STMicroelectronics LD2980CM25TR

Overview

LD2980CM25TR from STMicroelectronics is a 2.5 V fixed-output ultra-low-dropout linear voltage regulator in SOT23-5L package, delivering up to 50 mA with 120 mV typical dropout at 50 mA, 80 µA quiescent current in active mode, and <1 µA shutdown current. It features logic-controlled inhibit (TTL-compatible), internal thermal/current limiting, ±0.5% output tolerance (A version), and stable operation with low-ESR ceramic capacitors - used as local power supply for RF sections and sensor interfaces in portable electronics.

For engineers reviewing the LD2980CM25TR datasheet, LD2980CM25TR pinout, LD2980CM25TR application, or LD2980CM25TR equivalent, key selection criteria include dropout voltage at light/heavy load, inhibit logic thresholds (V_IL = 0.18 V, V_IH = 1.3 V), output noise (160 µV_RMS), thermal shutdown (170 °C), and compatibility with 1–2.2 µF ceramic output capacitors.

Technical Context

The LD2980CM25TR uses a PNP pass transistor architecture enabling ultra-low dropout (7 mV typ. at 1 mA; 120 mV typ. at 50 mA) and minimal quiescent current across load and temperature. Its feedback loop is optimized for stability with ceramic capacitors down to 1 µF (for ≥3.8 V versions) or 2.2 µF (for 2.85–3.3 V variants); the 2.5 V variant requires ≥2.2 µF per Figure 19.

Shutdown is implemented via an active-low INHIBIT pin (Pin 3) with no internal pull-up - requiring external biasing to VI or GND. The device exhibits reverse-current blocking (no body diode), limiting reverse current to ~160 µA when V_OUT > V_IN, and achieves 63 dB supply voltage rejection at 1 kHz with 10 µF output capacitance.

Key Specifications

Pinout & Package

SOT23-5L: 5-pin surface-mount package (2.95 × 1.60 mm footprint, 1.3 mm height), RoHS-compliant and ECOPACK® certified.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-quiescent-current LDO applications.

Compared with MCP1700T-2502E/TT and TNIV2525025R, the LD2980CM25TR uniquely balances ultra-low IQ, integrated shutdown, SOT23-5L compatibility, and ceramic-capacitor stability - making it optimal for compact, battery-critical systems requiring both precision and controllability.

Availability

LD2980CM25TR is available at Aetrix Electronics and suitable for wireless sensor nodes, wearable health monitors, IoT edge gateways, and smart home motion detectors requiring stable component supply across extended product lifecycles.

Supply support for LD2980CM25TR 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 chips for industrial, automotive, and consumer markets.

The LD2980 series belongs to ST's ultra-low-IQ LDO portfolio, engineered specifically for energy-harvesting and battery-powered applications demanding nanoscale standby current and ceramic-capacitor simplicity.

FAQ

What is the minimum output capacitance required for stability with LD2980CM25TR?

The LD2980CM25TR requires a minimum 2.2 µF X7R/X5R ceramic capacitor on the output for stable operation across -40 to 125 °C, as specified in Figure 19 of the datasheet. Using less than 2.2 µF risks oscillation unless a series resistor is added to emulate required ESR - but ST recommends adhering to the 2.2 µF minimum for robustness.

Can the INHIBIT pin be left floating?

No - the INHIBIT pin has no internal pull-up or pull-down and must never be left floating. If shutdown control is unused, tie Pin 3 directly to VIN to ensure continuous operation. Floating the pin may cause erratic enable/disable behavior due to noise coupling, potentially leading to unintended power cycling or increased quiescent current.

Does LD2980CM25TR support reverse voltage protection?

The LD2980CM25TR does not include reverse-input protection, but its PNP pass transistor inherently blocks reverse current flow from VOUT to VIN. When VOUT exceeds VIN, reverse current is limited to ~160 µA via internal feedback resistors - sufficient to prevent damage but not a substitute for explicit reverse-polarity protection in harsh environments.

How does thermal performance compare between SOT23-5L and DFN packages at 50 mA?

In SOT23-5L, R_thJA is 255 °C/W - resulting in ~1.3 °C rise at 50 mA (P_D ≈ 6.25 mW). In contrast, a typical DFN-6 package achieves R_thJA ≈ 160 °C/W, reducing junction rise to ~1.0 °C. While both remain well below thermal shutdown (170 °C), the DFN offers marginally better steady-state thermal headroom in high-density layouts.