Texas Instruments LP3982ILDX-1.8/NOPB

Overview

LP3982ILDX-1.8/NOPB from Texas Instruments (formerly National Semiconductor) is a micropower, ultra low-dropout, low-noise CMOS linear regulator delivering 300mA output at fixed 1.8V. It features 120mV typical dropout at full load, 90µA typical quiescent current, and 37µV_RMS output noise (10Hz–100kHz), enabling efficient power delivery in space-constrained, battery-powered systems such as wireless handsets and portable information appliances.

For engineers reviewing the LP3982ILDX-1.8/NOPB datasheet, LP3982ILDX-1.8/NOPB pinout, LP3982ILDX-1.8/NOPB application, or LP3982ILDX-1.8/NOPB equivalent, key selection criteria include its 1.8V fixed output, MSOP-8 package compatibility with MAX8860, shutdown current of 1nA typ, ±2% output tolerance, and stability with 2.2µF ceramic output capacitors.

Technical Context

The LP3982ILDX-1.8/NOPB employs a PMOS pass transistor architecture that eliminates external drive current requirements and enables ultra-low dropout operation. Its internal bandgap reference and error amplifier provide precise regulation, while integrated fault detection monitors input-to-output differential voltage to signal impending dropout, overcurrent, or thermal overload.

This regulator operates across 2.5V–6.0V input range and maintains stability without requiring minimum ESR output capacitors-unlike many LDOs-due to an internally generated compensation zero optimized for low-ESR ceramic capacitors as small as 2.2µF. The FAULT pin is open-drain and requires an external pull-up resistor.

Key Specifications

Pinout & Package

LP3982ILDX-1.8/NOPB is packaged in an 8-pin LLP (Leadless Leadframe Package), measuring 3.0mm × 3.0mm × 0.8mm, with wettable flank side walls for automated optical inspection. This thermally enhanced surface-mount package provides lower θ_JA than MSOP-8 when properly laid out with thermal vias and copper pour.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX8860EUB18+T and TLC7701QDCKR, LP3982ILDX-1.8/NOPB uniquely combines ultra-low dropout (120mV), sub-100µA quiescent current, integrated FAULT reporting, and guaranteed stability with 2.2µF ceramic output capacitors-making it optimal for next-generation portable electronics demanding both efficiency and diagnostic capability.

Availability

LP3982ILDX-1.8/NOPB is available at Aetrix Electronics and suitable for wireless handset baseband, DSP core power, and battery-powered medical sensors requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for LP3982ILDX-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 acquired National Semiconductor in 2011 and integrates its precision analog portfolio-including LDO regulators-into TI's broad power management ecosystem.

The LP3982ILDX-1.8/NOPB belongs to National Semiconductor's micropower LDO family, designed specifically for battery-powered portable electronics where ultra-low IQ, low noise, and minimal dropout are essential for maximizing runtime and signal fidelity.

FAQ

What is the maximum input voltage rating for LP3982ILDX-1.8/NOPB?

The absolute maximum input voltage for LP3982ILDX-1.8/NOPB is 6.5V, but the recommended operating range is 2.5V to 6.0V. Exceeding 6.5V risks permanent damage. For reliable operation, maintain VIN within spec-especially under transient conditions-and use appropriate input filtering. The LP3982ILDX-1.8/NOPB is commonly used with single-cell Li-ion (3.0–4.2V) and dual-cell alkaline (2.4–3.2V) sources.

Does LP3982ILDX-1.8/NOPB require an external bypass capacitor on the CC pin?

Yes, LP3982ILDX-1.8/NOPB achieves its specified 37µV_RMS output noise only when a 33nF NPO or COG ceramic capacitor is connected between the CC pin (Pin 6) and ground. Omitting this capacitor increases broadband noise significantly. The CC pin connects directly to the bandgap reference node, so capacitor leakage must be minimized-NPO/COG types are mandatory for best performance. LP3982ILDX-1.8/NOPB remains functional without CC, but noise performance degrades.

Is LP3982ILDX-1.8/NOPB pin-compatible with MAX8860?

Yes, LP3982ILDX-1.8/NOPB is pin-, package-, and specification-compatible with Maxim's MAX8860 in the 8-pin MSOP variant-but LP3982ILDX-1.8/NOPB uses the 8-pin LLP package. While electrical behavior matches closely (same 1.8V output, 300mA rating, 120mV dropout), LP3982ILDX-1.8/NOPB adds FAULT detection and lower quiescent current (90µA vs. 150µA). Layout reuse is feasible only if migrating from MSOP to LLP requires footprint adaptation.

What thermal protection features does LP3982ILDX-1.8/NOPB include?

LP3982ILDX-1.8/NOPB integrates thermal shutdown that activates at 160°C junction temperature, with 10°C hysteresis to prevent oscillation near the threshold. When triggered, the pass transistor turns off and FAULT pin asserts low. Recovery occurs only after junction temperature drops below ~150°C. This protects against sustained overload or poor PCB thermal design. The device's LLP package offers improved thermal resistance versus MSOP when paired with adequate copper area and thermal vias-critical for continuous 300mA operation.

Can LP3982ILDX-1.8/NOPB operate stably with zero load current?

Yes, LP3982ILDX-1.8/NOPB is explicitly designed for no-load stability, a requirement verified in its datasheet and application notes. It maintains regulation with I_OUT = 0mA-essential for applications like CMOS RAM keep-alive, real-time clock backup, or microcontroller sleep modes. Unlike many LDOs that require minimum load resistors, LP3982ILDX-1.8/NOPB needs no external load to remain stable, reducing system power overhead and simplifying design.