Texas Instruments LP3874EMPX-3.3/NOPB

Overview

LP3874EMPX-3.3/NOPB from Texas Instruments is a 3.3-V, 0.8-A ultra-low-dropout linear regulator in DDPAK/TO-263-5 package, featuring 240 mV dropout at full load, ±1.5% output voltage accuracy, and integrated SENSE pin for remote load regulation. It delivers stable microprocessor core power with fast transient response and operates across −40°C to +125°C junction temperature.

For engineers reviewing the LP3874EMPX-3.3/NOPB datasheet, LP3874EMPX-3.3/NOPB pinout, LP3874EMPX-3.3/NOPB application, or LP3874EMPX-3.3/NOPB equivalent, key selection criteria include dropout performance at 0.8 A, SENSE-enabled remote sensing capability, shutdown quiescent current (10 nA), thermal protection behavior, and compatibility with low-ESR tantalum output capacitors.

Technical Context

The LP3874EMPX-3.3/NOPB uses a CMOS-based PMOS pass element enabling ultra-low dropout and load-independent quiescent current. Its internal error amplifier compares either the OUT pin (LP3871) or SENSE pin (LP3874) voltage against a precision bandgap reference to regulate output.

It integrates active overcurrent limiting with thermal foldback, an open-drain ERROR flag asserting when VOUT drops >10% below nominal, and a logic-controlled shutdown input with 25 µs turn-on delay. The SENSE pin enables Kelvin-sense feedback for improved DC load regulation at remote points.

Key Specifications

Pinout & Package

LP3874EMPX-3.3/NOPB is housed in a thermally enhanced 5-pin DDPAK/TO-263 package (10.16 mm × 8.42 mm), with exposed thermal pad soldered to PCB copper for optimal heat dissipation (R_θJC(bot) = 1°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3874EMPX-3.3/NOPB, TSS721AIPW trades current capability and sensing for lower cost and simpler layout, while TPS7A4701RGWR offers wider voltage range and higher current at the expense of integrated diagnostics and optimized 3.3-V efficiency.

Availability

LP3874EMPX-3.3/NOPB is available at Aetrix Electronics and suitable for microprocessor core power, GTL bus termination, and battery-powered instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for LP3874EMPX-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 designing analog ICs, embedded processors, and system solutions for industrial, automotive, and communications markets.

The LP387x series was developed specifically for high-efficiency, low-noise linear regulation in space-constrained, thermally demanding applications where fast transient response and ultra-low dropout are mandatory.

FAQ

What is the minimum input voltage required for LP3874EMPX-3.3/NOPB to maintain regulation?

The minimum input voltage for LP3874EMPX-3.3/NOPB is the sum of its nominal output voltage (3.3 V) and dropout voltage. At 0.8 A, dropout is typically 240 mV, so VIN(min) = 3.54 V. However, the absolute minimum operating VIN is 2.5 V per specifications - meaning LP3874EMPX-3.3/NOPB will not regulate below 3.54 V under full load, though it may operate at reduced current if VIN ≥ 2.5 V.

How should the SENSE pin be connected in LP3874EMPX-3.3/NOPB for optimal performance?

For optimal performance, the SENSE pin of LP3874EMPX-3.3/NOPB must be connected directly to the load's power input node (e.g., CPU VDD pin) using a dedicated, low-impedance trace - not shared with the OUT-to-load path. If remote sensing is unused, SENSE must be shorted to OUT on the PCB. Leaving SENSE floating will cause regulation failure and potential output instability.

Does LP3874EMPX-3.3/NOPB require an external pullup resistor on the ERROR pin?

Yes, LP3874EMPX-3.3/NOPB requires an external 10-kΩ pullup resistor from the ERROR pin to VIN. The ERROR pin is open-drain and cannot drive high actively. Without this pullup, the flag remains undefined. If the ERROR function is unused, the pin must be connected directly to GND - not left floating - to prevent leakage-induced noise coupling.

Can LP3874EMPX-3.3/NOPB be used with ceramic output capacitors?

LP3874EMPX-3.3/NOPB is stable with ceramic output capacitors ≥10 µF, provided their ESR falls within the 100 mΩ–4 Ω stable region shown in Figure 13 of the datasheet. X7R/X5R dielectrics are recommended; Z5U/Y5V types are discouraged due to severe capacitance loss with bias voltage and temperature. Layout must minimize trace inductance between OUT, GND, and capacitor pads.

What thermal derating applies to LP3874EMPX-3.3/NOPB in a standard 2-layer PCB layout?

In a standard 2-layer PCB with 1-in² 2-oz copper pour under the DDPAK thermal pad, LP3874EMPX-3.3/NOPB's R_θJA is ~40.3°C/W. At 25°C ambient and 0.8 A load with 3.54 V input, power dissipation is ~192 mW, resulting in ~8°C junction rise - well within the 125°C limit. No derating is needed below 85°C ambient; above that, maximum load current must be reduced per thermal calculations using R_θJA and actual board layout.