Texas Instruments LP3856ESX-5.0/NOPB

Overview

LP3856ESX-5.0/NOPB from Texas Instruments is a 3A ultra-low-dropout linear regulator with fixed 5.0V output, 390mV dropout at 3A, ±1.5% output voltage accuracy, and remote sense capability for improved load regulation in distributed power systems. It operates from 2.5V to 7.0V input and supports ceramic or tantalum output capacitors.

For engineers reviewing the LP3856ESX-5.0/NOPB datasheet, LP3856ESX-5.0/NOPB pinout, LP3856ESX-5.0/NOPB application, or LP3856ESX-5.0/NOPB equivalent, key selection considerations include dropout performance under full 3A load, SENSE pin implementation for remote load regulation, shutdown quiescent current (10nA), error flag hysteresis (5–8%), and stability with low-ESR ceramic capacitors.

Technical Context

The LP3856ESX-5.0/NOPB uses a PMOS pass element on a CMOS process enabling ultra-low dropout (390mV @ 3A) and load-independent quiescent current. Its internal error amplifier compares either VOUT (LP3853) or SENSE (LP3856) to a precision bandgap reference, delivering 0.08% load regulation and 0.02% line regulation.

It integrates overtemperature and overcurrent protection, an open-drain ERROR flag with 10% output undervoltage detection and built-in hysteresis, and a CMOS-compatible SD input with 1.3V threshold. The device is stable with ≥10µF output capacitance and supports ceramic capacitor configurations when input/output capacitance ratios are maintained per load current.

Key Specifications

Pinout & Package

LP3856ESX-5.0/NOPB is packaged in TO-263-5 (D²Pak), surface-mount, thermally enhanced package with exposed thermal pad. Pin 1 = SD (Shutdown), Pin 2 = VIN (Input), Pin 3 = GND (Ground), Pin 4 = VOUT (Output), Pin 5 = SENSE (Remote Sense).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR, LP3856ESX-5.0/NOPB delivers 3× output current and integrated SENSE but trades 13dB PSRR and 145µVrms higher noise. Against TPS75733KTTT, it offers tighter output accuracy (±1.5% vs ±2%), lower dropout (390mV vs 450mV), and remote sensing - critical for high-precision 5V distribution.

Availability

LP3856ESX-5.0/NOPB is available at Aetrix Electronics and suitable for microprocessor power supplies, GTL/SSTL bus terminators, and battery-powered instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LP3856ESX-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 company headquartered in Dallas, Texas, designing and manufacturing analog ICs, embedded processors, and high-reliability components for industrial, automotive, and communications markets.

The LP3856ESX-5.0/NOPB belongs to TI's ultra-low-dropout linear regulator product line, engineered specifically for high-current, low-voltage digital power delivery where precision, fast transient response, and remote load regulation are essential.

FAQ

What is the minimum input voltage required for LP3856ESX-5.0/NOPB to regulate 5.0V output?

The minimum input voltage is VOUT + VDROPOUT = 5.0V + 0.39V = 5.39V under full 3A load. At lighter loads, dropout decreases - e.g., 39mV at 300mA yields 5.039V minimum. Per datasheet, VIN must also meet the absolute minimum of 2.5V, but 5.39V governs for this 5.0V part. Always verify margin against worst-case dropout across temperature and tolerance.

Can LP3856ESX-5.0/NOPB operate stably with only ceramic capacitors?

Yes - LP3856ESX-5.0/NOPB is explicitly characterized for stability with ceramic output capacitors when input/output capacitance ratios follow TI's guidelines (e.g., ≥10µF ceramic CIN with ≤50µF ceramic COUT at 3A). X7R or X5R dielectrics are required to maintain capacitance across voltage and temperature; Z5U/Y5V types are unstable due to severe voltage coefficient.

How does the SENSE pin improve regulation in LP3856ESX-5.0/NOPB compared to standard LDOs?

The SENSE pin enables remote voltage sensing at the load, closing the feedback loop there instead of at VOUT. This compensates for IR drop in PCB traces - e.g., 100mΩ × 3A = 300mV loss - ensuring 5.0V ±1.5% is delivered *at the load*, not just at the regulator pin. LP3853 lacks this pin and regulates only at VOUT.

What is the purpose of the ERROR flag on LP3856ESX-5.0/NOPB, and how is it used?

The ERROR flag is an open-drain output that pulls low when VOUT falls >10% below 5.0V due to input undervoltage, overload, or thermal limit. It includes 5–8% hysteresis to prevent chatter. Use a 10kΩ pull-up to VIN; tie ERROR to GND if unused. During shutdown, ERROR is invalid - it only functions in active mode.

Does LP3856ESX-5.0/NOPB require a heat sink in TO-263-5 package at 3A continuous load?

Thermal performance depends on PCB layout. With 0.5in² 1oz copper area, θjA = 60°C/W. At 3A and 5.39V input (0.39V dropout), power dissipation is ~1.17W. Junction rise = 1.17W × 60°C/W = 70°C - acceptable at 25°C ambient (TJ = 95°C < 125°C max). For sustained 70°C+ ambient, add thermal vias or external heatsink.