STMicroelectronics LD29300D2M50

Overview

LD29300D2M50 from STMicroelectronics is a 5.0 V fixed-output, 3 A low-dropout linear voltage regulator in D2PAK package with ±1% output tolerance at 25 °C, 0.4 V typical dropout at 3 A, and logic-controlled electronic shutdown. It delivers stable power for post-regulation in switching supplies and battery-powered systems requiring high accuracy and ultra-low dropout.

For engineers reviewing the LD29300D2M50 datasheet, LD29300D2M50 pinout, LD29300D2M50 application, or LD29300D2M50 equivalent, key selection criteria include guaranteed 3 A output current, thermal/current protection, ground current under 100 mA at full load, and compatibility with 10 µF ceramic output capacitors.

Technical Context

This regulator uses a PNP pass transistor architecture enabling sub-0.5 V dropout at rated current while maintaining tight line and load regulation (≤0.5% and ≤1.0%, respectively). Its internal reference is trimmed to ±1% over temperature, and it integrates thermal shutdown and current limiting without external components.

The device supports logic-controlled inhibit functionality via a dedicated INH pin (V_IL = 0.8 V, V_IH = 2 V), allowing system-level power sequencing. Output noise is specified at 200 µV_RMS (10 Hz–100 kHz) at 100 mA load, confirming suitability for noise-sensitive analog rails.

Key Specifications

Pinout & Package

D2PAK (TO-263) package: surface-mount, isolated tab (connected to output), 3-pin configuration with exposed thermal pad for PCB heat sinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 5 V, 3 A LDO applications.

Compared with TPS7A4700RGWR and NCP1117ST50T3G, LD29300D2M50 uniquely balances 3 A output, 0.4 V dropout, and integrated shutdown-making it the only drop-in solution for high-current, space-constrained 5 V systems needing both efficiency and controllability.

Availability

LD29300D2M50 is available at Aetrix Electronics and suitable for computer systems, battery-powered instrumentation, and monitor power sequencing requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LD29300D2M50 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 since 1987.

The LD29300 series was developed for high-current, low-dropout applications in power supply post-regulation and battery-powered equipment where thermal efficiency and output accuracy are critical.

FAQ

What is the minimum input voltage required for LD29300D2M50 to regulate 5.0 V at 3 A?

The minimum input voltage is 5.4 V - calculated as VO + VDROP = 5.0 V + 0.4 V (typical dropout at 3 A). At 3 A and –40 °C to +125 °C, dropout may reach 0.7 V, so 5.7 V input ensures regulation across full temperature range. Input below 6 V risks dropout under worst-case conditions.

Can LD29300D2M50 be used without the INH pin connected?

Yes - the INH pin is optional. When left unconnected or pulled high (>2 V), the device operates normally. If unused, tie INH to VIN through a 10 kΩ resistor to avoid floating inputs. No pull-down is required; the regulator defaults to ON state with INH open.

What output capacitor value and type are required for stability?

A minimum 10 µF ceramic capacitor (X5R/X7R, 10 V rating) is required at the output. The datasheet confirms stability with 10 µF CO and shows optimal phase margin in Figure 15. Larger values (e.g., 47 µF) improve transient response but are not necessary for basic regulation.

How does thermal performance differ between D2PAK and TO-220 packages?

D2PAK has R_thJA = 60 °C/W vs. TO-220's 50 °C/W - meaning D2PAK runs ~10 °C hotter at same ambient and power dissipation. However, D2PAK's exposed pad enables superior PCB heat spreading; with ≥2 cm² 2-oz copper, its effective R_thJA approaches 35 °C/W, outperforming TO-220 in compact layouts.