STMicroelectronics LD1086D2MTR

Overview

LD1086D2MTR from STMicroelectronics is a 1.5 A adjustable low-dropout linear voltage regulator in D²PAK package, delivering ±1% output voltage tolerance at 25 °C and dropout as low as 1.3 V at full load. It supports input voltages up to 30 V and operates across –40 °C to +125 °C, used for stable local regulation in industrial power supplies and embedded control modules.

For engineers reviewing the LD1086D2MTR datasheet, LD1086D2MTR pinout, LD1086D2MTR application, or LD1086D2MTR equivalent, key selection criteria include dropout performance at 1.5 A, adjust-pin current stability (40–120 µA), thermal protection behavior, and compatibility with 10 µF minimum output capacitance for stability.

Technical Context

The LD1086D2MTR uses an NPN-based pass transistor architecture with internal bandgap reference and on-chip trimming, enabling tight ±1% output tolerance at 25 °C and ±2% over full temperature range. Its adjust pin draws only 40–120 µA, and quiescent current flows into the load-not wasted-improving efficiency versus legacy PNP regulators.

It integrates thermal shutdown and internal current limiting, with guaranteed dropout of ≤1.5 V at 1.5 A across –40 °C to +125 °C. The device requires only a 10 µF output capacitor for stability and supports both fixed-output (1.8 V/3.3 V/5 V) and adjustable configurations via external resistor divider.

Key Specifications

Pinout & Package

D²PAK (TO-263-3) package with exposed thermal pad; tab electrically connected to OUTPUT pin for optimal heat transfer and low-impedance return path.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV1117-33CDR, LD1086D2MTR offers adjustable output and +50% current headroom; versus LT1963AES8#TRPBF, it trades 0.95 V higher dropout for simpler 10 µF-only stability and integrated thermal protection without external components.

Availability

LD1086D2MTR is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, medical patient monitor front-ends, and telecom remote radio units requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for LD1086D2MTR 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, designing and manufacturing power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The LD1086 series belongs to ST's high-current linear regulator product line, engineered specifically for robust local regulation in harsh environments-emphasizing thermal resilience, wide VIN range, and tight output accuracy without external compensation.

FAQ

What is the minimum output capacitor required for stability?

The LD1086D2MTR requires a minimum 10 µF output capacitor-ceramic, tantalum, or aluminum electrolytic-with ESR between 0.1 Ω and 10 Ω. Lower ESR capacitors (e.g., X7R ceramic) are acceptable if bulk capacitance remains ≥10 µF; no additional series resistor is needed.

Can LD1086D2MTR be used in adjustable mode with 2.85 V output?

Yes. Using the internal 1.25 V reference, a standard resistor divider (e.g., R1 = 1.24 kΩ, R2 = 1.58 kΩ, 1% tolerance) sets 2.85 V output. Adjust pin current (40–120 µA) introduces <0.1% error at typical divider currents of 1 mA-well within ±1% total tolerance.

Does the D²PAK tab require electrical isolation from PCB ground?

Yes-the tab is internally connected to the OUTPUT pin. If the output voltage differs from PCB ground (e.g., 3.3 V rail), the tab must be isolated using non-conductive thermal pads or solder mask openings. Direct mounting to grounded heatsinks will short the output to ground.

How does thermal protection behave under sustained overload?

When junction temperature exceeds ~165 °C, the LD1086D2MTR enters thermal shutdown-holding output at zero until die cools by ~15 °C. Recovery is automatic and does not require power cycle. This protects against permanent damage during prolonged short-circuit or excessive ambient conditions.