STMicroelectronics LD29300D2M33

Overview

LD29300D2M33 from STMicroelectronics is a 3.3 V, 3 A fixed-output low-dropout linear voltage 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 stable power for post-regulation in switching supplies and battery-powered systems requiring high accuracy and ultra-low dropout.

For engineers reviewing the LD29300D2M33 datasheet, LD29300D2M33 pinout, LD29300D2M33 application, or LD29300D2M33 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 capacitance.

Technical Context

This regulator uses a PNP pass transistor architecture enabling sub-0.5 V dropout at rated current. Internal circuitry integrates thermal shutdown, current limiting, and an inhibit input (INH) that enables logic-level ON/OFF control with 0.8 V/2 V thresholds.

It operates across –40 to +125 °C junction temperature and supports input voltages up to 30 V (with automatic shutdown above 14 V). Output noise is specified at 132 µV_RMS (10 Hz–100 kHz), and supply voltage rejection reaches 52–67 dB at 120 Hz.

Key Specifications

Pinout & Package

The LD29300D2M33 is housed in a surface-mount D2PAK (TO-263) package with exposed thermal pad for enhanced heat dissipation. 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 3.3 V, 3 A LDO applications.

Compared with TLV1117-33CDR and TPS7A8300RGRT, the LD29300D2M33 uniquely combines 3 A capability, logic-controlled shutdown, and robust protection in a thermally efficient D2PAK-making it optimal for high-reliability, medium-noise embedded power domains.

Availability

LD29300D2M33 is available at Aetrix Electronics and suitable for computer systems, battery-powered medical devices, and consumer displays requiring stable component supply and long-term production continuity.

Supply support for LD29300D2M33 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, sensors, and automotive-grade components.

The LD29300 series belongs to ST's high-current LDO portfolio, engineered specifically for post-regulation in switching power supplies and battery-powered equipment where ultra-low dropout and integrated protection are critical.

FAQ

What is the minimum input voltage required for LD29300D2M33 to regulate 3.3 V at 3 A?

The minimum input voltage is VO + VDROP = 3.3 V + 0.4 V = 3.7 V (typical). Per datasheet Table 7, VI must be ≥4.3 V across the full operating range to guarantee regulation at 3 A and –40 to +125 °C. Below 4.3 V, output may drop out of specification under worst-case conditions.

Does LD29300D2M33 require an external capacitor on the INH pin?

No external capacitor is required on the INH pin. The INH input has high impedance (<10 µA leakage) and is designed for direct connection to GPIO or logic-level signals. A pull-down resistor (e.g., 100 kΩ) is recommended if the control source is open-drain or undriven during power-up to ensure defined startup state.

Can LD29300D2M33 be used with ceramic output capacitors?

Yes-ST specifies stable operation with ≥10 µF ceramic output capacitance (X5R/X7R). The device is internally compensated and does not require ESR-based damping. Using ceramic capacitors improves transient response and eliminates electrolytic aging concerns in long-life applications.

How does the automatic shutdown above 14 V protect the device?

Above 14 V input, internal circuitry forces the pass transistor into cutoff, disabling output regardless of INH state. This prevents excessive power dissipation and thermal runaway when subjected to transient overvoltage (e.g., load dump in automotive-adjacent systems). Output resumes normally once VI drops below ~13.5 V.