Texas Instruments LP3856ES-2.5/NOPB

Overview

LP3856ES-2.5/NOPB from Texas Instruments is a 2.5V, 3A ultra-low-dropout linear regulator in TO-263-5 package, featuring 390mV dropout at full load, ±1.5% output voltage accuracy, remote sense capability via SENSE pin, and 10nA shutdown quiescent current. It delivers stable microprocessor core power with fast transient response and ceramic capacitor compatibility.

For engineers reviewing the LP3856ES-2.5/NOPB datasheet, LP3856ES-2.5/NOPB pinout, LP3856ES-2.5/NOPB application, or LP3856ES-2.5/NOPB equivalent, key selection criteria include dropout performance at 3A, remote-sense load regulation improvement, shutdown leakage, ceramic output capacitor stability limits, and thermal derating in TO-263 packaging.

Technical Context

This CMOS-based LDO employs a PMOS pass element enabling ultra-low dropout (390mV @ 3A) and load-independent quiescent current. Its error amplifier uses the SENSE pin to regulate voltage at the remote load point, decoupling trace IR drop from regulation accuracy.

The device integrates overtemperature and overcurrent protection with foldback current limiting, and features an open-drain ERROR flag with 10% VOUT threshold hysteresis. Shutdown control is TTL/CMOS-compatible with 10nA IQ and 25µs turn-on delay.

Key Specifications

Pinout & Package

LP3856ES-2.5/NOPB is packaged in TO-263-5 (D²Pak), thermally enhanced surface-mount outline with exposed thermal pad. The package supports high-power dissipation when mounted on ≥0.5in² 1oz copper area (θjA = 60°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3856ES-2.5/NOPB, LP3856ES-2.5 offers identical performance with different RoHS status, while TPS75725KTTT trades away remote sensing for lower dropout and noise-making it viable only in local-regulation, space-constrained designs.

Availability

LP3856ES-2.5/NOPB is available at Aetrix Electronics and suitable for microprocessor core power, GTL bus termination, SCSI termination, and battery-powered instrumentation requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for LP3856ES-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 designing analog ICs, embedded processors, and power management solutions for industrial, automotive, and communications markets.

The LP3856ES-2.5/NOPB belongs to TI's ultra-low-dropout linear regulator family, engineered for high-current, low-voltage applications demanding fast transient response, ceramic capacitor compatibility, and remote load regulation in compact packages.

FAQ

What is the minimum input voltage required for LP3856ES-2.5/NOPB to maintain regulation?

The minimum input voltage for LP3856ES-2.5/NOPB is determined by its dropout specification: VIN must be ≥ VOUT + dropout voltage. At 3A load, dropout is 390mV typical, so VIN ≥ 2.5V + 0.39V = 2.89V. The datasheet also specifies absolute minimum VIN as 2.5V, but actual functional minimum depends on load current and temperature. LP3856ES-2.5/NOPB will not regulate properly below this margin.

Can LP3856ES-2.5/NOPB operate stably with only ceramic capacitors?

Yes, LP3856ES-2.5/NOPB is explicitly characterized for stability with ceramic output capacitors, provided CIN and COUT values meet TI's load-current-dependent limits shown in Figure 29 of the datasheet. For 3A load, ceramic COUT must not exceed the value allowed by the corresponding ceramic CIN - typically requiring near 1:1 CIN:COUT ratio. LP3856ES-2.5/NOPB does not require ESR for stability, unlike older LDOs.

How does the SENSE pin improve regulation in LP3856ES-2.5/NOPB?

The SENSE pin on LP3856ES-2.5/NOPB allows feedback to be taken directly at the load instead of at the VOUT pin, eliminating voltage error caused by PCB trace resistance between the regulator and load. With 100mΩ trace resistance and 3A load, conventional regulation would drop 300mV at the load; using SENSE reduces that error to <50mV. LP3856ES-2.5/NOPB must have SENSE tied to VOUT if unused.

What is the purpose of the ERROR flag on LP3856ES-2.5/NOPB, and how is it used?

The ERROR flag on LP3856ES-2.5/NOPB is an open-drain output that pulls low when VOUT falls >10% below nominal (i.e., <2.25V for 2.5V output) due to input undervoltage, overload, or thermal limit. It includes built-in hysteresis (~5% of VOUT) to prevent chatter. LP3856ES-2.5/NOPB requires a 10kΩ pull-up resistor on ERROR; connect ERROR to GND if unused. The flag is invalid during shutdown.

Does LP3856ES-2.5/NOPB include thermal protection, and how does it behave under overload?

Yes, LP3856ES-2.5/NOPB includes thermal shutdown and foldback current limiting. Under sustained overload or short-circuit, the device cycles the PMOS pass element on/off to limit average power dissipation. As junction temperature rises, the duty cycle decreases until thermal shutdown fully disables output. Recovery is automatic once temperature falls below the hysteresis threshold. This protects LP3856ES-2.5/NOPB without requiring external circuitry.