Texas Instruments LP3981ILD-2.83/NOPB

Overview

LP3981ILD-2.83/NOPB from Texas Instruments is a micropower, ultra-low-dropout CMOS voltage regulator delivering 300 mA at fixed 2.83 V output with 132 mV typical dropout at full load, ≤1 µA shutdown current, and 35 µV_RMS output noise (10 Hz–100 kHz). It operates from 2.5 V to 6 V input and targets power-sensitive RF sections in cellular handsets.

For engineers reviewing the LP3981ILD-2.83/NOPB datasheet, LP3981ILD-2.83/NOPB pinout, LP3981ILD-2.83/NOPB application, or LP3981ILD-2.83/NOPB equivalent, key selection criteria include dropout performance under 300-mA load, ceramic-capacitor stability (2.2 µF min), EN logic thresholds (VIH = 1.4 V, VIL = 0.4 V), thermal resistance in WSON-6 (R_θJA = 56.5 °C/W), and BYPASS-pin noise reduction capability.

Technical Context

The LP3981ILD-2.83/NOPB uses a CMOS pass element with internal bandgap reference (1.23 V) and fast-turnon circuitry enabling 240 µs typical startup time. Its feedback loop incorporates OUT-SENSE for accurate remote sensing and maintains regulation down to VIN = VOUT + 0.3 V.

It integrates thermal shutdown (160 °C trip, 20 °C hysteresis) and short-circuit current limiting (600 mA steady-state), while PSRR exceeds 55 dB at 10 kHz and holds >60 dB at 1 kHz across temperature and load conditions.

Key Specifications

Pinout & Package

LP3981ILD-2.83/NOPB is housed in a 6-pin WSON package (4.00 mm × 3.00 mm) with exposed thermal pad connected to GND. The package supports high-power-density layouts and requires solder paste stencil optimization for thermal pad reflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLS850F2TLE and TPS7A0528PDQNR, LP3981ILD-2.83/NOPB uniquely balances 300 mA delivery, 35 µV_RMS noise, remote sensing, and sub-1 µA shutdown in a thermally efficient WSON-6 package-making it optimal for consumer wireless RF power domains where noise, size, and battery life are co-constrained.

Availability

LP3981ILD-2.83/NOPB is available at Aetrix Electronics and suitable for CDMA/WCDMA handset design, portable information appliance power management, and low-noise RF subsystems requiring stable component supply and long-term manufacturability.

Supply support for LP3981ILD-2.83/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 ICs for portable and industrial systems.

The LP3981 family was designed specifically for battery-powered wireless applications demanding ultra-low noise, micropower shutdown, and ceramic-capacitor compatibility-enabling compact, high-efficiency power rails in cellular handsets and portable electronics.

FAQ

What is the minimum input voltage required for LP3981ILD-2.83/NOPB to regulate at full 300 mA load?

The LP3981ILD-2.83/NOPB requires VIN ≥ VOUT + 0.3 V = 3.13 V to maintain regulation at 300 mA. Below this, dropout behavior occurs-output voltage drops linearly with input. At 300 mA, typical dropout is 132 mV, so 3.0 V input yields ~2.87 V output, still within ±3% tolerance. Full specification applies only above 3.13 V.

Can LP3981ILD-2.83/NOPB operate without the BYPASS capacitor?

Yes, LP3981ILD-2.83/NOPB functions without the BYPASS capacitor but with higher output noise: 35 µV_RMS requires the 0.033 µF cap on the BYPASS pin. Without it, noise rises significantly-typically >100 µV_RMS. The BYPASS pin is high-impedance; no DC loading is permitted, and leakage must remain below 1 nA to preserve output accuracy.

Is the OUT-SENSE pin mandatory for LP3981ILD-2.83/NOPB operation?

Yes, the OUT-SENSE pin is mandatory and must be shorted directly to the OUT pin. It provides feedback to the error amplifier for precise regulation. Leaving it unconnected or routing it separately causes output voltage inaccuracy and potential instability. The pin is not optional-it is integral to the device's closed-loop control architecture.

What thermal derating applies to LP3981ILD-2.83/NOPB in its WSON-6 package at 60°C ambient?

With R_θJA = 56.5 °C/W, maximum junction temperature of 125°C, and 60°C ambient, allowable power dissipation is (125 − 60) / 56.5 ≈ 1.15 W. At 2.83 V output and 300 mA load, power dissipation is (VIN − 2.83) × 0.3. For VIN = 4.5 V, dissipation = 0.501 W-well within limit. Derating begins above ~1.15 W, not current.

Does LP3981ILD-2.83/NOPB support ceramic output capacitors smaller than 2.2 µF?

No-TI specifies 2.2 µF minimum for stability. Using <2.2 µF ceramic capacitors risks oscillation or poor transient response. The device is characterized and guaranteed only with 2.2–22 µF output capacitance and 5–500 mΩ ESR. Lower values may appear functional in bench tests but violate design validation requirements and are not production-qualified.