STMicroelectronics LD1086V36

Overview

LD1086V36 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, guarantees ≤1.5 V dropout at full load, operates from −40 °C to +125 °C, and requires only a 10 µF output capacitor for stability. It serves as a primary post-regulator in industrial power supplies and embedded system rails.

For engineers reviewing the LD1086V36 datasheet, LD1086V36 pinout, LD1086V36 application, or LD1086V36 equivalent, key selection criteria include dropout voltage at 1.5 A, thermal resistance (R_thJA = 50 °C/W in TO-220), adjustable vs. fixed variants, quiescent current behavior under load, and compatibility with standard 3-terminal regulator footprints.

Technical Context

The LD1086V36 implements a PNP-based LDO architecture with internal bandgap reference and error amplifier, delivering fixed 3.3 V output without external resistors. Its dropout voltage remains stable across temperature (−40 °C to +125 °C) and load (0–1.5 A), with guaranteed max 1.5 V at rated current.

Quiescent current flows into the load-not wasted as bias-improving efficiency over legacy PNP regulators. Internal thermal and short-circuit protection activate at junction temperatures >150 °C or output shorts, enabling robust operation in unattended industrial environments.

Key Specifications

Pinout & Package

LD1086V36 is available in TO-220 (3-pin, through-hole), D²PAK, DPAK, D²PAK/A, and DFN8 (4×4 mm) packages. The metal tab is electrically connected to the OUTPUT pin in all variants.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM1117MPX-3.3 and TLV1117-33CDCYR, the LD1086V36 provides 50% higher current rating, tighter output tolerance, and superior thermal performance in TO-220 - making it the only choice among the three for sustained 1.5 A industrial loads requiring long-term stability.

Availability

LD1086V36 is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical instrumentation requiring stable component supply, long lifecycle support, and traceable sourcing.

Supply support for LD1086V36 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, power, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The LD1086 series belongs to ST's high-current LDO portfolio, engineered specifically for industrial and automotive applications demanding robust thermal performance, tight DC accuracy, and integrated protection in harsh operating environments.

FAQ

What is the minimum input voltage required for LD1086V36 to regulate 3.3 V at 1.5 A?

The minimum input voltage is 4.8 V - calculated as 3.3 V output plus maximum guaranteed dropout of 1.5 V at 1.5 A. Operation below this causes dropout mode, where output tracks input minus ~1.5 V. Input must also remain within absolute max rating (≤30 V).

Can LD1086V36 be used without an input capacitor?

While not strictly mandatory, a minimum 1 µF ceramic input capacitor placed near the IN pin is strongly recommended to suppress high-frequency noise and prevent instability during line transients. ST's datasheet shows degraded transient response without it, especially with long input traces.

Is the TO-220 package's metal tab electrically connected, and if so, to which pin?

Yes - the metal tab is internally connected to the OUTPUT pin in all TO-220, D²PAK, and DPAK variants. This requires electrical isolation from heatsinks unless the heatsink is referenced to the 3.3 V rail. Insulating pads or shoulder washers must be used if mounting to chassis ground.

How does LD1086V36 handle short-circuit conditions?

It features foldback current limiting: short-circuit current drops to ~50 mA when VO ≈ 0 V, reducing power dissipation and preventing thermal runaway. Combined with thermal shutdown (activates >150 °C junction), this enables safe indefinite short-circuit survival without external circuitry.