STMicroelectronics LD2982AM30R

Overview

LD2982AM30R from STMicroelectronics is a 50 mA fixed-output low-dropout linear voltage regulator with 3.0 V output, logic-controlled inhibit function, ultra-low dropout (120 mV at 50 mA), 30 µV_RMS output noise, and ±1% output voltage tolerance at 25 °C. It operates across –40 °C to +125 °C and supports battery-powered portable electronics requiring stable, low-noise local regulation.

For engineers reviewing the LD2982AM30R datasheet, LD2982AM30R pinout, LD2982AM30R application, or LD2982AM30R equivalent, key selection criteria include its 1 µA shutdown current, 1 µF minimum ceramic output capacitor requirement, SOT23-5L package footprint, and bypass-capacitor–enabled noise reduction for sensitive analog rails.

Technical Context

The LD2982AM30R integrates a PNP pass transistor enabling ultra-low dropout operation-just 7 mV at 1 mA load-and features an independent INHIBIT pin (Pin 3) with TTL-compatible thresholds (V_IL ≤ 0.15 V, V_IH ≥ 2 V) for precise system-level power gating. Its internal feedback network uses implanted resistors (R1 = 42.6 kΩ, R2 = 51.15 kΩ) to set the 3.0 V output and enable reverse-current blocking.

Stability is ensured with a 1 µF ceramic output capacitor (low ESR required) and optional 10 nF bypass capacitor on Pin 4, reducing broadband noise to 30 µV_RMS (300 Hz–50 kHz). Supply voltage rejection remains ≥45 dB at 1 kHz, and thermal protection limits junction temperature to 125 °C under sustained overload.

Key Specifications

Pinout & Package

SOT23-5L package: 2.80 × 1.50 mm body, 0.95 mm pitch, 1.45 mm height, thermally enhanced exposed pad not present. RoHS-compliant, ECOPACK®-qualified.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, low-I_Q LDO applications.

Compared with XC6206P302MR and AP2210K-3.0TRG1, the LD2982AM30R uniquely combines sub-µA shutdown, bypass-enabled 30 µV_RMS noise, and 120 mV dropout in SOT23-5L-making it optimal for space-constrained, battery-critical, noise-sensitive designs requiring precise power sequencing.

Availability

LD2982AM30R is available at Aetrix Electronics and suitable for portable medical sensors, industrial IoT edge nodes, automotive cabin controllers, and audio DAC reference supplies requiring stable component supply across long-lifecycle deployments.

Supply support for LD2982AM30R 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, analog chips, and MEMS sensors for industrial, automotive, and consumer markets.

The LD2982 series belongs to ST's high-performance linear regulator product line, engineered specifically for ultra-low-noise, ultra-low-quiescent-current applications in battery-powered and signal-integrity–critical systems.

FAQ

What is the minimum input voltage required for regulation at 3.0 V output and 50 mA load?

The LD2982AM30R maintains regulation with input as low as 3.12 V at 50 mA load (120 mV dropout). Below this, output voltage drops linearly with input. Input must remain ≥2.5 V for basic functionality, but regulation is only guaranteed above V_OUT + V_DROP across temperature and load conditions.

Can the INHIBIT pin be left unconnected if shutdown functionality is not used?

No-the INHIBIT pin must not be left floating. When shutdown is unused, it must be tied directly to the IN pin to ensure reliable ON-state operation. Floating the pin risks erratic enable/disable behavior due to noise coupling or undefined logic level, potentially causing output instability or unintended power cycling.

Is a bypass capacitor mandatory for achieving 30 µV_RMS output noise?

Yes-30 µV_RMS noise is specified only when a 10 nF ceramic capacitor is connected between the Bypass pin and GND. Without it, typical output noise rises to ~120 µV_RMS. The capacitor must be placed adjacent to the device with short, low-inductance traces to preserve high-frequency noise suppression.

Does the LD2982AM30R support ceramic output capacitors with X5R or X7R dielectrics?

Yes-it is explicitly designed for ceramic output capacitors, including X5R and X7R types. ST recommends ≥1 µF for 3.0 V output (within 12.7 mm of OUT pin), with ESR <100 mΩ across –40 °C to +125 °C. X7R is preferred for wider temperature stability; X5R is acceptable if capacitance derating at temperature extremes is verified.