain output that pulls low when the regulated output drops approximately 4.8% to 6.6% below nominal 2.5 V, with 2% hysteresis. It remains high under normal regulation and asserts low within microseconds of fault onset - enabling immediate host MCU interrupt or system-level brownout response without external comparators.