Texas Instruments LP3856ES-5.0/NOPB

Overview

LP3856ES-5.0/NOPB from Texas Instruments is a 5.0V, 3A ultra-low-dropout linear regulator in TO-263-5 package, featuring 390mV dropout at full load, ±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 delivers stable microprocessor core power with fast transient response.

For engineers reviewing the LP3856ES-5.0/NOPB datasheet, LP3856ES-5.0/NOPB pinout, LP3856ES-5.0/NOPB application, or LP3856ES-5.0/NOPB equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, and two confirmed alternative parts for system-level power supply design.

Technical Context

The LP3856ES-5.0/NOPB uses a PMOS pass element on a CMOS process enabling ultra-low quiescent current (4mA typical at 3A) independent of load, and supports ceramic or tantalum output capacitors ≥10µF with ESR-stable operation. Its SENSE pin enables Kelvin sensing for remote load regulation, distinguishing it from the LP3853 variant which lacks this feature.

It integrates overtemperature and overcurrent protection, delivers 10nA shutdown current, and features an open-drain ERROR flag that asserts low when VOUT drops >10% below nominal-critical for fault monitoring in DSP and microprocessor supplies. The device maintains 0.08% load regulation and 73dB PSRR at 120Hz with 10µF ceramic output capacitance.

Key Specifications

Pinout & Package

LP3856ES-5.0/NOPB is packaged in TO-263-5 (D²Pak), surface-mount, thermally enhanced plastic package with exposed thermal pad. Pin 1–5 are bent/staggered for manual soldering and automated assembly compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3856ES-5.0/NOPB, TPS7A4700RGWR trades 3A current and SENSE capability for lower noise and wider VIN range, while LP3878SD-5.0/NOPB sacrifices 390mV dropout and remote sensing for lower unit cost-making LP3856ES-5.0/NOPB optimal for high-current, precision point-of-load regulation.

Availability

LP3856ES-5.0/NOPB is available at Aetrix Electronics and suitable for microprocessor core supplies, GTL+ bus termination, SCSI-2/3 termination, and battery-powered instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LP3856ES-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 and embedded processing technologies, with decades of expertise in power management IC design and manufacturing.

The LP3856ES-5.0/NOPB belongs to TI's ultra-low-dropout linear regulator product line, engineered specifically for high-current, low-noise, and remote-sense applications in microprocessor, DSP, and industrial control systems.

FAQ

What is the minimum input voltage required for LP3856ES-5.0/NOPB to regulate 5.0V output?

The minimum input voltage is determined by dropout: LP3856ES-5.0/NOPB requires VIN ≥ VOUT + VDROPOUT. At 3A load, VDROPOUT = 390mV, so minimum VIN = 5.39V. At lighter loads (e.g., 300mA), dropout drops to 39mV, allowing VIN as low as 5.039V. The absolute minimum operating VIN is 2.5V-but that only applies if VOUT ≤ 2.5V − VDROPOUT, which does not hold for LP3856ES-5.0/NOPB's 5.0V output.

Can LP3856ES-5.0/NOPB operate with only ceramic capacitors, and what are the stability requirements?

Yes, LP3856ES-5.0/NOPB is stable with ceramic output capacitors ≥10µF, provided input capacitance is appropriately sized. For 3A load, stable operation requires ceramic input capacitance ≥ output capacitance (e.g., 47µF CIN + 47µF COUT). X7R or X5R dielectrics are mandatory-Z5U/Y5V types are unstable due to severe voltage/temperature capacitance loss. ESR must remain <10mΩ across operating conditions.

How does the SENSE pin on LP3856ES-5.0/NOPB improve regulation accuracy in real PCB layouts?

The SENSE pin on LP3856ES-5.0/NOPB enables Kelvin sensing: it monitors voltage directly at the load, not at the VOUT pin. This eliminates IR drop error across PCB traces. For example, with 100mΩ trace resistance and 3A load, conventional regulation would deliver only 4.7V at the load-while LP3856ES-5.0/NOPB with SENSE tied to the load maintains 5.0V ±1.5% at the point-of-load, improving regulation by >300mV.

What happens to the ERROR flag during shutdown mode of LP3856ES-5.0/NOPB?

When the SD pin is pulled low to activate shutdown mode, the ERROR flag on LP3856ES-5.0/NOPB is forced invalid-its state becomes undefined and should not be monitored. This is intentional power-saving behavior. The ERROR pin resumes valid operation only after SD returns high and the regulator completes its 25µs turn-on delay. During shutdown, the ERROR pin leakage remains <1nA, minimizing system-level current draw.

Is LP3856ES-5.0/NOPB pin-compatible with LP3853ES-5.0/NOPB, and what are the functional consequences of substitution?

No, LP3856ES-5.0/NOPB is not pin-compatible with LP3853ES-5.0/NOPB. In TO-263-5 package, LP3853 has ERROR pin on Pin 5, while LP3856 has SENSE on Pin 5. Substituting one for the other without PCB revision will cause either loss of fault reporting (if LP3856 replaces LP3853) or loss of remote sensing (if LP3853 replaces LP3856). Both share identical Pin 1–4 (SD/VIN/GND/VOUT), but Pin 5 function differs fundamentally.