STMicroelectronics LD29150PT50

Overview

LD29150PT50 from STMicroelectronics is a 5.0 V fixed-output, high-accuracy low-dropout linear regulator in PPAK package, delivering up to 1.5 A output current with 400 mV typical dropout at full load, ±1% output voltage accuracy at 25 °C, and integrated thermal shutdown and current limiting. It serves as a post-regulator in switching power supplies and primary voltage source in battery-powered systems requiring stable low-noise 5 V rails.

For engineers reviewing the LD29150PT50 datasheet, LD29150PT50 pinout, LD29150PT50 application, or LD29150PT50 equivalent, key selection criteria include dropout performance at 1.5 A, quiescent current behavior under varying load and input voltage, thermal resistance (R_thJC = 8 °C/W), and logic-controlled shutdown capability for power sequencing in embedded systems.

Technical Context

The LD29150PT50 implements a PNP pass transistor architecture with internal reference and error amplifier, enabling ultra-low dropout by minimizing saturation voltage across the pass element. Its inhibit (INH) pin supports TTL/CMOS-compatible logic control (V_IL ≤ 0.8 V, V_IH ≥ 2 V) for precise system-level power gating.

Designed for high-current, low-headroom applications, it maintains regulation down to VI – VO = 0.4 V at 1.5 A and exhibits 200 µV_RMS output noise (10 Hz–100 kHz) with 10 µF ceramic output capacitance. Thermal shutdown activates at 150 °C, and short-circuit current is limited to 2.2 A.

Key Specifications

Pinout & Package

LD29150PT50 uses the PPAK (Power Package) thermally enhanced surface-mount package (6.0 × 6.6 × 2.4 mm), optimized for high-current PCB thermal management via exposed drain pad soldered to large copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM1050-5.0TR and MCP1826T-5002E/DB, LD29150PT50 offers superior thermal performance (8 °C/W), lower logic-threshold INH pin for robust MCU interfacing, and lowest output noise in its class-making it optimal for noise-sensitive, thermally constrained, or power-sequenced applications.

Availability

LD29150PT50 is available at Aetrix Electronics and suitable for industrial PLCs, automotive infotainment systems, and portable medical devices requiring stable component supply with guaranteed long-term manufacturability and consistent parametric performance.

Supply support for LD29150PT50 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 silicon solutions for automotive, industrial, and consumer markets since 1987.

The LD29150 series belongs to ST's high-current LDO portfolio, engineered specifically for post-regulation in switched-mode power supplies and battery-powered equipment where ultra-low dropout, thermal robustness, and precision output stability are critical.

FAQ

What is the minimum input voltage required for LD29150PT50 to maintain 5.0 V output at 1.5 A?

The minimum input voltage is 5.4 V, calculated as VO + VDROP = 5.0 V + 0.4 V (typical dropout at 1.5 A). The device remains functional down to 6 V input per Table 7, but regulation is guaranteed only when VI ≥ VO + VDROP across temperature and load. Below this, output voltage sags nonlinearly.

Can LD29150PT50 operate without an output capacitor?

No. The datasheet mandates ≥10 µF ceramic output capacitance (X5R/X7R) for stability, as confirmed in Figure 18 (stability vs. CO). Omitting CO causes oscillation and potential damage due to phase margin loss in the internal control loop-this is not optional or design-dependent.

How does the INH pin behave during power-up and brown-out conditions?

When INH is left floating, internal pull-down ensures default disable state (high-Z output). During power-up, INH must be held ≤0.8 V until VI reaches ≥6 V to avoid premature enable; during brown-out, the device auto-shuts down if VI drops below 6 V regardless of INH state, per absolute maximum rating note.

Is the exposed thermal pad electrically isolated from other pins?

Yes. The PPAK exposed pad (Pin 6) is internally connected to GND and must be soldered exclusively to a PCB GND plane. It is not isolated-it carries full output current return path and must not contact any other net, including chassis ground or split planes, to prevent ground loops or thermal derating loss.