STMicroelectronics LD29150DT15R

Overview

LD29150DT15R from STMicroelectronics is a 1.5 A, fixed-output (1.5 V), very low dropout linear voltage regulator in DPAK package. It delivers guaranteed 1.5 A output current with typ. 0.4 V dropout at full load, ±1% output voltage accuracy at 25 °C, and integrated thermal/current protection. It is used in post-regulation of switching supplies and low-voltage, high-current systems such as computer motherboards and battery-powered instrumentation.

For engineers reviewing the LD29150DT15R datasheet, LD29150DT15R pinout, LD29150DT15R application, or LD29150DT15R equivalent, key selection criteria include dropout voltage at 1.5 A, quiescent current under load, thermal shutdown threshold, output noise (72 µVRMS), and logic-controlled shutdown capability.

Technical Context

The LD29150DT15R employs a PNP pass transistor architecture enabling ultra-low dropout performance. Its internal reference is trimmed to ±1% over temperature, and it features an inhibit (shutdown) input compatible with TTL/CMOS logic levels (VIL ≤ 0.8 V, VIH ≥ 2 V).

Thermal protection activates at 150 °C junction temperature, and short-circuit current is limited to 2.2 A. The device maintains stability with a minimum 10 µF ceramic output capacitor and requires no external compensation.

Key Specifications

Pinout & Package

LD29150DT15R is housed in a thermally enhanced DPAK (TO-252) package with exposed thermal pad, offering R_thJC = 8 °C/W for efficient heat transfer to PCB copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout, 1.5 A linear regulator applications.

Compared with LD29150DT15R, the LD29150DT18R offers identical performance at 1.8 V with zero design change overhead, while the TLV1117-15CDCY trades shutdown capability and ultra-low dropout for smaller footprint - making it viable only in less demanding input-voltage or thermal environments.

Availability

LD29150DT15R is available at Aetrix Electronics and suitable for computer motherboard VRM post-regulation, battery-powered test equipment, industrial PLC I/O modules, and medical sensor nodes requiring stable component supply across multi-year production cycles.

Supply support for LD29150DT15R 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 devices for industrial, automotive, and consumer markets.

The LD29150 series belongs to ST's high-current LDO portfolio, engineered specifically for post-regulation in power-constrained, noise-sensitive systems where ultra-low dropout and precision output voltage are mandatory.

FAQ

What is the minimum input voltage required for LD29150DT15R to regulate 1.5 V at 1.5 A?

The minimum input voltage is 1.9 V, calculated as V_OUT + V_DROP = 1.5 V + 0.4 V (typical dropout at 1.5 A). Operation below this causes dropout mode, where output tracks input minus ~0.4 V. Absolute minimum VI is 2.5 V per Table 8 for adjustable versions, but fixed 1.5 V variants specify 1.9 V practical minimum.

Does LD29150DT15R require an external capacitor on the INH pin for stable shutdown control?

No external capacitor is required on the INH pin. The pin accepts direct TTL/CMOS logic-level signals (0 V for OFF, ≥2 V for ON) with input current ≤10 µA. A simple pull-up resistor to VI or microcontroller GPIO suffices; no filtering or debouncing capacitor is specified in the datasheet.

Can LD29150DT15R be paralleled for higher current output?

Paralleling is not recommended. The LD29150DT15R lacks built-in current-sharing features (e.g., current-sense outputs or master-slave control), and mismatched dropout voltages between units would cause uneven current distribution and potential thermal runaway. For >1.5 A, select a higher-current LDO or use a discrete solution.

What is the maximum allowable PCB copper area for thermal relief when using LD29150DT15R in DPAK package?

ST recommends a minimum 100 mm² copper pour connected to the exposed thermal pad (pin 2/GND) for optimal thermal performance. Larger copper areas (≥200 mm²) further reduce R_thJA from 100 °C/W toward 60–70 °C/W, enabling full 1.5 A operation at ambient temperatures up to 85 °C without forced air cooling.