Texas Instruments LP3982ILD-3.0/NOPB

Overview

LP3982ILD-3.0/NOPB from Texas Instruments (formerly National Semiconductor) is a micropower, ultra low-dropout, low-noise 300mA CMOS linear regulator in an 8-pin LLP package, delivering 3.0V fixed output with ±2% tolerance, 120mV typical dropout at 300mA, and 90µA typical quiescent current - designed for battery-powered wireless handsets and portable information appliances.

For engineers reviewing the LP3982ILD-3.0/NOPB datasheet, LP3982ILD-3.0/NOPB pinout, LP3982ILD-3.0/NOPB application, or LP3982ILD-3.0/NOPB equivalent, key selection criteria include its 1nA shutdown current, 37µV RMS output noise (10Hz–100kHz), stability with 2.2µF ceramic output capacitors, and FAULT pin for regulation fault detection.

Technical Context

The LP3982ILD-3.0/NOPB employs a PMOS pass transistor architecture enabling ultra-low dropout and near-zero drive current consumption versus PNP-based LDOs. Its internal bandgap reference, error amplifier, and fault-detection comparator support precise regulation and real-time monitoring of overcurrent, thermal overload, and input-to-output differential conditions.

It features an internally generated compensation zero to ensure stability with low-ESR ceramic capacitors as small as 2.2µF, and integrates a dedicated noise-bypass capacitor terminal (CC pin) that reduces output voltage noise to 37µV RMS without degrading transient response - critical for DSP core power and RF-sensitive applications.

Key Specifications

Pinout & Package

LP3982ILD-3.0/NOPB is housed in an 8-pin LLP (Leadless Leadframe Package), 3mm × 3mm × 0.8mm body, thermally enhanced with exposed thermal pad - optimized for high-density portable PCBs requiring minimal footprint and efficient heat dissipation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP3982ILD-3.0/NOPB, TPS73030DBVR offers smaller footprint but sacrifices dropout performance and fault diagnostics; MCP1700T-3002E/MB achieves ultra-low shutdown current but lacks output current headroom and noise-reduction capability - making LP3982ILD-3.0/NOPB the balanced choice for noise-sensitive, battery-critical 300mA applications requiring robust protection signaling.

Availability

LP3982ILD-3.0/NOPB is available at Aetrix Electronics and suitable for wireless handsets, DSP core power, and portable information appliances requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LP3982ILD-3.0/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 acquired National Semiconductor in 2011 and maintains its precision analog and power management portfolio, emphasizing high-reliability, low-power, and automotive-qualified components.

The LP3982ILD-3.0/NOPB belongs to TI's legacy micropower LDO family, engineered specifically for battery-constrained portable electronics demanding ultra-low dropout, low noise, and intelligent fault reporting - not general-purpose power conversion.

FAQ

What is the maximum input voltage rating for LP3982ILD-3.0/NOPB?

The absolute maximum input voltage for LP3982ILD-3.0/NOPB is 6.5V, but the recommended operating range is 2.5V to 6.0V per the datasheet. Exceeding 6.0V risks violating safe operating area limits, especially under high ambient temperature or heavy load conditions. The device's internal protection circuitry does not guarantee survival beyond 6.5V, and sustained operation above 6.0V may accelerate parametric drift or reduce lifetime reliability. Always maintain VIN ≤ 6.0V in production designs using LP3982ILD-3.0/NOPB.

Does LP3982ILD-3.0/NOPB require an external noise-bypass capacitor?

Yes, LP3982ILD-3.0/NOPB requires a 33nF NPO or COG ceramic capacitor connected between the CC pin (Pin 7) and ground to achieve its specified 37µV RMS output noise. Omitting this capacitor increases broadband noise by up to 3× and degrades PSRR above 10kHz. The CC pin connects directly to the bandgap reference node, so capacitor leakage must remain below 1nA - making NPO/COG types mandatory. Film or electrolytic capacitors are unsuitable due to excessive leakage and ESL.

Can LP3982ILD-3.0/NOPB operate stably with no output load?

Yes, LP3982ILD-3.0/NOPB is explicitly characterized for no-load stability and remains regulated with zero output current - a requirement verified in National Semiconductor's datasheet Section 7 ("No-Load Stability"). This behavior is enabled by its PMOS topology and internal compensation, making it suitable for CMOS RAM keep-alive circuits and standby power rails. Unlike many LDOs, it does not require minimum load resistors or dummy loads to maintain regulation or avoid oscillation when idle.

What is the thermal performance of LP3982ILD-3.0/NOPB in its LLP package?

LP3982ILD-3.0/NOPB in the 8-pin LLP package has a typical junction-to-ambient thermal resistance (θJA) of ~120°C/W when mounted on a 2-layer PCB with a 1-in² copper pour connected to the exposed thermal pad (EPAD). This value assumes standard 1oz copper, no forced airflow, and proper solder coverage of the EPAD. Without thermal pad connection, θJA degrades to >200°C/W, risking thermal shutdown at >150mW dissipation. For continuous 300mA operation at 3.0V output with 4.5V input, power dissipation is 450mW - requiring adequate copper area or airflow to maintain TJ < 125°C.

How does the FAULT pin on LP3982ILD-3.0/NOPB function during dropout?

The FAULT pin on LP3982ILD-3.0/NOPB asserts low when the input-to-output voltage differential falls below a threshold tracking the dropout voltage - typically ~180mV at 300mA - providing early warning before regulation is lost. It also activates during thermal shutdown or current-limit events. As an open-drain output, it requires an external pull-up resistor (100kΩ recommended); the pin sinks up to 2mA when active. This enables host microcontrollers to initiate controlled shutdown or battery-saving modes before system brownout occurs - a feature not present in basic LDOs like the LP2985.