STMicroelectronics LD1086D2M18TR

Overview

LD1086D2M18TR from STMicroelectronics is a fixed-output 1.8 V, 1.5 A low-dropout linear voltage regulator in D²PAK package, featuring ±1% output tolerance at 25 °C, 1.3 V typical dropout at full load, and internal thermal/overcurrent protection. It delivers stable power to microcontroller cores, FPGA I/O banks, and industrial sensor signal chains where input-to-output headroom is constrained.

For engineers reviewing the LD1086D2M18TR datasheet, LD1086D2M18TR pinout, LD1086D2M18TR application, or LD1086D2M18TR equivalent, key selection criteria include guaranteed 1.5 A output current under 1.5 V dropout, ±2% output tolerance across –40 °C to +125 °C, D²PAK thermal resistance (R_thJC = 3 °C/W), and compatibility with ≥10 µF ceramic output capacitance for stability.

Technical Context

The LD1086D2M18TR implements a PNP-based LDO architecture with on-chip trimming for tight initial accuracy and temperature-compensated bandgap reference. Its adjust pin (for adjustable variants) is repurposed as ground in fixed versions like this one, simplifying PCB layout while retaining thermal foldback and short-circuit current limiting.

Unlike traditional PNP regulators, its quiescent current flows into the load rather than being wasted-improving efficiency at light loads. The device requires no external compensation when using ≥10 µF output capacitance with ESR ≤ 1 Ω, enabling robust transient response in space-constrained applications.

Key Specifications

Pinout & Package

D²PAK (SMD 3L STD-ST) package: thermally enhanced surface-mount outline with exposed tab electrically connected to OUTPUT; requires solder pad for thermal conduction to PCB plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV1117-18CDR and TPS7A4701RGWR, the LD1086D2M18TR uniquely balances 1.5 A capability, D²PAK thermal efficiency, and industrial temperature support - making it optimal for high-power embedded controllers where both current and ruggedness are non-negotiable.

Availability

LD1086D2M18TR 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 LD1086D2M18TR 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 silicon solutions for smart driving, power management, and embedded processing.

The LD1086 series targets industrial and automotive power regulation, emphasizing thermal robustness, wide input range, and high-current capability in compact packages - addressing needs beyond consumer-grade LDOs.

FAQ

Is LD1086D2M18TR pin-compatible with adjustable LD1086 variants?

No - LD1086D2M18TR uses a 3-pin D²PAK configuration (IN, OUTPUT, GND), whereas adjustable versions have IN, OUTPUT, and ADJ pins. The ADJ pin is internally grounded in fixed-output variants, so direct substitution requires PCB layout modification to route GND to pin 3 instead of ADJ.

What is the minimum output capacitance required for stability?

A minimum 10 µF ceramic capacitor with ESR ≤ 1 Ω is required at the output. STMicroelectronics validates stability with X5R/X7R dielectrics; smaller values risk oscillation under load transients, especially above 500 mA.

Can LD1086D2M18TR operate with an input voltage below 3.1 V?

No - the absolute minimum input voltage is 3.1 V (1.8 V + 1.3 V dropout). At lower inputs, regulation fails and output collapses. For sub-3.1 V operation, consider ultra-low-dropout alternatives like STLQ015 or TPS7A05.

Does LD1086D2M18TR require a heatsink in D²PAK package?

Not necessarily - with R_thJC = 3 °C/W and R_thJA ≈ 62.5 °C/W, a 4-layer PCB with 200 mm² copper pour under the tab limits junction rise to ~25 °C at 1.5 A ambient (25 °C). Heatsinks are only needed for >1.5 A or ambient >85 °C.