STMicroelectronics LD29300P2M25

Overview

LD29300P2M25 from STMicroelectronics is a 2.5 V fixed-output, 3 A low-dropout linear voltage regulator in P2PAK 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 high-current post-regulation in computer systems and battery-powered equipment where ultra-low dropout and ground current are critical.

For engineers reviewing the LD29300P2M25 datasheet, LD29300P2M25 pinout, LD29300P2M25 application, or LD29300P2M25 equivalent, key selection criteria include guaranteed 3 A output current, thermal/current protection, 100 µVRMS output noise (10 Hz–100 kHz), and compatibility with 10 µF ceramic output capacitors.

Technical Context

This regulator uses a PMOS pass transistor architecture enabling 0.4 V dropout at full 3 A load and maintaining regulation down to VI = VO + 0.4 V across –40°C to 125°C junction temperature. Internal protection includes thermal shutdown and current limiting, activated before device damage occurs.

The inhibit function is implemented via a dedicated INH pin accepting TTL/CMOS-compatible logic levels (VIL ≤ 0.8 V, VIH ≥ 2 V), enabling system-level power sequencing and standby mode control without external circuitry. Quiescent current remains as low as 130–180 µA in shutdown.

Key Specifications

Pinout & Package

P2PAK (Power Package) thermally enhanced surface-mount package with exposed drain pad for PCB heat sinking; footprint compatible with D2PAK but optimized for higher thermal performance in compact layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout, high-current regulator applications.

Compared with LD29300P2M25, the D2M25 variant offers identical regulation performance but demands more PCB area and different thermal interface design, while the P2T25 provides identical functionality in tape format-making P2M25 optimal for prototyping, low-volume builds, and thermal-critical applications where manual heatsink attachment is used.

Availability

LD29300P2M25 is available at Aetrix Electronics and suitable for computer systems, portable battery-powered devices, monitor power supplies, and VCR/TV series regulation requiring stable component supply and long-term manufacturability.

Supply support for LD29300P2M25 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, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The LD29300 series belongs to ST's high-current LDO portfolio, engineered specifically for post-regulation in switching power supplies and battery-powered systems where minimal dropout, precision output, and robust protection are mandatory.

FAQ

What is the minimum input voltage required for LD29300P2M25 to maintain 2.5 V output at 3 A?

The minimum input voltage is VO + VDROP = 2.5 V + 0.4 V = 2.9 V under typical conditions. Per Absolute Maximum Ratings, VI must remain ≥2.5 V across –40°C to 125°C, and dropout rises to 0.7 V max at 3 A and high temperature-so 3.2 V is recommended for full-spec margin.

Can LD29300P2M25 operate without the INH pin connected?

Yes. The INH pin is internally pulled up; leaving it open defaults the device to enabled (ON) state. However, for deterministic behavior in noisy environments, ST recommends tying INH to VI through a 10 kΩ resistor or actively driving it to avoid floating states that may cause erratic shutdown.

What output capacitor value and type are required for stability?

A minimum 10 µF ceramic capacitor (X5R/X7R, 6.3 V rating or higher) is required at the OUT pin. ST specifies CO ≥10 µF with ESR ≤100 mΩ; tantalum or aluminum electrolytics are not recommended due to ESR and aging effects that risk instability per Figure 11 (Stability vs CO).

How does thermal performance compare between P2PAK and D2PAK packages?

Both P2PAK and D2PAK share identical R_thj-case = 3°C/W, but P2PAK has lower R_thj-amb = 60°C/W vs D2PAK's 60°C/W (same value per datasheet page 3), meaning board-level thermal design dominates ambient performance. P2PAK's smaller footprint allows tighter layout, while D2PAK offers greater mechanical rigidity for screw-mounted heatsinks.