STMicroelectronics LD1086D2M33TR

Overview

LD1086D2M33TR from STMicroelectronics is a fixed-output 3.3 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 requiring tight regulation under varying load and temperature.

For engineers reviewing the LD1086D2M33TR datasheet, LD1086D2M33TR pinout, LD1086D2M33TR application, or LD1086D2M33TR equivalent, key selection criteria include dropout voltage at 1.5 A, output tolerance across –40 °C to +125 °C, quiescent current behavior under light load, and compatibility with 10 µF minimum output capacitance for stability.

Technical Context

The LD1086D2M33TR uses a PNP-based pass transistor architecture with on-chip trimming for high initial accuracy, enabling ±1% output voltage tolerance at 25 °C and ±2% over full temperature range. Its dropout voltage remains ≤1.5 V up to 1.5 A output current, decreasing at lower loads.

Quiescent current flows into the load rather than being wasted as bias current-unlike traditional PNP regulators-improving efficiency especially at light loads. Stability requires only a 10 µF ceramic or tantalum output capacitor, with no external compensation needed for fixed-voltage variants.

Key Specifications

Pinout & Package

LD1086D2M33TR is housed in a surface-mount D²PAK (TO-263) package with exposed thermal pad. The TAB is electrically connected to the OUTPUT pin, requiring appropriate copper pour and thermal vias for effective heat transfer.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TLV1117-33CDR and MCP1703T-3302E/MB, the LD1086D2M33TR uniquely balances high output current (1.5 A), low dropout (1.3 V), wide input range (up to 30 V), and industrial temperature rating-making it the sole option among the three for thermally demanding, high-current embedded power rails.

Availability

LD1086D2M33TR is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and medical instrumentation requiring stable component supply with long-term manufacturability and AEC-Q100-aligned reliability.

Supply support for LD1086D2M33TR 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, specializing in power management, microcontrollers, and automotive-grade ICs with vertical manufacturing and AEC-Q100 qualification capabilities.

The LD1086 series was designed for industrial and automotive power regulation-emphasizing robustness, thermal resilience, and pin-compatible upgrade paths from legacy LDOs in harsh-environment applications.

FAQ

What is the minimum input voltage required for LD1086D2M33TR to maintain regulation at 1.5 A?

The minimum input voltage is calculated as V_OUT + V_DROP = 3.3 V + 1.5 V = 4.8 V (max dropout per datasheet). At 1.5 A and 25 °C, typical dropout is 1.3 V, so 4.6 V suffices. However, design margin requires ≥4.9 V input to guarantee regulation across temperature and process variation, as specified in Table 5 for LD1086#33.

Can LD1086D2M33TR be used without an input capacitor?

No. While the datasheet specifies a minimum 10 µF output capacitor for stability, an input capacitor (≥1 µF ceramic, placed close to IN and GND pins) is mandatory to suppress high-frequency noise and prevent oscillation during line transients. Omission risks instability, especially with long input traces or shared supply rails.

Is the D²PAK package thermally enhanced compared to TO-220 for this device?

Yes. The D²PAK (R_thJA = 62.5 °C/W) offers better thermal performance than TO-220 (R_thJA = 50 °C/W) *only when mounted on a 1-inch² 2-oz copper pad with ≥6 thermal vias*. In standard FR-4 with minimal copper, TO-220 outperforms D²PAK due to its exposed metal tab; proper PCB layout is essential to realize D²PAK's advantage.

Does LD1086D2M33TR require a minimum load current to maintain regulation?

No. Unlike some older LDOs, the LD1086D2M33TR has no minimum load requirement. It maintains regulation from zero load up to 1.5 A. This is confirmed in Table 7 and 8, where load regulation is specified from IO = 0 mA to 1.5 A, and the "IO(min)" parameter applies only to adjustable versions using the ADJ pin.