STMicroelectronics LD2980ABM25TR

Overview

LD2980ABM25TR from STMicroelectronics is a 3.0 V fixed-output, ultra-low-dropout linear voltage regulator in SOT23-5L package, delivering up to 50 mA with 7 mV typical dropout at 1 mA load, 80 µA typical quiescent current in active mode, and <1 µA shutdown current-designed for battery-powered portable electronics requiring stable low-noise supply.

For engineers reviewing the LD2980ABM25TR datasheet, LD2980ABM25TR pinout, LD2980ABM25TR application, or LD2980ABM25TR equivalent, key selection criteria include guaranteed 3.0 V ±0.5% output tolerance over –40 to 125 °C, logic-controlled inhibit function (TTL-compatible), stability with low-ESR ceramic capacitors, and fast transient response in space-constrained designs.

Technical Context

The LD2980ABM25TR employs a PNP pass transistor architecture enabling ultra-low dropout voltage and minimal quiescent current across temperature. Its internal feedback loop is optimized for stability with 2.2 µF ceramic output capacitors and supports dynamic load steps from 1 mA to 50 mA with sub-100 µs recovery.

It integrates thermal shutdown (170 °C) and current limiting, while the INHIBIT pin (Pin 3) provides TTL-compatible enable/disable control with defined logic thresholds (V_INH ≤ 0.18 V for OFF, V_INL ≥ 1.3 V for ON), and no internal pull-up-requiring explicit biasing to avoid floating states.

Key Specifications

Pinout & Package

SOT23-5L is a 5-pin, surface-mount plastic package measuring 2.95 mm × 1.60 mm × 1.45 mm (max height), optimized for high-density PCB layouts and automated assembly. It features exposed pad for thermal enhancement and RoHS-compliant ECOPACK2 construction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout, low-quiescent-current regulator applications.

Compared with TPS78030DRVR and MCP1700T-3002E/TT, the LD2980ABM25TR uniquely balances ultra-low dropout (7 mV), low-noise (160 µV_RMS), and integrated inhibit control-making it optimal for active-duty portable systems where both efficiency and signal integrity matter.

Availability

LD2980ABM25TR is available at Aetrix Electronics and suitable for wearable sensor nodes, Bluetooth LE modules, industrial IoT edge nodes, and medical patch monitors requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for LD2980ABM25TR 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, sensors, and analog components for industrial, automotive, and consumer markets.

The LD2980 series belongs to ST's ultra-low-dropout linear regulator product line, engineered specifically for battery-powered portable electronics demanding minimal quiescent current, low noise, and logic-controlled power gating.

FAQ

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

The LD2980ABM25TR requires a minimum input voltage of 3.12 V at 50 mA load, based on its 120–150 mV typical dropout voltage specification. At room temperature and 50 mA, the datasheet specifies 120 mV typ., so 3.0 V + 0.12 V = 3.12 V ensures regulation. Derating for worst-case temperature (–40 to 125 °C) increases dropout to 225 mV, requiring ≥3.225 V input for guaranteed operation.

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

No-the INHIBIT pin (Pin 3) has no internal pull-up and must never be left floating. If shutdown is unused, it must be tied directly to VIN to maintain the regulator in permanent ON state. Leaving it unconnected risks undefined output behavior, intermittent shutdown, or increased leakage due to noise coupling.

Is an external resistor required in series with the output capacitor for stability?

No-stability is achieved with a 2.2 µF X7R ceramic capacitor (low-ESR, ≤100 mΩ) placed within 0.5″ of VOUT and GND pins. The datasheet explicitly states this value satisfies stability for 3.0 V and 3.3 V versions; adding a series resistor is only necessary if using capacitors below the recommended value or outside the ESR range shown in Figures 18–19.

Does the LD2980ABM25TR support reverse current protection?

Yes-the internal PNP pass transistor lacks a body diode, preventing reverse current flow from VOUT to VIN when output voltage exceeds input. However, a small reverse current (~160 µA) flows through internal feedback resistors to GND when VREV is applied; this is inherent to the resistor-divider topology and does not compromise system safety or regulation integrity.