Texas Instruments LP3871EMP-5.0/NOPB

Overview

LP3871EMP-5.0/NOPB from Texas Instruments is a 0.8-A ultra-low-dropout linear regulator in SOT-223 package, delivering fixed 5.0 V output with ±1.5% accuracy at room temperature, 240 mV dropout at full load, and 10 nA shutdown quiescent current. It integrates ERROR flag monitoring and operates across −40°C to +125°C junction temperature for microprocessor power supplies and battery-powered systems.

For engineers reviewing the LP3871EMP-5.0/NOPB datasheet, LP3871EMP-5.0/NOPB pinout, LP3871EMP-5.0/NOPB application, or LP3871EMP-5.0/NOPB equivalent, key selection criteria include dropout voltage under 0.8-A load, ground pin current behavior, ERROR flag threshold hysteresis, SENSE pin absence (LP3871 variant), and thermal performance in SOT-223.

Technical Context

The LP3871EMP-5.0/NOPB uses a CMOS-based PMOS pass transistor architecture enabling ultra-low dropout and load-independent quiescent current. Its internal error amplifier drives the pass element with fast transient response-critical for microprocessor supply rails experiencing rapid load steps.

Unlike the LP3874, this variant lacks a SENSE pin and regulates voltage solely at the OUT pin. The ERROR flag provides open-drain status indication of >10% output undervoltage with 5% hysteresis, while shutdown is controlled via a logic-level SD input requiring external 10-kΩ pullup.

Key Specifications

Pinout & Package

SOT-223 (5-pin) package: 6.50 mm × 3.56 mm body size, thermally enhanced with exposed pad connected to GND for PCB heat sinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR and MCP1703T-5002E/MB, the LP3871EMP-5.0/NOPB uniquely balances 0.8-A delivery, 240-mV dropout, integrated ERROR flag, and 10-nA shutdown in a thermally robust SOT-223-making it optimal for space-constrained, battery-aware microprocessor systems requiring autonomous fault detection.

Availability

LP3871EMP-5.0/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 LP3871EMP-5.0/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 specializing in analog, embedded processing, and power management technologies, with decades of LDO design heritage and automotive-grade qualification expertise.

The LP387x series was engineered for high-current, low-dropout regulation in battery-powered and thermally constrained applications-emphasizing fast transient response, minimal quiescent loss, and integrated fault monitoring without external components.

FAQ

What is the minimum input voltage required for LP3871EMP-5.0/NOPB to regulate 5.0 V output?

The LP3871EMP-5.0/NOPB requires a minimum input voltage of 5.24 V under full 0.8-A load to maintain regulation, based on its 240-mV dropout specification. At lighter loads, dropout drops to 24 mV (requiring only 5.024 V), but the absolute minimum input per datasheet is 2.5 V-though operation below [VOUT + VDROPOUT] results in unregulated output. Always verify margin using worst-case dropout at target load and temperature.

Does LP3871EMP-5.0/NOPB include a remote sense (SENSE) pin?

No, LP3871EMP-5.0/NOPB does not include a SENSE pin. It is the LP3871 variant, which regulates voltage only at the OUT pin. The SENSE function is exclusive to the LP3874 family. For applications requiring remote load regulation-such as long PCB traces between regulator and FPGA core rail-LP3874 variants must be selected instead of LP3871EMP-5.0/NOPB.

How is the ERROR flag on LP3871EMP-5.0/NOPB configured and used?

The ERROR pin on LP3871EMP-5.0/NOPB is an open-drain output that pulls low when output voltage drops >10% below 5.0 V (i.e., <4.5 V), with 5% hysteresis to prevent oscillation. It requires an external 10-kΩ pullup resistor to VIN and is disabled during shutdown. This flag enables system-level brownout detection without adding a separate supervisor IC-directly interfacing with microcontroller GPIO or reset controllers.

What thermal considerations apply to LP3871EMP-5.0/NOPB in SOT-223 package?

LP3871EMP-5.0/NOPB in SOT-223 has R_θJA = 65.2°C/W. At 0.8 A and 5.0 V output with 5.5 V input (0.5 V drop), power dissipation is 0.4 W-resulting in ~26°C rise above ambient. To sustain full load at 85°C ambient, PCB copper area under the exposed pad and thermal vias to inner ground planes are essential. Derate output current if ambient exceeds 85°C or airflow is restricted.

Can LP3871EMP-5.0/NOPB be used with ceramic output capacitors?

Yes, LP3871EMP-5.0/NOPB supports ceramic output capacitors, but ESR must be ≥100 mΩ for stability per Figure 13 in the datasheet. Standard X7R/X5R ceramics often fall below this-so either add a small series resistor (e.g., 100–220 mΩ) or select specialized high-ESR ceramics. Tantalum capacitors (10 µF, 1–2 Ω ESR) are preferred for guaranteed stability without modification.