STMicroelectronics LD29300D2M50R

Overview

LD29300D2M50R from STMicroelectronics is a 3 A, fixed 5.0 V output low-dropout linear regulator in D2PAK package with ±1 % output voltage tolerance at 25 °C, 0.4 V typical dropout at 3 A, and logic-controlled electronic shutdown. It delivers high-accuracy post-regulation for switching power supplies and battery-powered systems requiring stable 5 V rails under high load.

For engineers reviewing the LD29300D2M50R datasheet, LD29300D2M50R pinout, LD29300D2M50R application, or LD29300D2M50R equivalent, key selection criteria include guaranteed 3 A output current, thermal/current protection, 5.0 V ±1 % accuracy across –40 to 125 °C, and compatibility with 10 µF output capacitance for stability.

Technical Context

This LDO employs internal current limiting and thermal shutdown circuitry to ensure safe operation under overload or overtemperature conditions. Its fixed 5.0 V output is trimmed at 25 °C with ±1 % initial tolerance and maintains ≤1.0 % load regulation across 10 mA–3 A output range.

The device features an inhibit (shutdown) control input with logic-compatible thresholds (VIL ≤ 0.8 V, VIH ≥ 2 V), enabling system-level power sequencing. Dropout voltage remains as low as 0.4 V (typ.) at full 3 A load and 125 °C junction temperature, supporting operation from inputs as low as 5.4 V.

Key Specifications

Pinout & Package

D2PAK (TO-263) thermally enhanced surface-mount package with exposed drain pad for efficient heat transfer. Pin 1 = Input (VI), Pin 2 = Ground (GND), Pin 3 = Output (VO), Pin 4 = Inhibit (INH).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM1050DTR and LP3878MRX-5.0, LD29300D2M50R uniquely combines 3 A capability, 0.4 V dropout, integrated thermal/current protection, and logic-compatible shutdown in a single D2PAK package - making it optimal for industrial and consumer systems demanding robustness and design simplicity.

Availability

LD29300D2M50R is available at Aetrix Electronics and suitable for computer systems, monitor power supplies, and battery-powered systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LD29300D2M50R 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 silicon solutions for automotive, industrial, and consumer markets.

The LD29300xx series belongs to ST's high-current LDO portfolio, engineered specifically for post-regulation in switching power supplies and high-reliability embedded systems where precision, thermal resilience, and protection integration are mandatory.

FAQ

What is the minimum input voltage required for LD29300D2M50R to regulate 5.0 V at 3 A?

The minimum input voltage is VO + VDROP = 5.0 V + 0.4 V = 5.4 V (typical at 3 A, 25 °C). At worst-case 0.7 V dropout (max, 125 °C), VI must be ≥5.7 V. Operation below 5.4 V results in unregulated output proportional to input minus dropout.

Can LD29300D2M50R be used without the INH pin connected?

Yes - the INH pin is internally pulled up; leaving it open defaults the device to enabled state. However, for reliable operation in noisy environments, tie INH to VI through a 10 kΩ resistor or directly to VI if shutdown is never required.

What output capacitor value and type are required for stability?

A minimum 10 µF low-ESR ceramic or tantalum capacitor is required on VO. ST recommends X7R dielectric ceramics with ≤100 mΩ ESR. Larger values (e.g., 47 µF) improve load-transient response but do not affect basic stability per datasheet Figure 15.

Does LD29300D2M50R require a heatsink in TO-220 applications?

No - the D2PAK package has R_thJC = 3 °C/W and is designed for PCB copper pour thermal relief. With ≥10 cm² 2-oz copper area under the exposed pad, it dissipates >5 W at 25 °C ambient. TO-220 variants (e.g., LD29300P2T50R) require external heatsinks above ~2 W dissipation.