STMicroelectronics LD1086V33

Overview

LD1086V33 from STMicroelectronics is a fixed-output 3.3 V, 1.5 A low-dropout linear voltage regulator in TO-220 and surface-mount packages. It delivers ±1% output tolerance at 25 °C, 1.3 V typical dropout at full load, and operates across –40 °C to +125 °C for industrial power rails in microcontroller core supplies and FPGA I/O banks.

For engineers reviewing the LD1086V33 datasheet, LD1086V33 pinout, LD1086V33 application, or LD1086V33 equivalent, key selection criteria include dropout voltage under 1.5 A load, thermal performance in DPAK/DFN8 packages, stability with 10 µF output capacitance, and compatibility with legacy adjustable regulator footprints.

Technical Context

The LD1086V33 integrates an internal bandgap reference (1.25 V), error amplifier, and NPN pass transistor-enabling high PSRR (79 dB @ 120 Hz) and low quiescent current (5–10 mA) that flows into the load rather than ground. Its architecture eliminates external feedback resistors required by adjustable variants, simplifying PCB layout for fixed 3.3 V systems.

Thermal protection activates at junction temperatures exceeding 150 °C, and short-circuit current is internally limited to 1.5–2 A depending on dropout voltage. The device requires only a single 10 µF minimum ceramic or tantalum output capacitor for stability across its full operating range.

Key Specifications

Pinout & Package

Available in TO-220 (3-pin, tab-connected to OUTPUT), DPAK (3-pin, tab-connected to OUTPUT), D²PAK (3-pin, tab-connected to OUTPUT), D²PAK/A (3-pin), and DFN8 (4×4 mm, 8-pin, exposed pad connected to OUTPUT). All variants share identical pin function mapping.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO applications.

Compared with LM1117MPX-3.3 and TLV73333PDBVR, the LD1086V33 uniquely combines 1.5 A output, industrial temperature rating, and 1.3 V dropout in TO-220/DPAK-making it optimal for thermally constrained, high-reliability 3.3 V power domains where both current and ruggedness are mandatory.

Availability

LD1086V33 is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical diagnostic equipment requiring stable component supply with long lifecycle assurance.

Supply support for LD1086V33 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, specializing in power management, microcontrollers, and automotive-grade ICs.

The LD1086 series was designed for high-current, low-dropout regulation in space-constrained industrial and automotive systems-emphasizing thermal resilience, tight output tolerance, and pin compatibility with legacy designs.

FAQ

What is the minimum input voltage required for LD1086V33 to maintain regulation at 1.5 A?

The LD1086V33 requires a minimum input voltage of 4.6 V to sustain 3.3 V output at 1.5 A load, based on its guaranteed 1.5 V maximum dropout voltage. At lighter loads, input can be reduced further-e.g., 4.0 V suffices at 500 mA due to lower dropout (≈0.7 V).

Can LD1086V33 be used with ceramic output capacitors?

Yes-LD1086V33 is stable with ceramic capacitors ≥10 µF and ESR as low as 5 mΩ. Unlike older LDOs, it does not require high-ESR tantalum or aluminum electrolytics, enabling smaller, more reliable, and longer-life output filtering.

Does LD1086V33 require an input bypass capacitor?

An input capacitor (≥1 µF ceramic) is strongly recommended to suppress high-frequency noise and prevent oscillation during fast line transients. While not strictly mandatory for DC stability, omission risks degraded PSRR and potential instability under dynamic load conditions.

How does the thermal performance differ between TO-220 and DFN8 packages?

TO-220 has R_thJA = 50 °C/W (no heatsink), while DFN8 (4×4 mm) achieves R_thJA = 33 °C/W with 1-in² 2-oz copper pad. In practice, the DFN8 delivers ~30% lower junction temperature at 1.5 A under identical PCB layout-making it preferable for compact, convection-cooled designs.