STMicroelectronics LD1086V12

Overview

LD1086V12 from STMicroelectronics is a fixed-output 12 V, 1.5 A low-dropout linear voltage regulator in TO-220 package, designed for post-regulation in industrial power supplies and embedded systems requiring stable 12 V rail with ≤1.5 V dropout at full load, ±1% output tolerance at 25 °C, and internal thermal/overcurrent protection.

For engineers reviewing the LD1086V12 datasheet, LD1086V12 pinout, LD1086V12 application, or LD1086V12 equivalent, this page delivers verified electrical specs, package-specific pin mapping, real-world use cases in 12 V power domains, and validated alternative parts with documented functional differences.

Technical Context

The LD1086V12 integrates an NPN pass transistor architecture-unlike legacy PNP regulators-routing quiescent current into the load to improve efficiency. Its reference voltage (1.25 V) is trimmed on-chip to achieve ±1% initial accuracy, and internal compensation enables stability with only a 10 µF output capacitor.

Dropout voltage is guaranteed ≤1.5 V at 1.5 A across –40 °C to +125 °C, with thermal shutdown activating at ~150 °C junction temperature. Line regulation remains ≤10 mV over input range (13.5 V to 30 V), and load regulation holds ≤35 mV from no-load to full 1.5 A.

Key Specifications

Pinout & Package

LD1086V12 is supplied in TO-220 package (STD-ST dual gauge), with metal tab electrically connected to OUTPUT for direct heatsink mounting and low thermal resistance (R_thJC = 5 °C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM2940CT-12 and TLV1117-12, LD1086V12 uniquely combines 1.5 A output, 1.3 V dropout, and ±1% accuracy in TO-220-making it the sole choice for thermally demanding 12 V industrial rails where both current and precision are non-negotiable.

Availability

LD1086V12 is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, medical instrumentation, and test equipment requiring stable component supply with full production lifecycle support.

Supply support for LD1086V12 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, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

LD1086V12 belongs to ST's high-current LDO family, engineered specifically for robust, low-noise post-regulation in harsh-environment power systems where reliability and precision supersede cost-driven compromises.

FAQ

What is the minimum input voltage required for LD1086V12 to maintain regulation at 1.5 A?

The LD1086V12 requires a minimum input voltage of 13.5 V to sustain 12 V output at 1.5 A load, based on its guaranteed maximum dropout of 1.5 V. At lighter loads, dropout decreases-e.g., 1.0 V at 500 mA-allowing operation from as low as 13.0 V in partial-load conditions.

Can LD1086V12 be used without an input bypass capacitor?

No. An input bypass capacitor (≥1 µF ceramic) is mandatory to prevent oscillation and ensure transient response stability. Without it, the regulator may exhibit ringing or instability during line transients, especially with long PCB traces between input source and IC.

Is the metal tab on the TO-220 package electrically isolated?

No. The metal tab is internally connected to the OUTPUT pin. When mounted to a heatsink, the heatsink must be electrically isolated unless the system ground is tied directly to the 12 V output rail-otherwise, short-circuit or safety hazards will result.

Does LD1086V12 require an external resistor divider for feedback?

No. LD1086V12 is a fixed-output variant with internal resistor network set to 12 V. Unlike the adjustable LD1086 (which uses ADJ pin), this part has no adjustment terminal-pin 3 is GND, not ADJ-and operates as a true three-terminal device.