Texas Instruments LP3872EMP-2.5/NOPB

Overview

LP3872EMP-2.5/NOPB from Texas Instruments is a 1.5-A ultra-low-dropout linear regulator in SOT-223 package, delivering fixed 2.5 V output with ±1.5% accuracy at room temperature, 38 mV dropout at 150 mA, and 10 nA shutdown quiescent current. It serves as a primary power supply for low-voltage microprocessors and GTL bus terminators where fast load transient response and minimal input-output differential are critical.

For engineers reviewing the LP3872EMP-2.5/NOPB datasheet, LP3872EMP-2.5/NOPB pinout, LP3872EMP-2.5/NOPB application, or LP3872EMP-2.5/NOPB equivalent, key selection criteria include verified 2.5 V output tolerance, ERROR flag functionality (active-low at −10% VOUT), thermal shutdown behavior, and SOT-223 package compatibility with 6.50 mm × 3.56 mm PCB footprint.

Technical Context

The LP3872EMP-2.5/NOPB uses a CMOS-based PMOS pass transistor architecture enabling load-independent quiescent current and ultra-low dropout performance. Its internal error amplifier drives the gate of the PMOS element to maintain regulation under rapid load steps up to 1.5 A DC.

It integrates an open-drain ERROR flag that asserts low when output voltage falls ≥10% below nominal (2.25 V), with 5% hysteresis, and requires external 10-kΩ pullup. Shutdown is controlled via CMOS-compatible SD pin with 20 µs turnoff delay and 25 µs turnon delay.

Key Specifications

Pinout & Package

LP3872EMP-2.5/NOPB is housed in a 5-pin SOT-223 package (6.50 mm × 3.56 mm body) with exposed thermal pad on the bottom side for enhanced heat dissipation. The package supports surface-mount assembly and provides RθJA = 65.2°C/W in standard JEDEC layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-dropout linear regulator applications.

Compared with LP3872EMP-2.5/NOPB, TSS721AIPW offers lower BOM count but forfeits system-level fault detection, while TPS7A4701RGWR trades current capability and integrated diagnostics for superior noise performance and output adjustability - making LP3872EMP-2.5/NOPB optimal for deterministic 2.5 V digital power with built-in supervision.

Availability

LP3872EMP-2.5/NOPB is available at Aetrix Electronics and suitable for microprocessor core supplies, GTL bus terminators, SCSI termination circuits, and battery-powered instrumentation requiring stable component supply and long-term production continuity.

Supply support for LP3872EMP-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 headquartered in Dallas, Texas, specializing in analog and embedded processing technologies with broad industrial, automotive, and communications product portfolios.

The LP387x series was designed specifically for high-current, ultra-low-dropout applications in space-constrained digital systems - targeting microprocessor I/O rails, bus terminators, and portable equipment where efficiency, precision, and integrated fault signaling are essential.

FAQ

What is the minimum input voltage required for LP3872EMP-2.5/NOPB to regulate at 2.5 V?

The LP3872EMP-2.5/NOPB requires a minimum input voltage equal to VOUT + VDROPOUT. At 1.5 A load, its dropout is 380 mV, so VIN must be ≥2.88 V to maintain regulation. However, the absolute minimum specified VIN is 2.5 V - meaning it can sustain 2.5 V output only at light loads where dropout remains ≤0 V, per datasheet Section 6.3. For full 1.5 A operation, 2.88 V is the practical lower limit.

Does LP3872EMP-2.5/NOPB require an external sense resistor or feedback network?

No, LP3872EMP-2.5/NOPB is a fixed-output regulator with internally trimmed 2.5 V reference and does not use external resistors for feedback. It has no SENSE pin - that feature is exclusive to the LP3875 variant. The LP3872EMP-2.5/NOPB regulates voltage solely at the OUT pin, so PCB trace resistance between OUT and load introduces direct error proportional to load current.

Can the ERROR pin of LP3872EMP-2.5/NOPB drive a microcontroller GPIO directly?

Yes, the ERROR pin is an open-drain output capable of sinking up to 1 mA. When pulled high with a 10-kΩ resistor to 3.3 V or 5 V, it delivers a clean logic-low signal (<0.1 V) at VOUT ≤2.25 V. This allows direct connection to most MCU GPIOs configured as interrupt inputs, provided the MCU's input leakage and threshold levels align with the 10-kΩ pullup voltage divider.

What thermal derating applies to LP3872EMP-2.5/NOPB in SOT-223 package at 1.5 A?

In standard JEDEC layout, LP3872EMP-2.5/NOPB has RθJA = 65.2°C/W. At 1.5 A with VIN = 3.3 V, power dissipation is (3.3 − 2.5) × 1.5 = 1.2 W. This yields ΔT = 1.2 × 65.2 ≈ 78°C rise above ambient. With TJ-MAX = 125°C, maximum safe ambient is ~47°C - requiring heatsinking, airflow, or reduced VIN/IOUT for higher-temperature operation.

Is LP3872EMP-2.5/NOPB compatible with ceramic output capacitors?

Yes, LP3872EMP-2.5/NOPB supports ceramic output capacitors, but only X7R or X5R dielectrics are recommended due to stable capacitance vs. voltage/temperature. Z5U/Y5V types are unsuitable - they can lose >60% capacitance at rated voltage, risking instability. Minimum 10 µF value applies, and ESR must remain between 100 mΩ and 4 Ω, which modern low-ESR ceramics satisfy when properly selected.