STMicroelectronics LD29080DT18R

Overview

LD29080DT18R from STMicroelectronics is a fixed-output 1.8 V, 800 mA low-dropout linear regulator in DPAK package, featuring 0.4 V typical dropout at full load, ±1% output voltage accuracy over temperature, and logic-controlled electronic shutdown. It delivers stable power for FPGA core rails, microcontroller I/O supplies, and battery-powered embedded systems requiring ultra-low dropout and low ground current.

For engineers reviewing the LD29080DT18R datasheet, LD29080DT18R pinout, LD29080DT18R application, or LD29080DT18R equivalent, key selection criteria include guaranteed 800 mA output current, 0.4 V dropout at 800 mA, 72 µV_RMS output noise (10 Hz–100 kHz), and thermal shutdown with internal current limiting - all validated across –40 °C to +125 °C operating range.

Technical Context

The LD29080DT18R implements a PNP-based LDO architecture with integrated reference, error amplifier, and pass transistor, enabling stable regulation with minimal external components (only input/output capacitors required). Its inhibit pin (INH) accepts TTL/CMOS-compatible logic control (VIH ≥ 2 V, VIL ≤ 0.8 V) for precise system-level power sequencing.

Designed for post-regulation after switching converters, it maintains regulation down to VI = VO + VDROP, supporting input voltages from 2.5 V to 13 V. Thermal protection activates at junction temperatures exceeding safe limits, and short-circuit current is internally limited to 1.2 A.

Key Specifications

Pinout & Package

DPAK (TO-252) package: thermally enhanced surface-mount outline with exposed drain pad for improved heat dissipation (R_thJA = 100 °C/W, R_thJC = 8 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM10803DTR and MCP1703T-1802E/MB, the LD29080DT18R uniquely combines 800 mA capability, 0.4 V dropout, and 72 dB PSRR - making it the only viable choice for high-current, low-noise, battery-constrained 1.8 V applications.

Availability

LD29080DT18R is available at Aetrix Electronics and suitable for FPGA power delivery, industrial microcontroller systems, and portable medical devices requiring stable component supply with full production lifecycle support.

Supply support for LD29080DT18R 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 specializing in power management, microcontrollers, and analog ICs, with manufacturing and design centers across Europe, Asia, and the Americas.

The LD29080 series belongs to ST's high-accuracy, medium-current LDO portfolio, engineered specifically for post-regulation in space-constrained, thermally demanding applications such as consumer electronics, industrial controls, and automotive infotainment.

FAQ

What is the minimum input voltage required for regulation at 1.8 V output?

The LD29080DT18R requires VI ≥ VO + VDROP. With 0.4 V typical dropout at 800 mA, regulation is maintained down to 2.2 V input. At lighter loads (150 mA), dropout drops to 0.1 V, allowing stable operation from 1.9 V - critical for deep battery discharge scenarios.

Does this regulator require an external capacitor on the ADJ pin?

No - the LD29080DT18R is the fixed-output variant; the ADJ pin is not connected internally. Only input (CI ≥ 330 nF) and output (CO ≥ 10 µF, low-ESR ceramic) capacitors are required. No compensation network or ADJ capacitor is needed.

How does the inhibit function behave during power-up?

The INH pin must be pulled to ≥2 V (e.g., via resistor to VI or system rail) to enable output. If left floating or tied to GND, the device remains in shutdown (VO = 0 V). No internal pull-up exists - external biasing is mandatory for normal operation.

Can this part be used in parallel to increase current capacity?

No - the LD29080DT18R lacks current-sharing features (e.g., current-sense pins or master/slave mode). Parallel connection risks thermal runaway due to mismatched dropout voltages and is not supported by ST. Use a single 800 mA unit or select a higher-current regulator.