Texas Instruments LP3873ESX-5.0/NOPB

Overview

LP3873ESX-5.0/NOPB from Texas Instruments is a 3A ultra-low-dropout linear regulator optimized for microprocessor and DSP power supplies, delivering 5.0V ±1.5% output with 800mV dropout at 3A load, 6mA ground current, and 1µA shutdown quiescent current. It operates from 2.5V–7.0V input and features an open-drain ERROR flag for output monitoring.

For engineers reviewing the LP3873ESX-5.0/NOPB datasheet, LP3873ESX-5.0/NOPB pinout, LP3873ESX-5.0/NOPB application, or LP3873ESX-5.0/NOPB equivalent, key selection criteria include dropout performance under full 3A load, remote-sense capability (not available on LP3873 variant), thermal protection behavior, and minimum output capacitor requirements for stability.

Technical Context

This CMOS-based LDO uses a PMOS pass element to achieve ultra-low dropout-80mV at 300mA and 800mV at 3A-enabling operation with minimal VIN–VOUT margin. Its error amplifier and reference circuitry are designed for fast transient response, critical in low-voltage digital loads where step-load changes exceed 1A/µs.

The device integrates overtemperature and overcurrent protection, with short-circuit limiting set at 6A peak and thermal shutdown activating above +125°C junction temperature. The ERROR flag provides hysteresis (5–8% of VOUT) and resets within 1µs after regulation recovery.

Key Specifications

Pinout & Package

LP3873ESX-5.0/NOPB is packaged in a 5-pin DDPAK/TO-263 surface-mount package with exposed thermal pad (KTT0005B). The package supports high-power dissipation via PCB copper area and is RoHS-compliant and lead-free (NOPB suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3873ESX-5.0/NOPB, TSS721AIPW offers smaller footprint but sacrifices 50% current capacity and fault monitoring; TPS75733KTTT delivers better efficiency at 3.3V but cannot replace LP3873ESX-5.0/NOPB without voltage translation or layout revision.

Availability

LP3873ESX-5.0/NOPB is available at Aetrix Electronics and suitable for microprocessor power supplies, GTL/SSTL bus terminators, and DSP power delivery requiring stable component supply, long-term lifecycle support, and traceable manufacturing origin.

Supply support for LP3873ESX-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 expertise in high-reliability linear regulators and power delivery ICs.

The LP3873 series belongs to TI's ultra-low-dropout LDO portfolio, engineered specifically for high-current, low-voltage digital systems where transient response, thermal robustness, and output accuracy are critical - including telecom infrastructure, test equipment, and industrial control.

FAQ

What is the maximum input voltage rating for LP3873ESX-5.0/NOPB?

The absolute maximum input voltage for LP3873ESX-5.0/NOPB is +7.5V, but the recommended operating range is 2.5V to 7.0V. Exceeding 7.0V may trigger internal protection circuits or reduce reliability. The minimum input is determined by dropout: for 5.0V output, VIN must be ≥5.8V at 3A load to maintain regulation. Always observe derating curves in the datasheet for elevated temperature operation.

Does LP3873ESX-5.0/NOPB support remote sensing?

No, LP3873ESX-5.0/NOPB does not support remote sensing. That function is exclusive to the LP3876 variant, which substitutes the ERROR pin with a SENSE pin. LP3873ESX-5.0/NOPB regulates voltage at the VOUT pin only; any PCB trace resistance between VOUT and the load introduces proportional IR drop. For remote-load applications, consider LP3876-5.0 or add external compensation circuitry.

What output capacitor is required for stable operation of LP3873ESX-5.0/NOPB?

LP3873ESX-5.0/NOPB requires a minimum 10µF output capacitor with ESR between 10mΩ and 1Ω, placed within 1 cm of the device using dedicated low-impedance traces. Ceramic (X7R/X5R) or solid tantalum capacitors are recommended; aluminum electrolytics are discouraged due to ESR drift at low temperatures. The capacitor must be rated for ≥6.3V and located directly between VOUT and GND pins.

How does the ERROR flag on LP3873ESX-5.0/NOPB behave during shutdown?

When the SD pin is pulled low, the ERROR flag on LP3873ESX-5.0/NOPB is forced invalid and its state becomes undefined - it does not assert or deassert reliably. This is intentional power-saving behavior. To monitor output status during normal operation only, tie SD to VIN via 10kΩ and use the ERROR pin with a compatible pull-up resistor (10kΩ–1MΩ). Do not rely on ERROR during active shutdown.

Is LP3873ESX-5.0/NOPB pin-compatible with other members of the LP3873/LP3876 family?

LP3873ESX-5.0/NOPB shares identical pinout and package (5-pin DDPAK/TO-263) with all LP3873 variants (e.g., LP3873ESX-3.3/NOPB), but is not pin-compatible with LP3876 devices - the LP3876 substitutes the ERROR pin with SENSE. Swapping LP3873ESX-5.0/NOPB for LP3876-5.0 requires PCB modification to reroute the fifth pin function and update external biasing.