STMicroelectronics LD29300P2M33R

Overview

LD29300P2M33R from STMicroelectronics is a 3.3 V, 3 A fixed-output low-dropout linear regulator in P2PAK 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 DC/DC converter outputs and battery-powered systems where ultra-low dropout and ground current are critical.

For engineers reviewing the LD29300P2M33R datasheet, LD29300P2M33R pinout, LD29300P2M33R application, or LD29300P2M33R equivalent, key selection criteria include guaranteed 3 A output current, thermal/current protection, shutdown control interface, and compatibility with 10 µF output capacitance for stability.

Technical Context

This LDO employs internal NPN pass transistor architecture with integrated current limiting and thermal shutdown circuitry. Its reference voltage is trimmed to ±1% at 25 °C and maintains load regulation within 1.0% across 10 mA–3 A output range.

The device features an inhibit (INH) input enabling logic-level ON/OFF control with 0.8 V logic-low threshold and 2 V logic-high threshold. Dropout voltage remains stable across –40 °C to 125 °C junction temperature, defined as the VI–VO differential at which VO drops to 99% of nominal value.

Key Specifications

Pinout & Package

P2PAK package: thermally enhanced surface-mount variant with exposed drain pad for PCB heat sinking; compatible with standard reflow profiles per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM1033W and LD2980ABU33R, LD29300P2M33R uniquely combines 3 A output, 0.4 V dropout, and logic-enabled shutdown in a thermally optimized P2PAK package - making it the sole option for high-current, dynamically controlled 3.3 V rails in industrial and portable equipment.

Availability

LD29300P2M33R is available at Aetrix Electronics and suitable for computer systems, industrial PLCs, battery-powered test equipment, and medical diagnostic subsystems requiring stable component supply and long-term manufacturability.

Supply support for LD29300P2M33R 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, mixed-signal, power, and microcontroller products for industrial, automotive, and consumer markets.

LD29300P2M33R belongs to ST's high-current LDO family engineered for post-regulation in power-constrained systems - emphasizing ultra-low dropout, thermal robustness, and integration of protection and control functions.

FAQ

What is the minimum input voltage required for LD29300P2M33R to regulate 3.3 V at 3 A?

The minimum operating input voltage is 4.3 V, derived from the 3.3 V output plus 0.4 V typical dropout at 3 A load. Below this, regulation fails and output collapses. The datasheet specifies VI ≥ 4.3 V for full 3 A operation across temperature.

Can LD29300P2M33R be used without the INH pin connected?

Yes - the INH pin is internally pulled up; leaving it unconnected defaults the device to active mode. However, for deterministic shutdown behavior, tie INH to GND via a switch or GPIO. Do not float in noise-prone environments.

What output capacitor is required for stability with LD29300P2M33R?

A minimum 10 µF low-ESR aluminum or tantalum capacitor is required, placed within 5 mm of the OUT and GND pins. Ceramic capacitors may be used if ≥10 µF and ESR ≥10 mΩ; lower ESR risks oscillation per Figure 15 in the datasheet.

How does thermal performance differ between P2PAK and TO-220 packages for this LDO?

P2PAK offers R_thJC = 3 °C/W (same as TO-220), but its surface-mount footprint enables larger copper pour on PCB, reducing effective R_thJA. Datasheet lists R_thJA = 60 °C/W for P2PAK vs. 50 °C/W for TO-220 - meaning P2PAK achieves lower junction temperature under identical board layout due to superior heatsinking capability.