STMicroelectronics LD29300D2T33R

Overview

LD29300D2T33R from STMicroelectronics is a 3.3 V, 3 A fixed-output 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 serves as a post-regulation stage in high-current power supplies for computer systems and battery-powered equipment requiring stable, low-noise 3.3 V rails.

For engineers reviewing the LD29300D2T33R datasheet, LD29300D2T33R pinout, LD29300D2T33R application, or LD29300D2T33R equivalent, key selection criteria include guaranteed 3 A output current, 0.4 V dropout at full load, thermal/current protection, shutdown control interface, and compatibility with 10 µF output capacitance.

Technical Context

This regulator employs a PNP pass transistor architecture enabling ultra-low dropout voltage and stable operation with ceramic output capacitors ≥10 µF. Its internal circuit integrates precision bandgap reference, error amplifier, current-limit foldback, and thermal shutdown with hysteresis.

The device features an inhibit (INH) input that enables logic-level ON/OFF control with 0.8 V low threshold and 2 V high threshold, drawing only 5–10 µA at 13 V. Output noise is specified at 132 µV_RMS (10 Hz–100 kHz) under 100 mA load.

Key Specifications

Pinout & Package

LD29300D2T33R is housed in a surface-mount D2PAK (TO-263) package with exposed thermal pad for enhanced heat transfer. The package measures 10.0–10.4 mm length × 8.95–9.35 mm width × 4.4–4.6 mm height (JEDEC MS-013AC variant).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3.3 V, 3 A LDO regulator applications.

Compared with TLV1117-33CDR and TPS75233QPWPRQ1, LD29300D2T33R offers superior thermal resistance (3 °C/W vs. >50 °C/W in SO-8), native 3 A capability without derating, and logic-compatible shutdown-making it optimal for high-power industrial and computing applications where board space and thermal headroom are constrained.

Availability

LD29300D2T33R is available at Aetrix Electronics and suitable for computer systems, battery-powered equipment, and power supply post-regulation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for LD29300D2T33R 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 high-efficiency power architectures where ultra-low dropout, thermal robustness, and logic-controlled enable are critical.

FAQ

What is the minimum input voltage required for LD29300D2T33R to regulate 3.3 V at 3 A?

The minimum input voltage is 3.7 V - calculated as 3.3 V output plus 0.4 V typical dropout at 3 A. Absolute minimum VI is specified as 4.3 V across –40 to +125°C to guarantee regulation under worst-case conditions including tolerance and temperature drift.

Can LD29300D2T33R operate without an output capacitor?

No. A minimum 10 µF ceramic output capacitor is mandatory for stability, as confirmed in the application circuit and Figure 11 (Stability vs CO). Omitting it risks oscillation, output overshoot, and thermal runaway under load transients.

How does the INH pin behave during power-up and shutdown sequences?

The INH pin is active-low with 0.8 V logic low threshold. When pulled below 0.8 V, the output enters high-impedance state with <180 µA quiescent current. During power-up, INH must be held high (>2 V) before or concurrent with input voltage application to avoid undefined startup behavior.

Is LD29300D2T33R compatible with ceramic capacitors having X7R dielectric?

Yes. The datasheet specifies stability with ≥10 µF ceramic output capacitors and shows stable operation in Figure 11 across CO values from 4.7 µF to 100 µF. X7R ceramics meet ESR and capacitance requirements and are recommended for their temperature stability and low ESL.