STMicroelectronics LD2982AM15R

Overview

LD2982AM15R from STMicroelectronics is a 50 mA fixed-output low-dropout (LDO) linear voltage regulator with logic-controlled inhibit function, delivering 1.5 V output at ±1% tolerance (25 °C), 120 mV dropout at 50 mA load, and 30 µV_RMS output noise with 10 nF bypass capacitor. It operates across –40 °C to 125 °C and supports battery-powered portable electronics requiring ultra-low quiescent current and high PSRR.

For engineers reviewing the LD2982AM15R datasheet, LD2982AM15R pinout, LD2982AM15R application, or LD2982AM15R equivalent, key selection criteria include its 1.5 V fixed output, SOT23-5L package compatibility, sub-1 µA shutdown current, 45 dB supply voltage rejection at 1 kHz, and low-ESR ceramic capacitor stability requirements.

Technical Context

The LD2982AM15R integrates a PMOS pass transistor enabling ultra-low dropout (as low as 1 mV at 1 mA), with internal current and thermal limiting for robust operation. Its inhibit input (pin 3) accepts TTL-compatible logic levels (V_IL ≤ 0.15 V, V_IH ≥ 2 V) to disable regulation and reduce quiescent current to <1 µA.

Stability is ensured with only 1 µF ceramic output capacitance (for V_O ≥ 3.8 V) or 2.2 µF (for 1.8–3.3 V), while the dedicated bypass pin (pin 4) accepts a 10 nF capacitor to reduce output noise to 30 µV_RMS (300 Hz–50 kHz). Input voltage range spans 2.5 V to 16 V.

Key Specifications

Pinout & Package

LD2982AM15R is housed in a compact SOT23-5L surface-mount package (2.8 × 1.6 × 1.3 mm), optimized for space-constrained portable designs and compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6219B152MR-G and AP2204K-15W5, the LD2982AM15R uniquely combines ±1% output accuracy, sub-1 µA inhibit-mode current, and 30 µV_RMS noise in SOT23-5L-making it optimal for high-precision, battery-sensitive portable instrumentation.

Availability

LD2982AM15R is available at Aetrix Electronics and suitable for wearable health monitors, industrial edge sensors, portable medical diagnostics, and automotive infotainment peripherals requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LD2982AM15R 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 silicon solutions for smart driving, power management, sensing, connectivity, and microcontrollers.

The LD2982 series belongs to ST's high-performance analog LDO portfolio, engineered specifically for ultra-low-noise, ultra-low-power portable and industrial applications where battery life, signal integrity, and thermal resilience are critical.

FAQ

What is the minimum input voltage required for stable 1.5 V output at 50 mA?

The LD2982AM15R requires an input voltage ≥1.62 V to maintain regulation at 50 mA load, based on its 120 mV typical dropout voltage. At lighter loads (e.g., 1 mA), input can drop to 1.501 V due to 1 mV dropout. Operation below these thresholds causes output collapse and should be avoided per absolute maximum ratings.

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

No-the INHIBIT pin must not be left floating. When unused, it must be tied directly to the IN pin to ensure continuous regulation. Floating the pin risks undefined logic states, potentially causing erratic enable/disable behavior and output instability due to leakage paths and noise susceptibility.

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

Yes-a 10 nF ceramic capacitor between the BYPASS pin and GND is required to achieve the specified 30 µV_RMS noise performance (300 Hz–50 kHz). Without it, output noise rises significantly (typ. >100 µV_RMS). The capacitor must be placed adjacent to the BYPASS pin with short, low-inductance traces to GND.

Does LD2982AM15R support reverse current protection?

Yes-the internal PMOS pass transistor lacks a body diode, preventing reverse current flow from OUT to IN when output voltage exceeds input. Reverse current under forced-V_REV conditions flows only through internal feedback resistors (typ. 160 µA), eliminating need for external blocking diodes in back-powered scenarios.