STMicroelectronics LD29150PT18

Overview

LD29150PT18 from STMicroelectronics is a 1.5 A, fixed 1.8 V low-dropout linear voltage regulator in PPAK package, featuring 400 mV typical dropout at full load, ±1% output accuracy over temperature, and logic-controlled electronic shutdown. It delivers stable power to core rails in battery-powered systems, post-regulation stages of switching supplies, and compact consumer electronics requiring ultra-low dropout and low quiescent current.

For engineers reviewing the LD29150PT18 datasheet, LD29150PT18 pinout, LD29150PT18 application, or LD29150PT18 equivalent, key selection criteria include guaranteed 1.5 A output current, 0.4 V dropout at 1.5 A, thermal shutdown at 150 °C, and compatibility with 10 µF ceramic output capacitors for stability.

Technical Context

The LD29150PT18 integrates an internal NPN pass transistor with precision bandgap reference and error amplifier, enabling high-accuracy regulation under varying load and line conditions. Its architecture supports fast transient response (load step recovery in <50 µs) and maintains stability with low-ESR ceramic capacitors as small as 10 µF.

It features dual protection: thermal shutdown at 150 °C and internal current limiting (2.2 A short-circuit current), plus logic-controlled inhibit functionality via the INH pin (VIH = 2 V, VIL = 0.8 V). Ground current remains below 80 mA at 1.5 A load and drops to 130–180 µA in shutdown mode.

Key Specifications

Pinout & Package

LD29150PT18 uses the thermally enhanced PPAK (Power Package) surface-mount package (6.0 × 6.6 × 2.4 mm), with exposed thermal pad for direct PCB copper connection to improve power dissipation. R_thJC = 8 °C/W enables >1 W continuous power handling with minimal board area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6215D182MR and NCP1117ST18T3G, LD29150PT18 uniquely combines 1.5 A capability, 0.4 V dropout, ±1% accuracy, and integrated INH control - making it the sole option for space-constrained, high-efficiency, and thermally demanding 1.8 V core rail applications.

Availability

LD29150PT18 is available at Aetrix Electronics and suitable for mobile processor core rails, USB-C PD auxiliary supplies, industrial sensor node power management, and automotive display logic rails requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LD29150PT18 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 analog components for industrial, automotive, and consumer markets.

LD29150PT18 belongs to ST's high-current LDO family engineered for post-regulation in power-constrained systems where ultra-low dropout, precision output, and integrated protection are mandatory - especially in battery-powered and thermally limited applications.

FAQ

What is the minimum input voltage required for LD29150PT18 to regulate 1.8 V at 1.5 A?

The minimum input voltage is 2.2 V, calculated as VO + VDROP = 1.8 V + 0.4 V (typical dropout at 1.5 A). The datasheet confirms stable regulation down to VI = 3.0 V for all test conditions, but operation at 2.2 V is feasible per the 0.4 V dropout spec and thermal limits - provided PCB thermal design sustains junction temperature ≤125 °C.

Can LD29150PT18 be used without an input bypass capacitor?

No - a minimum 330 nF ceramic capacitor at the IN pin is required per the datasheet (CI = 330 nF in all electrical characteristic test conditions). Omitting it risks instability, increased output noise, and potential oscillation due to inadequate high-frequency decoupling of the internal reference and error amplifier.

Does LD29150PT18 require a specific output capacitor ESR range?

No - unlike older LDOs, LD29150PT18 is optimized for low-ESR ceramic capacitors (≥10 µF) and does not require a minimum ESR. The datasheet specifies stability with 10 µF X7R ceramics (Figure 18), and adding series resistance degrades transient response and increases output impedance.

Is the INH pin internally pulled up or down when unconnected?

The INH pin has no internal pull-up or pull-down; it is a high-impedance CMOS input (I_INH ≤10 µA). Leaving it floating risks undefined operation - ST recommends tying INH to GND via a 100 kΩ resistor for default shutdown or to VIN via same for default enable, per application requirements.