STMicroelectronics LD29300V50

Overview

LD29300V50 from STMicroelectronics is a fixed-output, 5.0 V, 3 A low-dropout linear voltage regulator in TO-220 package with ±1 % output voltage 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 LD29300V50 datasheet, LD29300V50 pinout, LD29300V50 application, or LD29300V50 equivalent, key selection criteria include guaranteed 3 A output current, thermal/current protection, 49–64 dB supply rejection at 120 Hz, 200 µVRMS output noise (10 Hz–100 kHz), and compatibility with 10 µF ceramic output capacitance.

Technical Context

The LD29300V50 integrates internal current limiting and thermal shutdown circuitry to prevent damage under overload or overtemperature conditions. Its fixed 5.0 V output is trimmed at 25 °C with ±1 % initial accuracy and maintains regulation across –40 °C to +125 °C junction temperature.

It features an inhibit input (INH) enabling logic-level ON/OFF control: VIH ≥ 2 V enables regulation, VIL ≤ 0.8 V forces shutdown with quiescent current reduced to 130–180 µA. Dropout voltage is defined as the VI–VO differential at which VO drops to 99 % of nominal under load.

Key Specifications

Pinout & Package

TO-220 package (3-pin, vertical mounting, exposed tab for thermal conduction). Pin 1: Input (VI), Pin 2: Ground (GND), Pin 3: Output (VO). Inhibit (INH) function is not implemented on the fixed-voltage LD29300V50 variant - INH pin is not connected per Figure 3 and footnote "* Not connected for fixed version."

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD29300V50, the D2PAK and P2PAK variants offer identical regulation performance but trade TO-220's ease of heatsinking and manual assembly for surface-mount scalability-requiring careful thermal layout to match the 50 °C/W junction-to-ambient resistance of the through-hole version.

Availability

LD29300V50 is available at Aetrix Electronics and suitable for power supply post-regulation, computer system rails, and battery-powered systems requiring stable component supply, long-term manufacturability, and industrial-grade thermal reliability.

Supply support for LD29300V50 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, analog chips, and MEMS sensors for industrial, automotive, and consumer markets.

The LD29300 series belongs to ST's high-current LDO portfolio, engineered specifically for applications demanding sub-0.5 V dropout, ±1 % accuracy, and integrated protection-targeting post-regulation, battery systems, and noise-critical embedded power rails.

FAQ

What is the minimum input voltage required for LD29300V50 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). Absolute maximum ratings specify VI must not exceed 30 V, and automatic shutdown activates above 14 V. Operation between 5.4 V and 13 V is recommended for full specification compliance.

Does LD29300V50 require an external capacitor on the INH pin?

No. The LD29300V50 is the fixed-output variant with no functional INH pin; Figure 3 and datasheet footnotes explicitly state "Not connected for fixed version." No external components are needed for inhibit functionality because it is unimplemented on this part number.

Can LD29300V50 be used with ceramic output capacitors?

Yes. The datasheet specifies CO = 10 µF ceramic in all electrical characteristics tables (e.g., Table 8), and Figure 15 ("Stability vs CO") confirms stable operation with 10 µF ceramic capacitors. ESR independence makes it compatible with low-ESR MLCCs without requiring series resistance.

What thermal derating applies when using LD29300V50 without a heatsink?

With R_thJA = 50 °C/W (TO-220), ambient temperature of 25 °C, and max junction temperature of 125 °C, the allowable power dissipation is (125–25)/50 = 2 W. At 3 A load and 0.4 V dropout, PD = 1.2 W - within limit. Derating begins above ~2.5 A if ambient exceeds 25 °C; a heatsink is recommended for sustained >2 A operation above 50 °C ambient.