STMicroelectronics LD2980CU50TR

Overview

LD2980CU50TR from STMicroelectronics is a 5.0 V fixed-output ultra-low-dropout linear voltage regulator in SOT23-5L package, delivering up to 50 mA with 120 mV typical dropout at full load, 160 µVRMS output noise, and logic-controlled shutdown via INHIBIT pin. It operates from 2.5 V to 16 V input, supports low-ESR ceramic capacitors, and targets precision low-power supply rails in portable electronics.

For engineers reviewing the LD2980CU50TR datasheet, LD2980CU50TR pinout, LD2980CU50TR application, or LD2980CU50TR equivalent, key selection criteria include dropout voltage at 50 mA, quiescent current in ON/OFF modes, ±0.5% output tolerance (C version), thermal shutdown threshold, and compatibility with 1 µF ceramic output capacitors.

Technical Context

The LD2980CU50TR uses a PNP pass transistor architecture enabling ultra-low dropout-7 mV typ. at 1 mA and 120–150 mV typ. at 50 mA-while maintaining stability with 1 µF low-ESR ceramic output capacitors. Its inhibit control pin (Pin 3) accepts TTL-compatible logic levels (VIH ≥ 1.3 V, VIL ≤ 0.18 V) and draws <1 µA in OFF mode.

Internal protection includes current limiting, thermal shutdown at 170 °C, and reverse-current blocking (no body diode). Output voltage accuracy is ±0.5% over –40 to 125 °C, and supply voltage rejection is 63 dB at 1 kHz with 10 µF output capacitor.

Key Specifications

Pinout & Package

SOT23-5L is a 5-pin surface-mount plastic package (2.95 × 1.60 mm footprint, 1.30 mm max height) with exposed pad for thermal enhancement. Pin 4 is NC (not connected); all other pins are electrically active and require proper PCB layout per ST's recommended footprint (Figure 24).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TC1015-5.0VCT713 and MCP1702T-5002E/MB, the LD2980CU50TR uniquely combines ultra-low dropout (120 mV), sub-µA shutdown, reverse-current blocking, and 160 µVRMS noise - making it optimal for compact, battery-sensitive, and fault-resilient designs.

Availability

LD2980CU50TR is available at Aetrix Electronics and suitable for portable audio systems, BLE sensor nodes, industrial I/O modules, and automotive cabin cameras requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LD2980CU50TR 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 LD2980 series belongs to ST's ultra-low-IQ LDO portfolio, engineered specifically for energy-constrained portable and always-on embedded systems where dropout voltage, noise, and shutdown leakage directly impact battery runtime and signal fidelity.

FAQ

What is the minimum output capacitance required for stability with LD2980CU50TR?

For the 5.0 V version, ST specifies a minimum 2.2 µF X7R/X5R ceramic capacitor with ESR between 10 mΩ and 300 mΩ (per Figure 18). Using a 1 µF capacitor requires adding a series resistor to emulate stable ESR; layout must place the capacitor within 12.7 mm of VOUT and GND pins.

Can LD2980CU50TR be used with an input voltage lower than 5.0 V?

No - the absolute minimum operating input voltage is 2.5 V, but regulation requires VIN ≥ VOUT + VDROP. At 50 mA load, VDROP is 120–150 mV, so VIN must be ≥ 5.12 V to maintain 5.0 V output. Below that, output collapses linearly with input.

Is the INHIBIT pin internally pulled up or pulled down?

Neither - the INHIBIT pin has no internal pull-up or pull-down. It must never be left floating. To enable output, connect it to VIN (≥1.3 V); to disable, drive it to GND or ≤0.18 V. A weak external pull-up to VIN is acceptable if system logic cannot actively drive low.

Does LD2980CU50TR support reverse current protection when VOUT > VIN?

Yes - the internal PNP pass transistor lacks a parasitic body diode, preventing reverse current flow from VOUT to VIN. When VOUT is forced above VIN, only ~160 µA flows through internal feedback resistors to GND (per Figure 22), eliminating need for external blocking diodes.