STMicroelectronics LD29150DT50R

Overview

LD29150DT50R from STMicroelectronics is a fixed-output 5.0 V, 1.5 A low-dropout linear voltage regulator in PPAK package, designed for post-regulation in switching power supplies and battery-powered systems where ultra-low dropout (0.4 V typ. at 1.5 A) and low ground current are critical. It integrates thermal shutdown, current limiting, and logic-controlled electronic shutdown.

For engineers reviewing the LD29150DT50R datasheet, LD29150DT50R pinout, LD29150DT50R application, or LD29150DT50R equivalent, key selection criteria include guaranteed 1.5 A output current, ±1% output voltage accuracy over temperature, 0.4 V dropout at full load, 200 µV_RMS output noise (10 Hz–100 kHz), and PPAK thermal resistance of 8 °C/W junction-to-case.

Technical Context

The LD29150DT50R employs a high-gain, internally compensated NPN pass transistor architecture enabling stable regulation with minimal input–output differential. Its control loop maintains ±1% output accuracy across –40 °C to +125 °C junction temperature and load currents from 10 mA to 1.5 A.

It features an inhibit (shutdown) input compatible with TTL/CMOS logic levels (V_IL ≤ 0.8 V, V_IH ≥ 2 V), allowing system-level power sequencing. Thermal shutdown activates at 150 °C, and short-circuit current is limited to 2.2 A under 5.5 V differential.

Key Specifications

Pinout & Package

LD29150DT50R uses the PPAK (Power Package) thermally enhanced surface-mount package, featuring exposed drain pad for low thermal resistance (R_thJC = 8 °C/W) and compact footprint (6.0 × 6.4 mm).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO regulator applications.

Compared with LD29150PT50R, the DT50R offers identical electrical performance in a thermally optimized PPAK package better suited for automated SMT assembly and high-power density layouts; versus TLV1117-50, it delivers 87.5% higher current, 67% lower dropout, and integrated shutdown-making it essential for demanding industrial and battery-critical designs.

Availability

LD29150DT50R is available at Aetrix Electronics and suitable for computer power rails, battery-powered instruments, industrial HMI panels, and set-top box AV subsystems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LD29150DT50R 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The LD29150 series belongs to ST's high-current LDO portfolio, engineered specifically for post-regulation in switched-mode power supplies and battery-powered equipment where ultra-low dropout, precision output, and robust thermal behavior are mandatory.

FAQ

What is the minimum input voltage required for LD29150DT50R to maintain regulation at 1.5 A?

The minimum input voltage is 5.4 V - calculated as V_OUT + V_DROP = 5.0 V + 0.4 V (typical dropout at 1.5 A). At 125 °C junction temperature, worst-case dropout rises to 0.7 V, requiring VI ≥ 5.7 V for guaranteed regulation. Input voltage must not exceed 30 V per absolute maximum ratings.

Can LD29150DT50R be used without the INH pin connected?

Yes - the INH pin is internally pulled up, so leaving it open defaults the device to enabled operation. However, ST recommends tying INH to VI via a 10 kΩ resistor for noise immunity in electrically noisy environments. Floating INH may cause erratic enable/disable behavior if exposed to ESD or coupling.

What output capacitor is required for stability with LD29150DT50R?

A minimum 10 µF ceramic capacitor (X5R/X7R, 6.3 V rating) is required at the OUT pin, placed within 5 mm of the device. ST validates stability with 10 µF ±20%; values below 6 µF risk oscillation. ESR should be <100 mΩ; tantalum or aluminum electrolytics are not recommended due to higher ESR and aging effects.

How does thermal performance differ between PPAK and DPAK packages for LD29150DT50R?

Both packages share identical R_thJC = 8 °C/W, meaning heat transfers equally well from die to exposed pad. However, PPAK's smaller footprint and optimized thermal pad layout yield lower effective R_thJA in PCBs with large copper pours - typically 45–55 °C/W versus DPAK's 60–70 °C/W under identical 4-layer board conditions with 2-in² 2-oz copper.