Texas Instruments LP3872EMPX-3.3/NOPB

Overview

LP3872EMPX-3.3/NOPB from Texas Instruments is a 1.5-A ultra-low-dropout linear regulator in SOT-223 package, delivering fixed 3.3-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 DSPs requiring fast transient response and stable regulation under varying load conditions.

For engineers reviewing the LP3872EMPX-3.3/NOPB datasheet, LP3872EMPX-3.3/NOPB pinout, LP3872EMPX-3.3/NOPB application, or LP3872EMPX-3.3/NOPB equivalent, key selection criteria include its 3.3-V fixed output, ERROR flag functionality (active-low at −10% VOUT), SOT-223 thermal performance (RθJA = 65.2°C/W), and CMOS-based low-IQ operation independent of load.

Technical Context

The LP3872EMPX-3.3/NOPB uses a PMOS pass element architecture enabling ultra-low dropout voltage and reverse-current protection via an integrated parasitic diode rated for 200 mA DC. Its error amplifier and reference circuitry are implemented in CMOS, ensuring ground current remains stable across load (6 mA typical at 1.5 A) and temperature (−40°C to 125°C).

It integrates dedicated shutdown control (SD pin, 0.3 V threshold) and an open-drain ERROR flag that asserts low when output drops >10% below nominal - with 5% hysteresis and 1 µs reset delay. Unlike the LP3875, it lacks SENSE functionality and relies on local OUT-pin regulation only.

Key Specifications

Pinout & Package

SOT-223 (5-pin) package with exposed thermal pad (6.50 mm × 3.56 mm); pin 3 is GND and serves as primary thermal path to PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR and MCP1826T-3302E/DB, the LP3872EMPX-3.3/NOPB uniquely combines 3.3-V fixed output, ERROR flag, shutdown control, and sub-400-mV dropout in SOT-223 - making it optimal for space-constrained, fault-aware 3.3-V systems where input headroom is limited.

Availability

LP3872EMPX-3.3/NOPB is available at Aetrix Electronics and suitable for microprocessor power supplies, GTL bus terminators, and battery-powered instrumentation requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LP3872EMPX-3.3/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 specializing in analog and embedded processing technologies, with leadership in power management ICs since the 1980s.

The LP387x series was designed specifically for high-current, low-dropout applications in portable and embedded systems - emphasizing fast transient response, low quiescent current, and integrated fault signaling for robust power rail management.

FAQ

What is the dropout voltage specification for LP3872EMPX-3.3/NOPB at full 1.5-A load?

The LP3872EMPX-3.3/NOPB has a typical dropout voltage of 380 mV at 1.5-A load and 25°C, rising to 550 mV across the full −40°C to 125°C junction temperature range. This value is defined as the minimum VIN–VOUT differential required to maintain output regulation within 2% of 3.3 V. The low dropout enables operation from marginal input sources such as partially discharged Li-ion cells.

Does LP3872EMPX-3.3/NOPB support remote voltage sensing?

No, LP3872EMPX-3.3/NOPB does not support remote voltage sensing. It regulates output voltage solely at the OUT pin. The SENSE pin is absent - that functionality is exclusive to the LP3875 variant. For applications requiring regulation at the point of load, LP3872EMPX-3.3/NOPB must be placed physically close to the load, or an alternative like LP3875 should be selected.

How does the ERROR flag on LP3872EMPX-3.3/NOPB behave during shutdown?

When the SD pin of LP3872EMPX-3.3/NOPB is pulled low, the ERROR flag is forced invalid and ceases to reflect output status - consistent with its power-saving design. The ERROR pin becomes high-impedance and must be externally pulled high (e.g., with a 10-kΩ resistor) or tied to ground if unused. It only asserts low during active operation when VOUT drops >10% below 3.3 V.

What is the recommended output capacitor for stable operation of LP3872EMPX-3.3/NOPB?

LP3872EMPX-3.3/NOPB requires a minimum 10-µF output capacitor located ≤1 cm from the device, connected directly between OUT and GND with dedicated low-impedance traces. Tantalum capacitors are recommended due to their stable ESR profile (100 mΩ–4 Ω); ceramic capacitors may be used if X7R/X5R dielectric and sufficient voltage derating are applied to maintain ≥10 µF across temperature and bias.

Can LP3872EMPX-3.3/NOPB be used with input voltages below 3.3 V?

No - LP3872EMPX-3.3/NOPB requires a minimum input voltage of 2.5 V, but practical operation below 3.338 V (3.3 V + 38 mV dropout) results in loss of regulation. At 3.3 V output, the absolute minimum functional VIN is 3.338 V at 150 mA load and rises to 3.68 V at 1.5 A. Input voltages below these thresholds cause the output to droop proportionally and trigger the ERROR flag.