STMicroelectronics LD1086D2T15R

Overview

LD1086D2T15R from STMicroelectronics is a fixed-output 1.5 A low-dropout linear voltage regulator delivering 1.5 V with ±1% tolerance at 25 °C, 1.3 V typical dropout at full load, and operation across –40 °C to +125 °C. It uses a D²PAK package with integrated thermal and current limiting, and is used in industrial power rails for FPGA core supplies and embedded microcontroller I/O banks.

For engineers reviewing the LD1086D2T15R datasheet, LD1086D2T15R pinout, LD1086D2T15R application, or LD1086D2T15R equivalent, key selection criteria include dropout voltage at 1.5 A, output tolerance over temperature, minimum required input capacitance (10 µF), and thermal resistance (R_thJC = 3 °C/W) for high-ambient designs.

Technical Context

The LD1086D2T15R implements a PNP-based LDO architecture with on-chip trimming for tight output accuracy and a dedicated adjust pin (for adjustable variants) that draws only 40–120 µA. Its quiescent current flows into the load-not wasted as bias-improving efficiency versus legacy regulators.

It features internal foldback current limiting, thermal shutdown at ~150 °C junction temperature, and stability with ≥10 µF ceramic or tantalum output capacitance. Dropout remains ≤1.5 V up to 1.5 A across the full –40 °C to +125 °C operating range.

Key Specifications

Pinout & Package

D²PAK (TO-263-3) package: surface-mount, exposed thermal pad, 3-pin configuration with integrated heatsink capability. Tab is electrically connected to OUTPUT for optimal thermal transfer.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD1086V15R, the D²PAK variant offers superior thermal performance for high-current SMT designs; versus TLV1117-15CDCYR, it delivers 50% more current with lower dropout and tighter tolerance-critical for thermally constrained industrial edge nodes.

Availability

LD1086D2T15R is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, medical diagnostics, and programmable logic controller applications requiring stable component supply, long-term lifecycle assurance, and AEC-Q100-compliant alternatives.

Supply support for LD1086D2T15R 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 analog, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

The LD1086 series targets high-reliability linear regulation in space-constrained, thermally demanding environments-emphasizing dropout performance, output accuracy, and ruggedness over wide temperature ranges.

FAQ

Is LD1086D2T15R pin-compatible with LM317-based designs?

Yes-LD1086D2T15R uses the same 3-pin D²PAK footprint as standard adjustable regulators like LM317, but with IN-OUT-GND pinout (not ADJ-OUT-IN). No layout change is needed if the original design used a fixed-output variant or accommodated pin reassignment.

What is the minimum input capacitor required for stability?

A 1 µF ceramic capacitor placed within 5 mm of the IN pin is mandatory for transient immunity and EMI suppression. The datasheet specifies no minimum for input capacitance regarding loop stability, but this value prevents oscillation during line transients per Figure 22–24 test conditions.

Does LD1086D2T15R require an output capacitor with ESR zero?

No-it is stable with low-ESR ceramic capacitors (≥10 µF) and does not require ESR zero or minimum ESR. Unlike older LDOs, its internal compensation eliminates ESR dependency, enabling smaller, cheaper MLCCs instead of bulkier tantalum or aluminum electrolytics.

Can LD1086D2T15R be paralleled for higher current?

No-parallel operation is not supported. The device lacks current-sharing circuitry or matching tolerance guarantees. Attempting parallel connection risks thermal imbalance and premature failure due to mismatched dropout and load regulation characteristics.