Texas Instruments LP3875ESX-1.8/NOPB

Overview

LP3875ESX-1.8/NOPB from Texas Instruments is a 1.5-A ultra-low-dropout linear regulator in TO-263 (DDPAK) package, delivering fixed 1.8 V output with ±1.5% accuracy at room temperature. It operates from 2.5 V to 7 V input, achieves 380 mV dropout at full 1.5-A load, and features remote voltage sensing via SENSE pin for precision regulation at point-of-load-ideal for powering low-voltage microprocessors and DSPs.

For engineers reviewing the LP3875ESX-1.8/NOPB datasheet, LP3875ESX-1.8/NOPB pinout, LP3875ESX-1.8/NOPB application, or LP3875ESX-1.8/NOPB equivalent, key selection considerations include its 10-nA shutdown quiescent current, SENSE-enabled load regulation, thermal/overcurrent protection, and compatibility with 10-µF tantalum output capacitors meeting 100 mΩ–4 Ω ESR range.

Technical Context

The LP3875ESX-1.8/NOPB uses a CMOS-based PMOS pass element enabling ultra-low dropout and load-independent quiescent current. Its dedicated SENSE pin forms a Kelvin-sense feedback loop that actively regulates voltage at the remote load, decoupling trace resistance effects-unlike the LP3872 which regulates only at the OUT pin.

It integrates error flag monitoring (10% VOUT threshold with 5% hysteresis), active shutdown control with 25 µs turn-on delay, and internal short-circuit/thermal limiting. The device maintains 0.06% load regulation and 0.02% line regulation under nominal conditions, with ground pin current of 6 mA at 1.5-A load.

Key Specifications

Pinout & Package

LP3875ESX-1.8/NOPB is housed in a 5-pin TO-263 (DDPAK/KTT) thermally enhanced surface-mount package (10.16 mm × 8.42 mm), with exposed thermal pad tied to GND for optimal heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3875ESX-1.8/NOPB, TPS7A4700RGWR offers superior noise performance but sacrifices SENSE functionality and current capability, while LP3965ESX-1.8 reduces solution complexity and dropout voltage but eliminates critical system-monitoring features like ERROR flag and remote sensing.

Availability

LP3875ESX-1.8/NOPB is available at Aetrix Electronics and suitable for microprocessor core supplies, GTL bus terminators, DSP power management, battery-powered instrumentation, and other applications requiring stable component supply with guaranteed long-term manufacturability.

Supply support for LP3875ESX-1.8/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 designing analog ICs, embedded processors, and connectivity solutions for industrial, automotive, and consumer markets.

The LP387x product line delivers fast ultra-low-dropout linear regulators optimized for low-voltage, high-current digital loads-including microprocessors, DSPs, and memory interfaces-where precision regulation, fast transient response, and minimal quiescent power are essential.

FAQ

What is the minimum input voltage required for LP3875ESX-1.8/NOPB to maintain regulation?

The LP3875ESX-1.8/NOPB requires a minimum input voltage equal to its nominal output voltage plus dropout voltage. With a typical dropout of 380 mV at 1.5-A load, the minimum VIN is 2.18 V. However, per datasheet Section 6.3, the absolute minimum specified VIN is 2.5 V-so LP3875ESX-1.8/NOPB must be operated at ≥2.5 V input regardless of load, ensuring compliance with recommended operating conditions.

Can the SENSE pin of LP3875ESX-1.8/NOPB be left unconnected?

No-the SENSE pin of LP3875ESX-1.8/NOPB must not be left floating. If remote sensing is not used, the SENSE pin must be connected directly to the OUT pin to ensure proper regulation. Leaving it unconnected risks instability or incorrect output voltage due to undefined feedback path, as confirmed in Section 7.3.2 and Figure 13 of the SNVS227H datasheet.

Does LP3875ESX-1.8/NOPB include reverse-current protection?

LP3875ESX-1.8/NOPB does not include active reverse-current protection, but its internal PMOS pass transistor provides passive blocking: when VOUT exceeds VIN, the body diode becomes forward-biased, allowing up to 200 mA continuous or 1 A peak reverse current. Designers must limit external reverse current to these values using external circuitry if bidirectional energy flow is possible.

What output capacitor types are recommended for LP3875ESX-1.8/NOPB?

Tantalum capacitors are explicitly recommended for LP3875ESX-1.8/NOPB output stabilization due to their ideal ESR range (100 mΩ–4 Ω) and stable capacitance vs. temperature. Ceramic capacitors may be used if X7R/X5R dielectric and sufficient capacitance (≥10 µF) are selected-but Z5U/Y5V ceramics are discouraged due to severe voltage/temperature derating. Aluminum electrolytics are not recommended due to excessive ESR variation at low temperatures.

How does the ERROR flag on LP3875ESX-1.8/NOPB behave during shutdown?

When the SD pin of LP3875ESX-1.8/NOPB is pulled low to activate shutdown mode, the ERROR flag is forced invalid (high-impedance) to conserve power-as stated in Section 7.4.3 of the datasheet. The ERROR function resumes only after SD returns high and the device exits shutdown, with typical turn-on delay of 25 µs before valid flag assertion.