STMicroelectronics LD29150DT18

Overview

LD29150DT18 from STMicroelectronics is a 1.5 A, fixed-output (1.8 V), very low-dropout linear voltage regulator in PPAK package. It delivers ±1% output accuracy over -40 °C to +125 °C, achieves 0.4 V dropout at 1.5 A load, and integrates thermal shutdown and logic-controlled electronic shutdown. It is used in post-regulation of switching supplies and battery-powered systems requiring stable low-voltage rails.

For engineers reviewing the LD29150DT18 datasheet, LD29150DT18 pinout, LD29150DT18 application, or LD29150DT18 equivalent, this page provides verified electrical specifications, real-world use cases, validated alternatives, and supply-chain support for industrial and embedded power design.

Technical Context

The LD29150DT18 employs a PNP pass transistor architecture enabling ultra-low dropout voltage and minimal ground current. Its internal reference is trimmed to ±1% at 25 °C and maintains stability across temperature and load variations.

It features an inhibit (shutdown) input compatible with TTL/CMOS logic levels (V_IL ≤ 0.8 V, V_IH ≥ 2 V), allowing system-level power sequencing. Thermal shutdown activates at 150 °C, and short-circuit current is limited to 2.2 A under defined test conditions.

Key Specifications

Pinout & Package

LD29150DT18 is housed in a thermally enhanced PPAK-5 (Power Package) surface-mount package with exposed thermal pad. The package supports high power dissipation via PCB copper area and has R_thJC = 8 °C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout, fixed-output voltage regulator applications.

Compared with LD29150DT18R, the PPAK variant offers superior thermal resistance (R_thJC = 8 °C/W vs. DPAK's 8 °C/W but better board-level conduction), while TSM1083-1.8 trades shutdown control and tighter accuracy for cost-making LD29150DT18 optimal for thermally constrained, feature-complete designs.

Availability

LD29150DT18 is available at Aetrix Electronics and suitable for industrial PLCs, automotive infotainment systems, and medical wearable devices requiring stable component supply with guaranteed long-term availability.

Supply support for LD29150DT18 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 precision output are mandatory.

FAQ

What is the minimum input voltage required for LD29150DT18 to regulate 1.8 V at 1.5 A?

The minimum input voltage is determined by dropout: 1.8 V + 0.4 V = 2.2 V. However, the datasheet specifies VI ≥ 3 V for guaranteed performance across temperature and load. Below 3 V, regulation may degrade or cease, especially at high junction temperatures.

Can LD29150DT18 be used without the SHDN pin connected?

Yes. The SHDN pin is active-low and internally pulled up; leaving it unconnected defaults the device to ON mode. For robust noise immunity in noisy environments, ST recommends tying SHDN to IN through a 10 kΩ resistor or directly to IN if shutdown is unused.

Is an input capacitor required for stable operation?

An input capacitor is not strictly required for stability but is strongly recommended: a 330 nF ceramic capacitor placed close to the IN and GND pins reduces high-frequency noise and improves transient response. Without it, line rejection and startup behavior may degrade.

How does thermal performance differ between PPAK and DPAK packages for LD29150DT18?

Both packages share identical R_thJC = 8 °C/W, but PPAK's smaller footprint and optimized thermal pad design yield lower effective R_thJA on standard 4-layer PCBs (typically ~45 °C/W vs. DPAK's ~65 °C/W). This allows higher sustained current in compact layouts without forced air cooling.