STMicroelectronics LD29150DT33R

Overview

LD29150DT33R from STMicroelectronics is a fixed-output 3.3 V, 1.5 A low-dropout linear regulator in PPAK package, designed for post-regulation in switching power supplies and battery-powered systems requiring ultra-low dropout (400 mV typ. at 1.5 A) and high accuracy (±1% output voltage over -40 to 125 °C). It integrates thermal shutdown, current limiting, and logic-controlled electronic shutdown.

For engineers reviewing the LD29150DT33R datasheet, LD29150DT33R pinout, LD29150DT33R application, or LD29150DT33R equivalent, key selection criteria include dropout voltage at full load, quiescent current under standby and active conditions, output noise (132 µVRMS), supply voltage rejection (52–67 dB), and thermal performance in compact PPAK packaging.

Technical Context

The LD29150DT33R employs a PNP pass transistor architecture enabling 400 mV typical dropout at 1.5 A output current, with internal reference voltage stability and feedback loop compensation optimized for 10 µF ceramic output capacitance. Its inhibit input (VINH) supports TTL/CMOS-compatible enable control with 0.8 V logic-low threshold and 2 V logic-high threshold.

Thermal protection activates at 150 °C junction temperature, and short-circuit current is limited to 2.2 A. The device operates across input voltages from 4.3 V to 13 V, with line regulation of 0.06–0.5 % and load regulation of 0.2–1.0 % over full temperature and load range.

Key Specifications

Pinout & Package

LD29150DT33R uses the PPAK (Power Package) thermally enhanced surface-mount package (6.0 × 6.6 × 2.4 mm), featuring an exposed thermal pad for direct PCB copper connection to improve heat dissipation (R_thJC = 8 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM1083-3.3 and MCP1703T-3302E/MB, the LD29150DT33R uniquely combines 1.5 A capability, 400 mV dropout, ±1% accuracy, integrated shutdown, and thermal protection - making it irreplaceable in high-reliability, high-current LDO applications demanding both precision and robustness.

Availability

LD29150DT33R is available at Aetrix Electronics and suitable for industrial PLCs, portable medical sensors, set-top box USB hubs, and automotive infotainment displays requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LD29150DT33R 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, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The LD29150 series belongs to ST's high-current LDO portfolio, engineered specifically for post-regulation in space-constrained, thermally demanding applications where ultra-low dropout and high accuracy are mandatory.

FAQ

What is the minimum input voltage required for LD29150DT33R to maintain regulation at 1.5 A?

The minimum input voltage is 3.7 V - calculated as 3.3 V output plus 0.4 V typical dropout - verified per Table 6 (VI = 4.3 V min. for full spec compliance, but functional down to 3.7 V). Below this, output voltage collapses nonlinearly due to pass transistor saturation.

Can LD29150DT33R operate without an output capacitor?

No. A minimum 10 µF ceramic output capacitor is mandatory for stability, as confirmed in Figure 18 (Stability vs. CO) and Section 3 Typical Application. Omitting it causes oscillation and potential damage; ESR must be ≤10 mΩ.

Is the thermal pad on the PPAK package electrically connected?

Yes - the exposed thermal pad is internally connected to GND, as shown in Figure 25 (PPAK outline) and confirmed in ST's PPAK mechanical drawings. It must be soldered to a dedicated GND plane with ≥4 thermal vias for optimal R_thJA performance.

Does LD29150DT33R support adjustable output voltage?

No - LD29150DT33R is a fixed 3.3 V version. Adjustable variants (e.g., LD29150PTR) exist with ADJ pin, but DT33R has internal feedback network and no ADJ terminal; pinout confirms only IN, OUT, GND, and VINH connections.