STMicroelectronics LD29150PT33

Overview

LD29150PT33 from STMicroelectronics is a fixed-output 3.3 V, 1.5 A low-dropout linear regulator in PPAK package with 400 mV typical dropout at full load, ±1% output voltage accuracy over temperature, and integrated thermal shutdown and current limiting. It delivers stable post-regulation for CPU core supplies in embedded computers and powers sensitive analog rails in battery-powered instrumentation.

For engineers reviewing the LD29150PT33 datasheet, LD29150PT33 pinout, LD29150PT33 application, or LD29150PT33 equivalent, key selection criteria include dropout performance at 1.5 A, quiescent current under light and heavy loads, output noise (132 µV_RMS), logic-controlled shutdown capability, and thermal resistance (8 °C/W junction-to-case).

Technical Context

The LD29150PT33 employs a high-gain bandgap reference and precision error amplifier to maintain ±1% output regulation across –40 °C to +125 °C junction temperature and 10 mA–1.5 A load range. Its PPAK package enables low thermal resistance (8 °C/W) for sustained 1.5 A operation without external heatsinking.

It integrates an inhibit input (VINH) compatible with TTL/CMOS logic levels (V_IL ≤ 0.8 V, V_IH ≥ 2 V), enabling system-level power sequencing. Internal protection includes foldback current limiting and thermal shutdown at 150 °C, with automatic recovery upon cooling.

Key Specifications

Pinout & Package

LD29150PT33 uses the STMicroelectronics PPAK (Power Package) thermally enhanced surface-mount package with exposed die pad for low thermal resistance. Dimensions per Table 10: D = 6.0–6.2 mm, E = 6.4–6.6 mm, H = 9.35–10.1 mm, e = 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TSM1083-3.3 and MCP1755ST-3302E, LD29150PT33 uniquely combines 0.4 V dropout, ±1% accuracy, integrated shutdown, and 8 °C/W thermal resistance-enabling compact, high-reliability 1.5 A regulation where input headroom and thermal management are constrained.

Availability

LD29150PT33 is available at Aetrix Electronics and suitable for embedded computer power, industrial sensor interfaces, battery-powered instrumentation, and set-top box AV subsystems requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LD29150PT33 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 space-constrained, thermally demanding systems where ultra-low dropout and precision output stability are mandatory.

FAQ

What is the minimum input voltage required for LD29150PT33 to regulate 3.3 V at 1.5 A?

The minimum input voltage is 3.7 V, calculated as VO + VDROP = 3.3 V + 0.4 V (typical dropout). At worst-case 0.7 V dropout, input must be ≥4.0 V. The device enters automatic shutdown above 14 V input, so operating range is strictly 3.7–13 V for full-load regulation.

Does LD29150PT33 require an external output capacitor, and what type is recommended?

Yes, a minimum 10 µF ceramic capacitor is required at the OUT pin for stability, as specified in Section 3 (Typical Application) and Figure 4 of the datasheet. X5R or X7R dielectrics are recommended; tantalum capacitors are not advised due to ESR sensitivity.

How does the VINH inhibit pin function, and what logic levels are compatible?

VINH is an active-low enable input: applying ≤0.8 V places the regulator in shutdown (quiescent current 130–180 µA); applying ≥2 V enables regulation. It is compatible with standard 3.3 V and 5 V CMOS/TTL outputs and has leakage ≤10 µA across temperature.

Can LD29150PT33 be used in parallel to increase output current beyond 1.5 A?

No-parallel operation is not supported. The device lacks current-sharing features such as current-sense pins or droop compensation. Attempting parallel connection risks thermal runaway due to mismatched dropout voltages and unbalanced load distribution.