STMicroelectronics LD29080PT25R

Overview

LD29080PT25R from STMicroelectronics is a fixed-output 2.5 V, 800 mA low-dropout linear regulator in PPAK (Power Package) surface-mount package. It delivers ±1% output voltage accuracy over −40 °C to +125 °C, features 0.4 V typical dropout at 800 mA, and includes logic-controlled electronic shutdown, internal current/thermal limiting, and 100 µVRMS output noise (10 Hz–100 kHz). It is used in post-regulation of switching supplies for embedded computing and battery-powered instrumentation.

For engineers reviewing the LD29080PT25R datasheet, LD29080PT25R pinout, LD29080PT25R application, or LD29080PT25R equivalent, key selection criteria include guaranteed 800 mA output under 0.4 V dropout, shutdown control via INHIBIT pin, thermal performance (R_thJA = 100 °C/W), and compatibility with 10 µF ceramic output capacitance for stability.

Technical Context

The LD29080PT25R implements a high-accuracy bandgap reference and error amplifier driving a PNP pass transistor, enabling ultra-low dropout operation without requiring external compensation. Its INHIBIT pin (not internally pulled up) requires ≥2 V to enable regulation and sinks only 5–10 µA, supporting low-power system-level control.

Designed for medium-current loads where ground current and dropout voltage are critical, it operates across 3.5 V to 13 V input while maintaining 2.475–2.525 V output (±1%) over full temperature and load range. The device enters automatic shutdown above 14 V input and limits short-circuit current to 1.2 A.

Key Specifications

Pinout & Package

LD29080PT25R uses the PPAK (Power Package) thermally enhanced SMD package (6.0 × 6.2 mm body, 9.35–10.1 mm height), optimized for PCB heat spreading via exposed thermal pad (GND-connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV70725PDQNR and NCP1117ST2.5T3G, LD29080PT25R uniquely combines 800 mA capability, 0.4 V dropout, active-high INHIBIT control, and 100 µV_RMS noise - making it optimal for high-performance embedded systems where efficiency, precision, and controllability intersect.

Availability

LD29080PT25R is available at Aetrix Electronics and suitable for industrial PLC I/O modules, portable medical sensor nodes, embedded vision camera cores, and automotive infotainment USB hubs requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LD29080PT25R 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 devices for industrial, automotive, and consumer markets.

LD29080PT25R belongs to ST's high-accuracy, medium-current LDO family engineered for post-regulation in noise-sensitive and thermally constrained systems - emphasizing ultra-low dropout, tight output tolerance, and integrated protection.

FAQ

What is the minimum load current required for stable operation?

The LD29080PT25R requires a minimum load current of 2 mA across its full operating temperature range (−40 °C to +125 °C) to prevent output voltage rise caused by internal leakage currents. This is specified in ST's datasheet (Note 4, Table 5) and applies regardless of input voltage or output load transients.

Can the INHIBIT pin be left floating?

No - the INHIBIT pin is not internally pulled up and must be actively driven to ≥2 V to enable regulation. Leaving it floating results in undefined behavior and likely disables the output. A 10 kΩ pull-up to VI or direct GPIO drive is required for reliable operation.

Is an external capacitor required on the ADJ pin?

No - the LD29080PT25R is the fixed 2.5 V version; its ADJ pin is not connected internally (NC). Table 2 confirms "ADJ/N.C." for fixed versions, and the pin description states "Not connected for fixed version." No external components are needed on Pin 5.

What thermal considerations apply for continuous 800 mA operation?

At 800 mA and 13 V input, power dissipation reaches ~8.4 W. With R_thJA = 100 °C/W (PPAK), junction temperature rise is ~840 °C above ambient - impossible without heatsinking. Derating is mandatory: at 25 °C ambient, max continuous current is ~400 mA unless PCB copper area and airflow are significantly enhanced per ST's thermal guidelines.