Texas Instruments LP3984IMF-1.5/NOPB

Overview

LP3984IMF-1.5/NOPB from Texas Instruments is a micropower, ultra-low-dropout CMOS voltage regulator delivering 1.5 V at up to 150 mA from 2.5–6.0 V input, featuring 75 mV typical dropout at full load, ≤1.2 µA shutdown current, and stable operation with 1 µF tantalum output capacitor. It serves as a primary power rail regulator in space-constrained battery-powered RF front-ends and baseband ICs.

For engineers reviewing the LP3984IMF-1.5/NOPB datasheet, LP3984IMF-1.5/NOPB pinout, LP3984IMF-1.5/NOPB application, or LP3984IMF-1.5/NOPB equivalent, key selection criteria include its 1.5 V fixed output, SOT-23-5 package compatibility, logic-controlled enable interface, thermal shutdown protection, and PSRR performance of 60 dB at 1 kHz for noise-sensitive analog/RF subsystems.

Technical Context

The LP3984IMF-1.5/NOPB employs a CMOS pass transistor architecture optimized for minimal quiescent current and ultra-low dropout across its −40°C to +125°C operating junction temperature range. Its internal bandgap reference and error amplifier maintain ±1.2% output voltage tolerance over line, load, and temperature.

It integrates logic-compatible enable control (VIH = 1.4 V, VIL = 0.4 V), fast 20 µs turn-on time, short-circuit current limiting (600 mA), and thermal shutdown with 20°C hysteresis - all while requiring only 1 µF tantalum output capacitance with 2–10 Ω ESR for stability.

Key Specifications

Pinout & Package

SOT-23-5 package (DBV drawing), 2.9 mm × 1.6 mm × 1.15 mm body, lead-free (RoHS & no Sb/Br), moisture sensitivity level 1, reflow peak temp 260°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSS721AIDR and TPS78015QDRVRQ1, the LP3984IMF-1.5/NOPB uniquely balances micropower shutdown (≤1.2 µA), ultra-low dropout (75 mV), and guaranteed tantalum-cap stability - making it optimal for compact, battery-driven RF subsystems where size, efficiency, and component count are constrained.

Availability

LP3984IMF-1.5/NOPB is available at Aetrix Electronics and suitable for CDMA/WCDMA handset power management, portable information appliance keep-alive rails, and low-noise RF biasing requiring stable component supply across production lifecycles.

Supply support for LP3984IMF-1.5/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 specializing in analog, embedded processing, and connectivity technologies, with leadership in power management innovation since 1930.

The LP3984IMF-1.5/NOPB belongs to TI's micropower LDO family engineered specifically for space- and power-constrained portable wireless devices, emphasizing ultra-low IQ, fast transient response, and capacitor flexibility in subminiature packages.

FAQ

What is the maximum input voltage rating for the LP3984IMF-1.5/NOPB?

The LP3984IMF-1.5/NOPB has an absolute maximum input voltage rating of 6.5 V, but its recommended operating input voltage range is 2.5 V to 6.0 V. Operation above 6.0 V risks exceeding safe junction temperature limits and may trigger thermal shutdown or cause permanent damage. Always ensure VIN remains within the specified operating range during normal use and transient conditions.

Can the LP3984IMF-1.5/NOPB operate stably with ceramic output capacitors?

The LP3984IMF-1.5/NOPB is explicitly characterized and guaranteed stable with 1–22 µF tantalum capacitors having 2–10 Ω ESR. While some ceramic capacitors may function in specific layouts, TI does not guarantee stability with ceramics due to their near-zero ESR, which can induce oscillation. For ceramic-based designs, TI recommends the TPS7A05 or TPS7A16 families instead of the LP3984IMF-1.5/NOPB.

Does the LP3984IMF-1.5/NOPB require an input capacitor, and what type is recommended?

Yes, the LP3984IMF-1.5/NOPB requires a minimum 1 µF input capacitor between VIN and GND, placed within 1 cm of the device. TI recommends ceramic, tantalum, or film capacitors - with no ESR requirement - but cautions that tantalum types must be rated for surge current if connected directly to batteries. The capacitor improves line transient response and reduces input ripple coupling into the regulated output.

What is the thermal shutdown behavior of the LP3984IMF-1.5/NOPB?

The LP3984IMF-1.5/NOPB activates thermal shutdown at 160°C junction temperature and remains latched off until junction temperature falls by 20°C (to ~140°C), at which point it automatically recovers. This hysteresis prevents cycling during marginal thermal conditions. During shutdown, quiescent current remains ≤1.2 µA, and VOUT collapses to near-GND. Recovery is seamless with no external reset required.

Is the LP3984IMF-1.5/NOPB pin-compatible with other output voltage variants in the LP3984 family?

Yes, all LP3984 variants - including LP3984IMF-1.5/NOPB, LP3984IMF-1.8/NOPB, and LP3984IMF-3.1/NOPB - share identical SOT-23-5 (DBV) pinout and footprint. They are drop-in replacements for one another in the same PCB layout, differing only in factory-trimmed output voltage. No redesign or layout change is needed when swapping between these fixed-output versions.